JP2003055560A - Asphalt, and block copolymer for modifying asphalt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an asphalt composition excellent in a high temperature preservation stability and low temperature characteristics, and also excellent in balance of each of the characteristics. SOLUTION: [1] The asphalt composition consists of (1) 0.5-50 pts.wt. block copolymer consisting of a polymer block consisting mainly of at least 2 vinylaromatic hydrocarbons and a copolymer block consisting of at least one isoprene and 1,3-butadiene and/or at least one isoprene, 1,3-butadiene and a vinylaromatic hydrocarbon, in which (a) the content of the vinyl aromatic hydrocarbon in the bock copolymer is <60 wt.%, (b) the content of the total of the isoprene and 1,3-butadiene is >40 wt.% and <=95 wt.%, (c) the weight ratio of the isoprene to 1,3-butadiene is in the range of (90/10)-(15/85), (d) the amount of vinyl bonding is <40 wt.% and (e) the MFR (condition G) is 0.1-100 g/10 min, and (2) 100 pts.wt. asphalt. [2] The bock copolymer is used for the new asphalt.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a block copolymer comprising a specific vinyl aromatic hydrocarbon, isoprene and 1,3-butadiene, and high temperature storage stability using the block copolymer as a modifier ( The present invention relates to an asphalt composition having excellent phase separation stability) and low temperature characteristics.

[0002]

2. Description of the Related Art Conventionally, asphalt compositions have been widely used for applications such as road paving, waterproof sheets, sound insulation sheets, and roofing. At that time, many attempts have been made to improve the properties of asphalt by adding various polymers. As specific examples of the polymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, rubber latex, block copolymer composed of conjugated diene and vinyl aromatic hydrocarbon, and the like are used. For example, Japanese Patent Publication No. 47-17319 discloses an asphalt composition using a block copolymer of a vinyl aromatic compound and a conjugated diene compound.

However, in recent years, due to the increase in the number of vehicles passing by the road or the increase in speed, excellent strength,
The demand for wear-resistant asphalt mixtures and, in addition, asphalt mixtures with high open particle size for the purpose of improving drainage performance at these high speeds and reducing noise while maintaining strength and wear resistance are increasing. . Therefore, higher softening point, bending stress, mechanical strength such as aggregate grasping force are required, and it has been attempted to improve by increasing the molecular weight of the block copolymer, for example. The method has problems such as insufficient storage stability during high-temperature storage, high melt viscosity, and poor workability during road pavement, and conventional techniques have not yet yielded satisfactory results. On the other hand, Japanese Patent Laid-Open No. 3-259955 discloses a vibration damping composition comprising asphalt and a block copolymer composed of a block composed of a vinyl aromatic monomer and a block composed of isoprene or an isoprene-butadiene mixture. .

[0004]

Under such circumstances, a composition of a block copolymer composed of a vinyl aromatic hydrocarbon and a conjugated diene and asphalt has excellent high temperature storage stability and low temperature characteristics, and is used for road paving. A method for providing a composition suitable for roofing / waterproof sheet applications, sealant applications, and the like has been desired.

[0005]

DISCLOSURE OF THE INVENTION The present inventors have found a block copolymer composed of a vinyl aromatic hydrocarbon and a conjugated diene, which is used for road pavement applications, roofing / waterproof sheet applications, sealant applications and the like. As a result of diligent studies on the improvement of the properties of the composition with asphalt, in an asphalt composition consisting of a block copolymer consisting of asphalt, vinyl aromatic hydrocarbons and conjugated dienes, using isoprene and 1,3-butadiene as conjugated dienes, Moreover, it was found that an asphalt composition excellent in high temperature storage stability and low temperature characteristics can be obtained by setting the ratio to a specific range and a specific vinyl bond amount at the same time,
The present invention has been completed.

That is, the present invention is: (1) at least two polymer blocks mainly composed of vinyl aromatic hydrocarbons, and at least one copolymer block composed of isoprene and 1,3-butadiene and / or isoprene A block copolymer having at least one copolymer block composed of 1,3-butadiene and vinyl aromatic hydrocarbon, wherein (a) the vinyl aromatic hydrocarbon content of the block copolymer is at least 5% by weight. weight%
Less than (b) the total content of isoprene and 1,3-butadiene is more than 40% by weight and 95% by weight or less, and (c) the weight ratio of isoprene and 1,3-butadiene in the block copolymer is 90/10 to 15/85, (d) vinyl bond content is less than 40% by weight, and (e) MFR.
0.5 to 50 parts by weight of a block copolymer having (G condition) of 0.1 to 100 g / 10 minutes, and (2) asphalt 1
And 100 parts by weight of the asphalt composition.
Further, the asphalt composition according to the above 1) relates to an asphalt composition suitable for any of road pavement applications, roofing / waterproof sheet applications, and sealant applications. Further, (1) at least two polymer blocks containing vinyl aromatic hydrocarbon as a main component, and at least one copolymer block containing isoprene and 1,3-butadiene and / or isoprene, 1,3-butadiene and vinyl. A block copolymer having at least one copolymer block comprising an aromatic hydrocarbon, wherein (a) the vinyl aromatic hydrocarbon content of the block copolymer is from 5% by weight to 60% by weight.
Less than (b) the total content of isoprene and 1,3-butadiene is more than 40% by weight and 95% by weight or less, and (c) the weight ratio of isoprene and 1,3-butadiene in the block copolymer is 90/10 to 15/85, (d) vinyl bond content is less than 40% by weight, and (e) MFR.
It relates to a block copolymer for asphalt modification in which (G condition) is 0.1 to 100 g / 10 minutes. In addition, in the block copolymer for asphalt modification described, it is used for road paving, roofing and waterproof sheets,
The present invention relates to an asphalt-modifying block copolymer suitable for any of sealant applications.

The present invention will be described in detail below. The block copolymer of the component (1) used in the present invention is obtained by polymerizing vinyl aromatic hydrocarbon with isoprene and 1,3-butadiene in an organic solvent using an organic lithium compound as an initiator. As the hydrocarbon solvent used for producing the block copolymer, butane, pentane, hexane, isopentane, heptane, octane, isooctane and other aliphatic hydrocarbons; cyclopentane, methylcyclopentane,
Alicyclic hydrocarbons such as cyclohexane, methylcyclohexane and ethylcyclohexane; and aromatic hydrocarbons such as benzene, toluene, ethylbenzene and xylene may be used, and these may be used alone or in admixture of two or more. .

The vinyl aromatic hydrocarbon used in the block copolymer is styrene, o-methylstyrene, p-
Methyl styrene, p-tert-butyl styrene, 1,
There are 3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene, 1,1-diphenylethylene and the like, but styrene is particularly common. These may be used alone or in combination of two or more. The vinyl aromatic hydrocarbon content (a) of the block copolymer is 5% by weight or more and less than 60% by weight, preferably 10 to 50% by weight, more preferably 15 to 45% by weight. The combined content (b) of isoprene and 1,3-butadiene is more than 40% by weight and 95% by weight or less, preferably 50 to 90% by weight, more preferably 55 to 85% by weight. When the content (b) of vinyl aromatic hydrocarbon is outside the above range, the performance balance of asphalt is poor, which is not preferable.

The block copolymer isoprene and 1,3-
The weight ratio (c) of butadiene is 90/10 to 15/85, preferably 85/15 to 20/80, more preferably 80.
/ 20 to 25/75. Particularly, in order to obtain an asphalt composition excellent in low temperature characteristics, isoprene and 1,3
The weight ratio (c) of butadiene is 60/40 to 15/85,
Preferably 55/45 to 20/80, more preferably 5
It is recommended to be 0/50 to 25/75. Weight ratio of block copolymer isoprene and 1,3-butadiene
When (c) is out of the above range, the storage stability at high temperature is poor, and when the asphalt composition is stored at high temperature for a long time, the difference in softening point between the upper layer portion and the lower layer portion becomes large, which is not preferable. The vinyl bond content (d) of the block copolymer used in the present invention is less than 40% by weight, preferably 35% by weight or less, and more preferably 30 to 10% by weight. here,
The vinyl bond content (d) means 1,2-
Of the butadiene and isoprene incorporated in the form of bonds, 3,4-bonds and 1,4-bonds, 1,2
-Percentage of those incorporated by bonds and 3,4-bonds. When the vinyl bond amount (d) is 40% by weight or more, the low temperature properties of the asphalt composition are inferior, which is not preferable.

The block copolymer used in the present invention is a copolymer block composed of isoprene and 1,3-butadiene in the block copolymer and / or at least one isoprene and 1,3-butadiene. The main dispersion peak of tan δ obtained by viscoelasticity measurement based on a copolymer block composed of vinyl aromatic hydrocarbon is less than 0 ° C.,
It is recommended that the temperature is preferably lower than -20 ° C, more preferably lower than -25 ° C in order to obtain an asphalt composition having good low temperature properties. In the present invention, in order to obtain an asphalt composition having further excellent high-temperature storage stability, the ratio of vinyl aromatic hydrocarbon polymer blocks incorporated in the block copolymer (referred to as the vinyl aromatic hydrocarbon block ratio) is determined. It is recommended to adjust to 50 to 97% by weight, preferably 60 to 95% by weight, more preferably 70 to 92% by weight.

The block ratio of the vinyl aromatic hydrocarbon incorporated in the block copolymer is measured by oxidative decomposition of the block copolymer with tertiary butyl hydroperoxide using osmium tetroxide as a catalyst [I. M. KOLTHOFF, et al. J. Pol
ym. Sci. 1,429 (1946))
Using the vinyl aromatic hydrocarbon polymer block component (excluding the vinyl aromatic hydrocarbon polymer component having an average degree of polymerization of about 30 or less) obtained by it can.

[Equation 1]

The block ratio of the vinyl aromatic hydrocarbon is 1 when the vinyl aromatic hydrocarbon, isoprene and 1,3-butadiene are copolymerized in the process of copolymerizing the vinyl aromatic hydrocarbon, isoprene and 1,3-butadiene during the production of the block copolymer. It can be controlled by changing the weight, weight ratio, polymerization reactivity ratio, etc. of 3,3-butadiene. As a specific method, a mixture of vinyl aromatic hydrocarbon, isoprene and 1,3-butadiene is continuously supplied to a polymerization system to polymerize, and / or a polar compound or a randomizing agent is used to vinylate. A method such as copolymerizing an aromatic hydrocarbon, isoprene and 1,3-butadiene can be adopted. Examples of polar compounds and randomizing agents include ethers such as tetrahydrofuran, diethylene glycol dimethyl ether, and diethylene glycol dibutyl ether; triethylamine,
Examples include amines such as tetramethylethylenediamine; thioethers, phosphines, phosphoramides, alkylbenzene sulfonates, alkoxides of potassium and sodium, and the like.

The block copolymer of the present invention comprises at least 2
One vinyl aromatic hydrocarbon-based polymer block, at least one isoprene and 1,3-butadiene copolymer block and / or at least one isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon A block copolymer having a copolymer block consisting of, for example, one represented by the following general formula (1) can be given. (A) A- (BA) _n , (b) A- (BA) _n- B, (c) B- (AB) _{n + 1} (1) A chain block copolymer or the general formula (2); (d) [(AB) _k ] _{m + 1} -X, (e) [(AB) _k -A] _{m + 1} -X, (F) [(B-A) _k ] _{m + 1} -X, (g) [(B-A) _k -B] _{m + 1} -X ... (2) It is a polymer or a radial block copolymer. (However, in the above formulas (1) and (2), A represents a polymer block mainly composed of vinyl aromatic hydrocarbon, and B represents a copolymer block composed of isoprene and 1,3-butadiene and / or isoprene. And 1,3-
1 shows a copolymer block composed of butadiene and vinyl aromatic hydrocarbon. X is, for example, silicon tetrachloride, tin tetrachloride,
The residue of the coupling agent such as epoxidized soybean oil, polyhalogenated hydrocarbon, carboxylic acid ester, and polyvinyl compound or the residue of the initiator such as polyfunctional organolithium compound is shown. n, k, and m are integers of 1 or more, generally 1 to 5. )

In the above formulas (1) and (2), the block A is a vinyl aromatic hydrocarbon homopolymer and / or a vinyl aromatic hydrocarbon homopolymer containing 70% by weight or more of a vinyl aromatic hydrocarbon. Is a copolymer block of 1,3-butadiene and / or isoprene, and block B is a copolymer block and / or isoprene composed of isoprene and 1,3-butadiene having a vinyl aromatic hydrocarbon content of less than 70% by weight. And a copolymer block composed of 1,3-butadiene and vinyl aromatic hydrocarbon. In the present invention, the B block may coexist with a 1,3-butadiene homopolymer portion and / or an isoprene homopolymer portion. Further, the block copolymer used in the present invention includes at least one isoprene and 1,3-isoprene defined in the present invention.
Copolymer block consisting of butadiene and / or having at least one isoprene and a copolymer block consisting of 1,3-butadiene and vinyl aromatic hydrocarbon, and isoprene and 1,3-butadiene in the block copolymer If the weight ratio (d) of the above satisfies the range of the present invention, even if the 1,3-butadiene homopolymer block and / or the isoprene homopolymer block coexist as the B block in the block copolymer. good.

The molecular weight of the block copolymer used in the present invention is measured by GPC so that the peak molecular weight is 30,000 to 1,000,000, preferably 50,000 to 100 in terms of standard polystyrene.
It is 800,000, and more preferably 70,000 to 500,000. If the molecular weight is less than 30,000, the softening point and mechanical strength of the asphalt composition will be poor, and if it exceeds 1 million, the solubility in asphalt will be poor, such being undesirable. In particular, in terms of solubility in asphalt and storage stability at high temperatures, MFR of block copolymers
(G condition: temperature 200 ° C., load 5 kg) (e) is 0.1 to 100 g / 10 minutes from the viewpoint of moldability and appearance of the molded product,
Preferably 0.5 to 50 g / 10 minutes, more preferably 1
~ 30 g / 10 minutes. The block copolymer used in the present invention may be hydrogenated if necessary.

In the asphalt composition of the present invention, a block copolymer (1-A) consisting of one vinyl aromatic hydrocarbon-based polymer block, one isoprene and 1,3-butadiene is used. Copolymer block and / or block copolymer having one copolymer of isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon
0% by weight, preferably 20-80% by weight (1-B) At least two vinyl aromatic hydrocarbon-based polymer blocks and at least one isoprene and 1,3-butadiene copolymer block And / or 90 to 10% by weight, preferably 80 to 20% by weight, of a block copolymer having a copolymer block of at least one isoprene, 1,3-butadiene and vinyl aromatic hydrocarbon. Is recommended for obtaining an asphalt composition having a better balance between softening point and high temperature storage stability.

In the block copolymer of the present invention, 2- [1- (2-hydroxy-3,5-di-t-
Pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate, 2-t-butyl-6- (3-
t-butyl-2-hydroxy-5-methylbenzyl)-
At least one stabilizer selected from 4-methylphenyl acrylate and 2,4-bis [(octylthio) methyl] -o-cresol is used in an amount of 0.05 to 3 parts by weight, preferably 100 parts by weight of the block copolymer. By adding 0.1 to 2 parts by weight, a further thermal stability effect can be obtained during dissolution at high temperature, storage and construction. The block copolymer of the present invention includes n-octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate and tetrakis [methylene-3-.
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] methane, 1,3,5-trimethyl-
2,4,6-Tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di- t
-Butylanilino) -1,3,5-triazine and the like at least one phenol-based stabilizer block copolymer 1
0.05-3 parts by weight with respect to 00 parts by weight; and Tris-
(Nonylphenyl) phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octylphosphite, 2-[[2,4,8,10-tetrakis (1,1-dimethylethyl) dibenzo] [D, f] [1,
3,2] Dioxaphosphine-6-yl] oxy] -N, N-bis [2-[[2,4,8,10-tetrakis (1,1-dimethylethyl) dibenzo [d, f]
[1,3,2] Dioxaphosphine-6-yl]
Oxy] -ethyl] -ethanamine, tris (2,4-
At least one of organic phosphate-based and organic phosphite-based stabilizers such as di-t-butylphenyl) phosphite
0.05 to 100 parts by weight of the block copolymer.
3 parts by weight can be added.

Next, the asphalt of the component (2) used in the present invention is obtained as a by-product (petroleum asphalt) during petroleum refining, or obtained as a natural product (natural asphalt), or these and petroleum. There can be mentioned a mixture and the like, the main component of which is called bitumen. Specifically, straight asphalt, semi-blown asphalt, blown asphalt, tar, pitch, cutback asphalt added with oil, asphalt emulsion and the like can be used. These may be mixed and used. The asphalt preferred in the present invention has a penetration of 30 to 3
00, preferably 40 to 200, more preferably 45 to
It is 150 straight asphalt.

In the asphalt composition of the present invention, the blending ratio of the block copolymer is 0.5 to 50 parts by weight, preferably 1 to 30 parts by weight, more preferably 3 to 20 parts by weight based on 100 parts by weight of the asphalt. Is. Various additives may be added to the asphalt composition of the present invention as required. These additives include, for example, inorganic fillers such as calcium carbonate, magnesium carbonate, talc, silica, alumina, titanium oxide, glass fibers, glass beads; organic reinforcing agents such as organic fibers and coumarone indene resin; Cross-linking agents such as oxides and inorganic peroxides; pigments such as titanium white, carbon black and iron oxide; dyes, flame retardants, antioxidants, ultraviolet absorbers, antistatic agents,
Lubricants, paraffin-based process oils, naphthene-based process oils, aromatic process oils, paraffins, organic polysiloxanes, mineral oils and other softeners / plasticizers;
Tackifying resin such as coumarone indene resin and terpene resin; polyolefin resin such as atactic polypropylene and ethylene-ethyl acrylate copolymer; low molecular weight vinyl aromatic thermoplastic resin, natural rubber, polyisoprene rubber, ethylene- Synthetic rubbers such as propylene rubber, chloroprene rubber, acrylic rubber, isoprene-isobutylene rubber, and styrene-butadiene block copolymers other than the present invention, styrene-isoprene block copolymers; vulcanizing agents such as sulfur, vulcanization Examples include auxiliaries, other bulking agents, and mixtures thereof. In particular, when the asphalt composition of the present invention is used for road paving, it is usually used as a mixture with aggregates such as crushed stone, sand and slag, which are mineral substances.

The method of mixing the asphalt composition of the present invention is not particularly limited, and if necessary, the above-mentioned various additives may be heated and melt-kneaded with, for example, a heat-melting pot, a kneader, a Banbury mixer or an extruder. Can be prepared by

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the present invention will be described below, but these do not limit the scope of the present invention. Table 1 shows the block copolymers used in Examples and Comparative Examples. The block copolymer was polymerized by using n-butyllithium as an initiator in a cyclohexane solvent and adding the monomers in the order and amount described in the polymer structure column of Table 2. The vinyl bond amount was adjusted by changing the amount of tetramethylethylenediamine used. After completion of the polymerization, methanol was added to stop the polymerization reaction, and then the amount of the stabilizer shown in the remarks column of Table 1 was added and the solvent was distilled off to recover the block copolymer.

The characteristics of the block copolymer and the characteristics of the asphalt composition were measured as follows. Characteristics of Block Copolymer (i) Styrene Content Using an ultraviolet spectrophotometer (Hitachi UV200), 262
It was calculated from the absorption intensity at nm. (ii) Vinyl bond infrared spectrophotometer (Model 171 made by Parking Elmer
0) and calculated by the Hampton method. (iii) MFR G condition: Measured at a temperature of 200 ° C. and a load of 5 kg.

Characteristics of Asphalt Composition (i) Softening Point (Ring & Ball Method) In accordance with JIS-K 2207, a sample is filled in a prescribed ring and supported horizontally in a glycerin solution, and the center of the sample is 3.5.
When a g ball was placed and the liquid temperature was raised at a rate of 5 ° C./min, the temperature at which the sample touched the bottom plate of the ring base was measured by the weight of the ball. (ii) Melt viscosity was measured with a Brookfield viscometer at 180 ° C. (iii) Penetration degree According to JIS-K 2207, the length at which a specified needle enters a sample kept at 25 ° C in a constant temperature water bath for 5 seconds was measured. (iv) Elongation According to JIS-K 2207, the sample is poured into a frame,
After forming the specified shape, the temperature was kept at 4 ° C. in a constant temperature water bath, and when the sample was pulled at a speed of 5 cm / min, the distance that the sample extended before it was cut was measured. (v) High-temperature storage stability (separation characteristics) Immediately after the asphalt composition was prepared, the inner diameter was 50 mm and the height was 13
The asphalt composition was poured into a 0 mm aluminum can up to the upper limit of the aluminum can, put in an oven at 180 ° C., taken out after 24 hours and naturally cooled. Next, the asphalt composition cooled to room temperature is 4 cm from the lower end and 4 cm from the upper end.
The asphalt composition was sampled and the softening points of the upper and lower layers were measured, and the difference in the softening points was used as a measure of high temperature storage stability.

[0024]

Examples 1 and 2 and Comparative Examples 1 to 4 The following tests were conducted according to the formulations shown in Table 2. 400 g of straight asphalt 60-80 (manufactured by Nippon Oil Co., Ltd.) is put into a 750 ml metal can, and the metal can is sufficiently immersed in an oil bath at 180 ° C. Next, a predetermined amount of the block copolymer is added little by little into the molten asphalt while stirring. 90 at the rotation speed of 5000 rpm after complete feeding
The asphalt composition was prepared by stirring for 1 minute. The characteristics are shown in Table 2. As is clear from Table 2, the asphalt composition of the present invention showed excellent high temperature storage stability and low temperature characteristics.

[0025]

Examples 3 and 4 Polymer 7 was used, and the compounding amount was 5
An asphalt composition was prepared in the same manner as in Example 1 except that parts by weight were used (Example 3). Further, an asphalt composition was prepared in the same manner as in Example 1 except that Polymer 8 was used and the compounding amount was 10 parts by weight (Example 4). The asphalt compositions of Examples 3 and 4 were excellent in high-temperature storage stability and low-temperature characteristics, and were well-balanced physical properties.

[0026]

[Table 1]

(Note 1) The following compounds were used as the coupling agent. Polymers 1 to 6: dibromomethane, Polymer 7: ethyl benzoate. (Note 2) The following stabilizers were added to each polymer. The amount of the stabilizer added is the amount added with respect to 100 parts by weight of the block copolymer. Polymer 1 to 6: A / D / E = 0.5 / 0.2 / 0.1 Polymer 7: A / B / C = 0.1 / 0.4 / 0.1 Polymer 8: A / C / F = 0.3 / 0.3 / 0.5 <Type of stabilizer> Stabilizer A: 2- [1- (2-hydroxy-3,5-di-
t-pentylphenyl) ethyl] -4,6-di-t-pentylphenyl acrylate stabilizer B: 2-t-butyl-6- (3-t-butyl-2)
-Hydroxy-5-methylbenzyl) -4-methylphenylacrylate stabilizer C: 2,4-bis [(octylthio) methyl]-
o-Cresol stabilizer D: n-octadecyl 3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate stabilizer E: tetrakis [methylene-3- (3,5-di-
t-butyl-4-hydroxyphenyl) propionate] methane stabilizer F: tris- (nonylphenyl) phosphite

[0028]

[Table 2]

[0029]

Industrial Applicability The present invention provides an asphalt composition which is excellent in storage stability at high temperature and low temperature characteristics and has a good balance of each asphalt characteristic. The asphalt composition of the present invention can be used for road pavement applications, roofing / waterproof sheet applications, sealant applications and the like.

Continued front page    F-term (reference) 2D051 AA01 AG01 AG03 AG18 EA06                 4J002 AG001 BP012 FD01 FD02                       FD09 FD14 FD34 GJ02 GL00

Claims (4)

[Claims] (1) At least two polymer blocks mainly composed of vinyl aromatic hydrocarbons, at least one copolymer block composed of isoprene and 1,3-butadiene, and / or isoprene and 1,3- A block copolymer having at least one copolymer block composed of butadiene and vinyl aromatic hydrocarbon, wherein (a) the vinyl aromatic hydrocarbon content of the block copolymer is 5% by weight or more and less than 60% by weight, (b) The total content of isoprene and 1,3-butadiene is more than 40% by weight and 95% by weight or less, and (c) isoprene and 1,3-butadiene in the block copolymer are included.
The weight ratio of butadiene is in the range of 90/10 to 15/85, (d) the vinyl bond content is less than 40% by weight, and
(e) 0.5 to 50 parts by weight of a block copolymer having an MFR (G condition) of 0.1 to 100 g / 10 minutes, and (2) 100 parts by weight of asphalt, an asphalt composition. object. 2. The asphalt composition according to claim 1, which is suitable for any of road pavement applications, roofing / waterproof sheet applications, and sealant applications. 3. (1) At least two polymer blocks mainly composed of vinyl aromatic hydrocarbon, at least one copolymer block composed of isoprene and 1,3-butadiene and / or isoprene and 1,3- A block copolymer having at least one copolymer block composed of butadiene and vinyl aromatic hydrocarbon, wherein (a) the vinyl aromatic hydrocarbon content of the block copolymer is 5% by weight or more and less than 60% by weight, (b) The total content of isoprene and 1,3-butadiene is more than 40% by weight and 95% by weight or less, and (c) isoprene and 1,3-butadiene in the block copolymer are included.
The weight ratio of butadiene is in the range of 90/10 to 15/85, (d) the vinyl bond content is less than 40% by weight, and
(e) A block copolymer for asphalt modification, which has an MFR (G condition) of 0.1 to 100 g / 10 minutes. 4. The block copolymer for asphalt modification according to claim 3, which is used for road paving and roofing.
A block copolymer for asphalt modification, which is suitable for use as a waterproof sheet or as a sealant.