JPH1180554A - Asphalt composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an asphalt composition excellent in high-temperature storage stability and the balance with binder properties, and suitable for road pavement and waterproof sheets or the like. SOLUTION: This asphalt composition mainly comprises (A) 100 pts.wt. of a block copolymer (mixture) of the formula A-B-A', A-B-A'-B or (A-B)n X (X is a coupling agent residue; (n) is an integer of 2-6; A and A' are each a polymer block consisting mainly of Gromatic vinyl compound 8,000-20,000 in weight average molecular weight; B is a polymer block consisting mainly of a conjugated diene; the weight-average molecular weight of the whole block copolymer is 100,000-400,000; the total bound A and A' content is 20-45 wt.%), (B) 2-15 pts.wt. of a naphthene-based and/or paraffin-based process oil, and (C) such an amount of straight asphalt 40-200 in penetration as to be (2:98) to (20:80) in the weight ratio C/(A+B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an asphalt composition, and more particularly to a straight asphalt,
The present invention relates to an asphalt composition comprising a block copolymer of an aromatic vinyl compound and a conjugated diene and a process oil, which has improved compatibility with asphalt and excellent storage stability.

[0002]

2. Description of the Related Art Conventionally, asphalt is inexpensive and easily available, and is used for road pavement, waterproof sheet, soundproof sheet,
Widely used for applications such as vibration damping materials. However, asphalt is inferior in softening point and penetration,
Attempts have been made to improve these characteristics so as to meet higher required characteristics. For example, attempts have been made to add various polymers as a means of improving the properties of asphalt. Specific examples of this polymer include styrene-butadiene random copolymer latex (SBR latex), ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer, and the like.

In recent years, attempts have been made to modify asphalt by adding a block copolymer of an aromatic vinyl compound and a conjugated diene (SB block copolymer). For example, for the purpose of improving various physical properties of asphalt, various asphalt compositions to which a block copolymer having a specific structure is added have been proposed. That is, Japanese Patent Publication No. 47-17319 discloses the use of an ABA type linear block copolymer, and Japanese Patent Publication No. 49-17007 discloses an ABAB type linear block copolymer. The use of
JP-B-59-36949 discloses the use of a radial block copolymer represented by the (AB) nX type, and JP-A-5-279574 discloses an ABA-type linear block copolymer. A combination use of the union and (AB) nX type radial block copolymer is disclosed. However, in these disclosed examples, although binder properties such as asphalt softening point and toughness and tenacity are considerably improved, storage stability at high temperatures is not always sufficient.

[0004] For this reason, generally, these properties have been improved by addition of an aromatic oil and crosslinking by addition of sulfur or peroxide. For example, the Journal of the Institute of Petroleum (Jour
Vol. 59, p. 566 (1973) discloses the use of aroma oils and U.S. Pat. Nos. 3,963,659 and 4,503,176 disclose the use of peroxides. Japanese Patent Publication No. 24385/1990 discloses the use of sulfur, and Japanese Patent Publication No. 1-17433 discloses the use of a polysulfide having a specific structure.
No. 035 discloses the combination use of sulfur with a vulcanizing agent and a sulfur donor vulcanization accelerator.

[0005] However, addition of an aroma-based oil is effective in high-temperature storage stability and dissolution time, but deteriorates fluidity and abrasion resistance after construction, and causes problems such as rutting. Further, although crosslinking by sulfur or peroxide is effective for storage stability, there is a problem that the dissolving time of the asphalt composition is significantly increased and processability is impaired. Further, the polysulfide having a specific structure described in the above patent is a diblock copolymer in which a good balance of mechanical properties and processability can be obtained as a cross-linking effect, but it is not sufficient.
There is a practical problem due to the peculiar off-flavor. Furthermore, when the above-mentioned polysulfide is applied to a triblock copolymer, there is a problem that the melt viscosity becomes extremely high and processability is impaired. As described above, attempts to modify asphalt using a block copolymer and an additive having a specific structure have not yet yielded satisfactory results, and high-temperature storage stability, dissolution time, binder properties, At present, there is no modifier that satisfies the balance between workability and physical properties after construction, and further improvement is desired.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has improved storage stability at high temperatures, and is excellent in the balance of binder physical properties, workability, and physical properties after construction. It is an object of the present invention to provide an asphalt composition that can be used for road pavement, a waterproof sheet, and the like.

[0007]

According to the present invention, there is provided (A) a compound represented by the following general formula: ABA ', ABA'-B or (A-
B) nX (where X is a residue of a coupling agent, and n is 2 to 2)
An integer of 6, A to A 'are polymer blocks mainly composed of an aromatic vinyl compound having a weight average molecular weight of from 88,000 to 20,000,
Is a polymer block mainly composed of a conjugated diene, the weight average molecular weight of the entire block copolymer is 100,000 to 400,000,
The total bond content of A and A 'is from 20 to 45% by weight), or a mixture thereof, (b) a naphthenic and / or paraffinic process oil, and (c) a needle The main component is straight asphalt having a degree of 40 to 200, the component (b) is 2 to 15 parts by weight, the total amount of the component (a) and the component (b) and the component (c) are 100 parts by weight of the component (a). And a weight ratio of 2/98 to 20/80 with the asphalt composition.

[0008]

DETAILED DESCRIPTION OF THE INVENTION The component (A) used in the present invention comprises polymer blocks A and A 'mainly composed of an aromatic vinyl compound and a polymer block B mainly composed of a conjugated diene.
Is ABA ', ABA'-B, or (A
-B) nX (where X is the residue of a coupling agent and n is 2
(Indicating an integer of ~ 6) or a mixture thereof. The diblock copolymer type A-B may be contained in the entire block copolymer as a residue of the coupling reaction. However, when used alone, the effect of improving the softening point and toughness / tenacity is low, which is not preferable. Block B is a homopolymer block of a conjugated diene or a copolymer block of a conjugated diene and an aromatic vinyl compound containing 50% by weight or more of a conjugated diene. The aromatic vinyl compound which may be present in the block B may be distributed uniformly or in a tapered shape. A plurality of the uniformly distributed portions and / or the tapered portions may coexist in the block B.

Here, (a) the aromatic vinyl compound used to obtain the block copolymer includes styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1- Examples thereof include diphenylstyrene, N, N-dimethyl-p-aminoethylstyrene, N, N-diethyl-p-aminoethylstyrene, and vinylpyridine, and styrene and α-methylstyrene are particularly preferable.

Also, (a) conjugated dienes used for obtaining a block copolymer include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, -Methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-
Examples include 1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene, and the like, preferably 1,3-butadiene, isoprene, and 1,3-pentadiene, and particularly preferably 1,3-butadiene. is there.

(A) Block A in the block copolymer,
A 'is a polymer block mainly composed of an aromatic vinyl compound, and may be a copolymer of less than 50% by weight of a conjugated diene. The blocks A and A 'may be equal or unequal. Block A,
The weight average molecular weight of A 'is from 80,000 to 20,000, preferably from 90,000 to 180,000. Weight average molecular weight is 0.8
If it is less than 10,000, the dissolution time in asphalt is short, and processing and handling are easy.However, the softening point and toughness and tenacity are insufficient, and if it exceeds 20,000, the softening point and toughness and tenacity are sufficient. However, the melting time of the asphalt composition increases, and the processing and handling become difficult.

The weight average molecular weight of the entire block copolymer (a) is 100,000 to 400,000, preferably 120,000 to 38.
It is ten thousand. If the weight-average molecular weight is less than 100,000, the obtained asphalt composition has insufficient softening point, toughness and tenacity, and also has a large decrease in flow resistance. On the other hand, if it exceeds 400,000, the toughness and tenacity are sufficiently large, but the compatibility with the asphalt becomes poor and the phase is easily separated, and the melt viscosity of the asphalt composition becomes high, making the processing and handling difficult. .

Further, (a) the total bonding content of the blocks A and A 'in the block copolymer is 20 to 45% by weight, preferably 23 to 40% by weight. If the total bonding content is less than 20% by weight, the softening point, toughness and tenacity are insufficient, and the fluid deformation resistance at high temperatures is also insufficient. On the other hand, if it exceeds 45% by weight, the penetration of the asphalt composition becomes small and hard, and the low-temperature flexibility decreases.

The block copolymer (a) used in the present invention is prepared by first polymerizing an aromatic vinyl compound in an inert hydrocarbon solvent using an organic alkali compound such as an organic lithium compound as a polymerization initiator. Then, after polymerizing the conjugated diene, again polymerizing the aromatic vinyl compound, and then reacting the conjugated diene again,
Polymerization is carried out step by step, or the aromatic vinyl compound is first polymerized, then the conjugated diene is polymerized, and then the coupling agent is reacted, or the aromatic vinyl compound is polymerized again after the conjugated diene to form a cup. It can be produced by reacting a ring agent. In addition,
In the above general formula, n is determined by the functional number of the coupling agent, and is an integer of 2 to 6, preferably 2 to 4. When n exceeds 6, the weight average molecular weight of the triblock is extremely large. The viscosity of the asphalt composition increases, which is not preferable. Further, when n is 1, for example, a diblock copolymer of AB is used, and the use of this block copolymer alone is not preferred because the effects of improving the softening point and toughness / tenacity are low.

Examples of the inert hydrocarbon solvent include hydrocarbon solvents such as n-pentane, n-hexane, heptane, octane, methylcyclopentane, isopentane, cyclopentane, cyclohexane, benzene and xylene.
Species or a combination of two or more can be used, but cyclohexane is preferred. As the organic alkali metal compound as a polymerization initiator, an organic lithium compound is preferable. As the organic lithium compound, an organic monolithium compound, an organic dilithium compound, and an organic polylithium compound are used. Specific examples of these include ethyl lithium, n-propyl lithium, isopropyl lithium, n
-Butyllithium, sec-butyllithium, isoprenyldilithium and the like, and are used in an amount of 0.02 to 0.2 parts by weight per 100 parts by weight of the monomer.

At this time, Lewis bases such as ethers and amines, such as diethyl ether, tetrahydrofuran, propyl ether, and the like, are used as regulators (vinylating agents) of the microstructure, that is, the vinyl bond content of the conjugated diene portion. Butyl ether, higher ethers, and ether derivatives of glycols such as ethylene glycol butyl ether, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol butyl ether, ethylene glycol dibutyl ether, and propylene glycol diethyl ether; tetramethylethylene diamine as an amine; Tertiary amines such as pyridine and tributylamine;
It is used with an inert hydrocarbon solvent in an amount of 0.02 to 0.2 parts by weight per 00 parts by weight.

The polymerization reaction is usually carried out at 20 to 120 ° C., preferably 30 to 100 ° C. Further, the polymerization may be carried out at a controlled temperature or at an elevated temperature without heat removal.

When a coupling agent is added to the thus obtained block copolymer living anion, a block copolymer having an extended polymer molecular weight can be obtained.
In addition, (a) during the production of the block copolymer, a coupling agent in an amount less than the equivalent is added, and a coupling reaction with the block copolymer, which is not coupled and the polymer molecular chain is not extended, is carried out by a coupling reaction. Can be obtained as a composition in which a block copolymer having an extended length is present at the same time, or each component may be separately prepared and mixed.

As the coupling agent at this time, for example, dibromomethane, dibromoethane, dibromopropane,
Dihalogenated alkanes such as methylene chloride, dichloroethane, dichloropropane and dichlorobutane; trihalogenated alkanes such as chloroform, trichloroethane, trichloropropane and tribromopropane; dichlorosilane; trichlorosilane; tetrachlorosilane;
Monomethyldichlorosilane, dimethyldichlorosilane,
Monoethyldichlorosilane, diethyldichlorosilane,
Monobutyldichlorosilane, dibutyldichlorosilane,
Silicon halide compounds such as monohexyldichlorosilane, dihexyldichlorosilane, dibromosilane, monomethyldibromosilane, and dimethyldibromosilane; tin halides such as tetrachlorotin, dichlorotin, dibromotin, and tetrabromotin; dimethyldichlorotin; methyltrichlorotin , Alkyltin halides such as butyltrichlorotin, divinylaromatic vinyl compounds such as divinylbenzene and divinylnaphthalene, and esters such as ethyl formate, ethyl acetate, butyl acetate, methyl propionate, phenyl acetate, ethyl benzoate and phenyl benzoate Among them, preferred are halogenated alkanes or silicon halide compounds. These coupling agents are used in a molar ratio of about 0.05 to 0.5 with respect to the organic alkali metal compound (preferably the organic lithium compound).

(A) The bond content of the aromatic vinyl compound in the block copolymer is controlled by the amount of the monomer supplied during the polymerization in each step, and the vinyl bond content of the conjugated diene, which is adjusted as necessary, is as follows: It is adjusted by varying the components of the micromodulator. The weight average molecular weight of (a) the block copolymer is adjusted by the amount of a polymerization initiator, for example, n-butyllithium. In the present invention, (a) the double bond of the conjugated diene portion of the block copolymer may be saturated by hydrogenation. The block copolymer (a) of the present invention can be used in the form of a veil, a re-emulsified latex, a blend with another polymer, or a pellet, crumb, or powder alone.

The (b) naphthenic or paraffinic process oil used in the present invention is generally a process oil having an aromatic content of 30% by weight or less in ring analysis. When an aromatic oil having an aromatic content exceeding 30% by weight is used, the compatibility of the asphalt composition is improved, but the physical properties such as a softening point are lowered, which is not preferable.

Next, (c) straight asphalt used in the present invention is obtained as a residue after subjecting asphalt base crude oil to atmospheric distillation and steam or vacuum distillation. Straight asphalt (a)
Since the block copolymer is easily dissolved, processing and handling are easy. (C) Straight asphalt has a penetration of 40 to 200. If the penetration is less than 40, the flexibility at low temperatures tends to be impaired, while if it exceeds 200, the abrasion resistance and the flow resistance tend to decrease.

The asphalt composition of the present invention contains the above components (a) to (c) as main components. The amount of the component (b) is 2 to 15 per 100 parts by weight of the component (a). Parts by weight, preferably 3 to 10 parts by weight. When the amount of the component (b) is less than 2 parts by weight, the binder properties are good, but the compatibility with asphalt is poor and storage stability is impaired. On the other hand, when the amount exceeds 15 parts by weight, the softening point and toughness are increased. -Low tenacity, high penetration, and poor binder properties.

The weight ratio of the total amount of the components (a) and (b) to the component (c) is 2/98 to 20/8.
0, preferably 3/97 to 15/85. If the weight ratio is less than 2/98, the asphalt modifying effect is not seen, the softening point is insufficient, and the penetration and toughness / tenacity are low. On the other hand, if it exceeds 20/80, the softening point is low. , The toughness tenacity is enough, but the dissolution time in asphalt becomes significantly longer, the compatibility becomes worse,
In addition, the melt viscosity of the composition becomes extremely high, making processing and handling difficult.

The asphalt composition of the present invention usually contains 1
It is manufactured by charging and mixing the above components (a) to (b) into (c) straight asphalt under stirring at 40 to 190 ° C. In addition, (a) component and (b)
The components may be kneaded in advance to form a uniform composition and then (c) added to straight asphalt,
You may put them separately.

The asphalt composition of the present invention includes:
If necessary, fillers such as silica, talc, and calcium carbonate, and additives such as a pigment, an antioxidant, a crosslinking agent, and a flame retardant can be blended. Also, for adjusting the hardness of asphalt, petroleum resin, rosin resin, terpene resin, alicyclic hydrocarbon resin, cumarone resin, phenolic resin, aromatic hydrocarbon resin, aliphatic hydrocarbon resin,
And these hydrogenated resins can be blended. Furthermore, when used for road pavement, it is also possible to add gravel or the like.

Further, the asphalt composition of the present invention includes:
Other thermoplastic elastomers and thermoplastic resins, for example, styrene-butadiene rubber latex, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, atactic polypropylene, 1,2-polybutadiene,
Alternatively, another polymer such as ethylene-propylene rubber can be used in combination. In this case, the component (a) and / or the component (b) of the present invention and the other polymer (thermoplastic elastomer and / or thermoplastic resin) are kneaded at an arbitrary ratio and then pelletized. Can also be used.

[0028]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the examples, parts and% are by weight unless otherwise specified. The various evaluations in the examples were obtained as follows.

Characteristic weight average molecular weight (Mw) of block copolymer GPC apparatus [Tosoh Co., Ltd., HLC-8020 type is used, and column is ZORBAX 1000 manufactured by DuPont.
S used 3) and converted to standard polystyrene. Bound styrene content was determined from the absorption intensity at 690 cm ^-1 using an infrared spectrometer (Perkin Elmer 1600).

Characteristic dissolution time of asphalt composition The dissolution time is determined by preparing a bitumen composition, collecting a small amount of the content during mixing, applying the content on a polyester (tetron) sheet and observing the content. The time was taken until no solid particles were observed. Toughness Tenacity "Pavement Test Method Handbook" (November 1988, published by The Japan Road Association) 3-5-17 The toughness tenacity test method was followed. Penetration, elongation, softening point Measured according to JIS K2207. Melt viscosity Measured at 140 ° C. using a B-type viscometer. Phase Separability The prepared asphalt composition was poured into a cylindrical container made of a 300 cc aluminum can, and was placed in an oven for 180 minutes.
At 72 ° C. for 72 hours under a nitrogen atmosphere, and then cooled at room temperature.
The aluminum can was divided into upper and lower parts in the middle, dissolved and stirred again in an oven, and the upper and lower softening points, penetration and melt viscosity were compared.

Example 1 Preparation of Block Copolymer After thoroughly replacing a 100-liter stainless steel polymerization vessel equipped with a jacket and a stirrer with nitrogen gas,
50 kg of cyclohexane and 3.0 kg of styrene were charged, and the contents were brought to 40 ° C. by passing warm water through the jacket.
Next, 16.0 g of sec-butyllithium was added to initiate polymerization. After the completion of the polymerization of styrene, while passing cold water through the jacket so that the temperature of the contents is 80 ℃,
7.0 kg of 1,3-butadiene were added slowly.
After the polymerization of 1,3-butadiene was completed, 4.4 g of dimethyldichlorosilane was added as a coupling agent,
Stir for 30 minutes. After the reaction, 1 ml of methanol was added, and the mixture was stirred for 10 minutes.
50 g of methylphenol (BHT) was added, and a paraffin-based process oil [PS-Idemitsu Kosan Co., Ltd.
32] was added. This polymerization solution was subjected to steam stripping, and the obtained water-containing polymer was pulverized into a crumb shape with a crusher, and then dried at 80 ° C. with hot air to obtain a styrene-butadiene block copolymer.

Preparation of Asphalt Composition 570 g of straight asphalt having a penetration of 70 (manufactured by Kyodo Sekiyu KK, 60/80) and the styrene-
30 g of a butadiene block copolymer was mixed with a stirrer (TK homomixer, 10,000 rpm, manufactured by Tokushu Kika Kogyo Co., Ltd.) while heating at 180 ° C. to prepare an asphalt composition. Table 1 shows the evaluation results of each characteristic.

Examples 2 to 4 and Comparative Examples 1 to 7 Examples 2 to 3 and Comparative Examples 1 to 6
-Butadiene, sec-butyllithium, except for changing the charged amount of dimethyldichlorosilane and the type and charged amount of process oil, in the same manner as in Example 1,
In Example 4, styrene, 1,3-butadiene, se
A block copolymer was obtained in the same manner as in Example 1 except that c-butyllithium, the type and amount of the process oil and the amount of the coupling agent were changed to 1,2-dibromoethane, and the same as in Example 1 To prepare an asphalt composition, and its performance was evaluated. In Comparative Example 7, an asphalt composition was prepared in the same manner as in Example 1 except that the oil of Example 1 was changed to an aromatic oil, and its performance was evaluated. The results are shown in Tables 1 and 2.

Example 5 After sufficiently replacing a 100-liter stainless steel polymerization vessel equipped with a jacket and a stirrer with nitrogen gas,
50 kg of cyclohexane and 1.5 kg of styrene were charged, and the contents were brought to 40 ° C. by passing warm water through the jacket.
Next, 8.2 g of sec-butyllithium was added to initiate polymerization. After the polymerization of styrene is completed, the content temperature is 8
While passing cold water through the jacket to reach 0 ° C,
7.0 kg of 3-butadiene were added slowly. 1,
After the completion of the polymerization of 3-butadiene, 1.5 kg of 2
A second round of styrene was added. After completion of the reaction, methanol 1
After stirring for 10 minutes, the content was taken out of the polymerization vessel, and 50 g of 2,6-di-t-butyl-4-methylphenol (BHT) as an antioxidant was added. 500 g of oil [PS-32, manufactured by Idemitsu Kosan Co., Ltd.] was added. This polymerization solution was subjected to steam stripping, and the obtained water-containing polymer was pulverized into a crumb shape with a crusher.
And dried with hot air to obtain a styrene-butadiene block copolymer. Next, an asphalt composition was prepared in the same manner as in Example 1, and each property was evaluated. Table 1 shows the results.

Example 6 In Example 6, the method of Example 5 was repeated, except that 1,3-butadiene was further added after the second reaction of styrene, and styrene, 1,3-butadiene and sec-butyllithium were charged. Except for changing the amount, a block copolymer was obtained in the same manner as in Example 5, an asphalt composition was prepared in the same manner as in Example 1, and the performance was evaluated. Table 1 shows the results
Shown in

From Table 1, it can be seen that the asphalt compositions of the present invention (Examples 1-6) have improved phase separation during high temperature storage,
Moreover, it can be seen that good binder physical properties are exhibited. On the other hand, Comparative Example 1 is an example in which the weight average molecular weight and the bound styrene content of the polystyrene block are lower than the lower limits, and the physical properties of the binder are inferior. Comparative Example 2 is an example in which the weight average molecular weight of the polystyrene block exceeds the upper limit, and the dissolution time is significantly increased, and the phase separation property is deteriorated. Comparative Example 3 is an example in which the weight average molecular weight of the polystyrene block and the component (a) is lower than the lower limit, and although the phase separation property is improved, the binder physical properties are inferior. Comparative Example 4 is an example in which the bound styrene content exceeds the upper limit, and the binder physical properties are inferior. Comparative Example 5 is an example in which the weight ratio of the component (b) to the component (a) exceeds the upper limit, and the phase separation property is deteriorated. Comparative Example 6 is an example in which the weight ratio of the component (b) to the component (a) is below the lower limit, and the physical properties of the binder are inferior. Comparative Example 7
The oil used is of an aromatic type and has a low softening point,
It can be seen that the physical properties of the binder are reduced.

Examples 7 to 8, Comparative Example 8 A block copolymer was obtained in the same manner as in Example 1 except that the charged amount of sec-butyllithium and the coupling agent were changed to tetrachlorosilane. The asphalt composition was prepared in the same manner as described above, and its performance was evaluated. Table 3 shows the results. Examples 7 and 8 are examples in which a tetrafunctional coupling agent is used, and the compatibility is improved. On the other hand, Comparative Example 8 is an example in which a tetrafunctional coupling agent is used and the weight average molecular weight of the component (A) exceeds the upper limit, and the dissolution time is significantly increased, and the phase separation property is also poor.

Comparative Examples 9 to 10 Asphalt was prepared in the same manner as in Example 1 except that the amount of addition to the asphalt was changed using the block copolymer of Example 1, and its performance was evaluated. Table 3 shows the results. As is clear from Table 3, when the amount of the block copolymer added is less than the range specified in the present invention (Comparative Example 8), the physical properties of the binder are inferior. On the other hand, when it is too large (Comparative Example 9), the physical properties are good. However, it takes a long time to dissolve, and the phase separation property deteriorates.

The oils used in Tables 1 to 3 are as follows. P (paraffin type); Idemitsu Kosan Co., Ltd., PS-32N (naphthenic type); Shell Japan Co., Ltd., Shellflex 371JYA (aromatic type); Shell Japan Co., Ltd., Deuterex 729UK

[0040]

[Table 1]

[0041]

[Table 2]

[0042]

[Table 3]

[0043]

The asphalt composition of the present invention is excellent in high-temperature storage stability and has a good balance with binder properties, and can be suitably used for road applications, waterproof sheets and the like.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masaru Oda 34-J.

Claims (1)

[Claims] 1. (a) General formulas: ABA ', AB-
A'-B or (AB) nX (where X is a residue of a coupling agent, n is an integer of 2 to 6, and A to A 'are those having a weight average molecular weight of A polymer block mainly composed of an aromatic vinyl compound, B is a polymer block mainly composed of a conjugated diene, the weight average molecular weight of the entire block copolymer is 100,000 to 400,000, and the total bond content of A and A '. Is 20 to 45% by weight) or a mixture thereof, (b) a naphthenic and / or paraffinic process oil, and (c) a straight asphalt having a penetration of 40 to 200. As a main component, the component (b) is 2 to 15 parts by weight with respect to 100 parts by weight of the component (a), and the weight ratio of the total amount of the components (a) and (b) to the component (c) is 2/98. ~ 20/80
An asphalt composition comprising: