JPH08225711A - Asphalt composition - Google Patents

Abstract

PURPOSE: To obtain an asphalt composition excellent in phase separating property at high temperatures, having a short dissolving time, excellent in storage stability and aggregate holding property, improved in processability because of low melting viscosity, well balanced in physical properties after execution and capable of using for paving of road, waterproof sheets, etc. CONSTITUTION: This asphalt composition is obtained by blending (a) a block copolymer expressed by the general formula (I) (A1 -B1 )nX and/or (A1 -B1 -A5 )nX, (b) a block copolymer expressed by the general formula (II) A2 -B2 and/or A2 -B2 -A6 , (c) a block copolymer expressed by the general formula (III) (A3 -B3 )nY and/or (A3 -B3 -A7 )nY, (d) a block copolymer expressed by the general formula (IV) A4 -B4 -A8 and/or A4 -B4 -A8 -B5 [in these general formulas (I) to (IV), A4 to A8 are each a polymer block consisting essentially of an aromatic vinyl compound; B1 to B5 each exhibits a polymer block consisting essentially of a conjugated diene] in specific ratios with (e) straight asphalt having 40-150 rate of penetration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an asphalt composition, and more specifically, to a straight asphalt compounded with a block copolymer of an aromatic vinyl compound having a specific structure and a conjugated diene, which can be stored at a high temperature. Excellent phase separation,
The present invention also relates to an asphalt composition having excellent dissolution time, storage stability, aggregate grasping property, low melt viscosity, and improved processability.

[0002]

2. Description of the Related Art Conventionally, asphalt is inexpensive and easily available, and is used for road paving, waterproof sheets, soundproof sheets,
Widely used in applications such as damping materials. However, since asphalt is inferior in softening point and penetration,
Attempts have been made to improve these properties to meet higher requirements. For example, the addition of various polymers has been attempted 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, it has been attempted to modify the asphalt by adding a block copolymer of an aromatic vinyl compound and a conjugated diene (SB block copolymer). For example, various asphalt compositions to which a block copolymer having a specific structure is added have been proposed for the purpose of improving various physical properties of asphalt. That is, JP-B-47-17319 discloses the use of an A-B-A type linear block copolymer, and JP-B-49-17007 discloses an A-B-A-B type linear block copolymer. The use of
JP-B-59-36949 discloses the use of a radial block copolymer represented by (A-B)nX type, and JP-A-5-27957 discloses an A-B-A type linear block copolymer. The combined use of (A-B)nX type radial block copolymer is disclosed. However, in these disclosed examples, although the softening point of asphalt and the binder physical properties such as toughness and tenacity are considerably improved,
Storage stability is not always sufficient, such as storage stability at high temperatures and deterioration of physical properties caused by phase separation or polymer decomposition that occurs during transportation.

For this reason, it has been generally practiced to improve the physical properties of these by adding an aromatic oil and crosslinking by adding sulfur or a peroxide. For example, the journal
Of Institute of Petroleum (Journa
l of Institute of Petroleum) Vol. 59, p. 566 (1
The use of aromatic oils in 973) is described in US Pat.
No. 6,363,59 and No. 4,053,176 use a peroxide, Japanese Patent Publication No. 57-24385 discloses a sulfur, and Japanese Patent Publication No. 1-13743 discloses a polysulfide having a specific structure. 3-50103
Japanese Patent No. 5 discloses the combined use of sulfur, a vulcanizing agent, and a sulfur donor vulcanization accelerator.

However, although the addition of the aromatic oil is effective in improving the high temperature storage stability,
The flow resistance and wear resistance after construction will decrease, and problems such as rutting will occur. Further, although crosslinking with sulfur or peroxide is effective for storage stability, it causes a problem that the dissolution time of the asphalt composition becomes extremely high and processability is impaired. Further, the polysulfide having a specific structure described in the above-mentioned patent is not sufficient in the diblock copolymer as a cross-linking effect as a result of cross-linking, but it is not sufficient and a peculiar offensive odor is obtained. Therefore, there is a problem in practical use. Further, when the above polysulfide is applied to a triblock copolymer, there arises a problem that the melt viscosity becomes extremely high and the processability is impaired. As described above, an attempt to modify the asphalt by using the block copolymer and the additive having a specific structure has not been yet satisfactory, and high temperature storage stability, dissolution time, binder physical properties, At present, no modifier has been found that satisfies the balance of workability and physical properties after construction, and further improvement is desired.

[0006]

The present invention has been made against the background of the above-mentioned problems of the prior art. In addition to being excellent in phase separation property at high temperature, the dissolution time is short, storage stability, and grasping of aggregates. It is an object of the present invention to provide an asphalt composition which is excellent in properties, has a low melt viscosity, has improved processability, and has a well-balanced physical property after construction and which can be used for road paving, waterproof sheets and the like.

[0007]

[In the general formulas (I) to (II), A ₁ , A ₂ , A ₅ and A ₆ are polymer blocks mainly composed of an aromatic vinyl compound having a weight average molecular weight of 5,000 to 20,000, B ₁ , B ₂ is a polymer block mainly composed of a conjugated diene, A ₁ -B ₁ , A ₁ -B ₁ -A ₅ , A ₂ -B ₂ and A ₂ -B ₂ -A ₆ are weight average molecular weights of 10,000- 60, X is a residue of a tin-based coupling agent and/or a tin-based terminal treatment agent and/or an ester-based coupling agent, n represents an integer of 1 to 6, and A ₁ and A ₅ , A ₂ and The total bond content of A ₆ is 20 to 70% by weight, and the vinyl bond content of the conjugated diene portion of B ₁ and B ₂ is 40 to 70%. In the general formulas (III) to (IV), A ₃ , A ₄ , A ₇ , and A ₈ are polymer blocks mainly composed of an aromatic vinyl compound having a weight average molecular weight of 9,000 to 20,000, and B ₃ , B ₄ and B ₅ are polymer blocks mainly composed of a conjugated diene, A ₃ -B ₃ and A ₃ -B ₃ -A ₇ are weight average molecular weights of 50,000 to 100,000 and A ₄ -B ₄ -A. _{8, a 4 -B 4 -A 8} -B 5 weight average molecular weight 100,000 to 200,000, Y is the residue of a tin-based and / or ester-based coupling agent other than, n represents an integer from 1 to 6 The total bond content of A ₃ and A ₇ , A ₄ and A ₈ is 20 to 45% by weight, and the vinyl bond content of B ₃ , B ₄ +B ₅ is 40 to 70%. ]

(E) Weight ratio of (a) component and (c) component or (d) component, (b) component and (c) component or (d) component, with straight asphalt having a penetration of 40 to 150 as the main component Is 5 to 50/95 to 50, and the weight ratio of the total amount of the component (a) or the component (b) and the component (c) or the component (d) to the component (e) is 2 to 20/98 to 80. And an asphalt composition characterized by the above.

The component (a) used in the present invention is a polymer block A ₁ or A containing an aromatic vinyl compound as a main component.
₅ and a polymer block B ₁ mainly composed of a conjugated diene,
(A ₁ -B ₁₎ nX and / or (A ₁ -B ₁ -A
₅ ) The component (b) arranged like nX is composed of polymer blocks A ₂ and A ₆ mainly containing an aromatic vinyl compound and polymer block B ₂ mainly containing a conjugated diene as A ₂ -B ₂ and/or A ₂ -B ₂ -A ₆ arranged block copolymer or a mixture thereof.

Further, the component (c) used in the present invention is a polymer block A mainly composed of an aromatic vinyl compound.
₃ and A ₇ and the polymer block B ₃ mainly composed of a conjugated diene are (A ₃ −B ₃ )nY and/or (A ₃ −).
B ₃ -A ₇₎ ordered, and (d) component as nY is the polymer block A mainly comprising an aromatic vinyl compound
₄ and A ₈ and polymer blocks B ₄ and B ₅ mainly containing a conjugated diene are arranged as A ₄ -B ₄ -A ₈ and/or A ₄ -B ₄ -A ₈ -B ₅ . It is a block copolymer or a mixture thereof.

In the general formulas (I) to (IV), polymer blocks A _{1 to} A ₈ are polymer blocks containing an aromatic vinyl compound as a main component and copolymerized with less than 50% by weight of a conjugated diene. May be In addition, general formulas (I) to (IV)
Among them, the polymer blocks B _{1 to} B ₅ are polymer blocks having a conjugated diene as a main component, and a conjugated diene homopolymer,
Alternatively, it is a copolymer block of a conjugated diene containing 50% by weight or more of a conjugated diene and an aromatic vinyl compound.
The aromatic vinyl compound which may be present in these polymer blocks B _{1 to} B ₅ may be distributed uniformly or in a taper shape. A plurality of the uniformly distributed portions and/or the tapered distribution portions may coexist in the polymer blocks B _{1 to} B ₅ .

The aromatic vinyl compound used to obtain the components (a) to (d) is styrene or t.
-Butylstyrene, α-methylstyrene, p-methylstyrene, divinylbenzene, 1,1-diphenylstyrene, N,N-dimethyl-p-aminoethylstyrene,
Examples thereof include N,N-diethyl-p-aminoethylstyrene and vinylpyridine, and styrene and α-methylstyrene are particularly preferable.

The conjugated dienes used to obtain the components (a) to (d) include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene,
1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,
3-octadiene, 3-butyl-1,3-octadiene, chloroprene and the like can be mentioned, but preferably 1,
3-Butadiene, isoprene and 1,3-pentadiene are preferred, and 1,3-butadiene is particularly preferred.

In the general formulas (I) to (II), the polymer blocks A ₁ , A ₂ , A ₅ and A _{6 have} a weight average molecular weight of 5,000.
0 to 20,000, preferably 7,000 to 18,000
It is 0. When the weight average molecular weight is less than 5,000, the dissolution time in asphalt is short and processing and handling are easy, but the softening point and toughness/tenacity are insufficient and insufficient, while when it exceeds 20,000, softening occurs. On the other hand, the toughness and tenacity are sufficiently large, but the dissolution time is remarkably lengthened and the melt viscosity of the asphalt composition is also increased, which makes processing and handling difficult.

(A) A block copolymer (A ₁ -B)
₁ ) nX, block A _{1 in} (A ₁ -B ₁ -A ₅ )nX
-B ₁ or A ₁ -B ₁ -A ₅ and the (b) block copolymers A ₂ -B ₂ and A ₂ -B ₂ -A _{6 have} a weight average molecular weight of 10,000 to 60,000. , Preferably 20,000 to 40,000. If the weight average molecular weight is less than 10,000, the softening point and toughness/tenacity of the obtained asphalt composition will be insufficient, and the fluidity resistance will also decrease significantly. On the other hand, if it exceeds 60,000, the toughness/tenacity becomes sufficiently large,
Compatibility with asphalt becomes poor and phase separation easily occurs.

In the general formulas (III) to (IV), A ₃ , A ₄ , A
₇ , A ₈ is a weight average molecular weight of 9,000 to 20,000,
Preferably, it is a polymer block mainly composed of 10,000 to 18,000 aromatic vinyl compounds. If the weight average molecular weight is less than 9,000, the softening point and toughness/tenacity are insufficient. On the other hand, if the weight average molecular weight is more than 20,000, it takes a long time to dissolve, the compatibility with asphalt becomes poor, and phase separation easily occurs. ..

(C) A block copolymer (A ₃ -B)
_{3) nY, (A 3 -B} 3 -A 7) A 3 -B 3 in nY,
The weight average molecular weight of A ₃ -B ₃ -A ₇ is 50,000
100,000, preferably 60,000 to 90,000
It is 0. When the weight average molecular weight is less than 50,000,
The softening point and toughness/tenacity of the obtained asphalt composition are insufficient, and the deterioration of fluidity becomes large. On the other hand, when it exceeds 100,000, the toughness/tenacity becomes sufficiently large, but the compatibility with asphalt becomes poor and phase separation easily occurs, and the melt viscosity of the asphalt composition becomes high, resulting in difficulty in processing and handling. Become.

Further, ( ₄ ) A ₄ which is a block copolymer
The weight average molecular weight of _{-B 4 -A 8, A 4 -B} 4 -A 8 -B 5 is 100,000-200,000, preferably 1
It is 20,000 to 180,000. When the weight average molecular weight is less than 100,000, the softening point and toughness/tenacity of the obtained asphalt composition are insufficient,
In addition, the fluidity resistance is also greatly reduced. On the other hand, 200,00
If it exceeds 0, the toughness/tenacity becomes sufficiently large, but the compatibility with asphalt becomes poor and phase separation easily occurs.

The total bond content of the polymer blocks A ₁ and A ₅ , A ₂ and A ₆ of the components (a) and (b) is 20 to 70% by weight, preferably 30 to 60% by weight. If this total bond content is less than 20% by weight, the softening point and toughness/tenacity will be insufficient, and the flow deformation resistance at high temperatures will also be insufficient. On the other hand, if it exceeds 70% by weight, the penetration of the asphalt composition is small and the asphalt composition becomes hard, and the low temperature flexibility decreases. The total bond content of the polymer blocks A ₃ and A ₇ , A ₄ and A ₈ of the component (c) and the component (d) is 20 to 45% by weight, preferably 30 to 35% by weight. This total bond content is 2
If it is less than 0% by weight, the softening point and the toughness/tenacity are insufficient, and the flow deformation resistance at high temperature is also insufficient. On the other hand, when it exceeds 45% by weight, toughness/tenacity and low temperature flexibility tend to be lowered.

Polymer block B of components (a) to (d)
The vinyl bond content in ₁ , B ₂ , B ₃ , B ₄ +B ₅ is 4
It is 0 to 70%, preferably 45 to 65%, more preferably 51 to 60%. When the vinyl bond content is in this range, the stability of physical properties before and after storage, the graspability of the aggregate, and the adhesiveness are improved in addition to the improvement of phase separation that occurs during high temperature storage. Further, since the melt viscosity is low, it has excellent processability. If the vinyl bond content is less than 40%, the phase separation property is improved, but the storage stability, dissolution time, and aggregate grasping effect are small. On the other hand, if it exceeds 70%, toughness/tenacity and low temperature flexibility are deteriorated.

The (b) block copolymer used in the present invention is obtained by first polymerizing an aromatic vinyl compound by using an organic alkali compound such as an organic lithium compound as a polymerization initiator in an inert hydrocarbon solvent. Then, after the conjugated diene is polymerized, a tin-based coupling agent, a tin-based terminal treating agent, or an ester-based coupling agent capable of forming the above-mentioned residue X is reacted, or an aromatic vinyl compound is polymerized again. After that, it can be produced by reacting a tin-based coupling agent, a tin-based terminal treatment agent, or an ester-based coupling agent. The (c) block copolymer is a tin-based coupling agent or a tin-based terminal treatment agent or an ester-based agent capable of forming the above-mentioned residue Y after similarly reacting an aromatic vinyl compound and a conjugated diene. It can be produced by reacting with a coupling agent other than the coupling agent. Furthermore, the (b) and (d) block copolymers can be produced by sequentially polymerizing an aromatic vinyl compound and a conjugated diene. The above general formulas (I) and (II
In I), n is an integer of 1 to 6, preferably 1 to 4, and when n exceeds 6, the weight average molecular weight of the triblock becomes extremely large and the viscosity of the asphalt composition becomes high, which is not preferable.

The above-mentioned inert hydrocarbon solvent is one of hydrocarbon solvents such as n-pentane, n-hexane, heptane, octane, methylcyclopentane, isopentane, cyclopentane, cyclohexane, benzene and xylene.
One kind or a combination of two or more kinds is possible, but cyclohexane is preferable. As the organic alkali metal compound that is a polymerization initiator, an organic lithium compound is preferable. As the organic lithium compound, an organic monolithium compound, an organic dilithium compound, or an organic polylithium compound is used. Specific examples of these include ethyl lithium, n-propyl lithium, isopropyl lithium, and n.
-Butyllithium, sec-butyllithium, isoprenyldilithium and the like are used, and used in an amount of 0.02 to 0.3 parts by weight per 100 parts by weight of the monomer.

Further, at this time, as a regulator (vinylating agent) of the microstructure, that is, the vinyl bond content of the conjugated diene portion, a Lewis base such as ether or amine, specifically diethyl ether, tetrahydrofuran, propyl ether, Butyl ether, higher ether, ethylene glycol butyl ether, ethylene glycol butyl ether, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, triethylene glycol butyl ether, ethylene glycol dibutyl ether, glycol ether derivatives such as propylene glycol diethyl ether, amines tetramethylethylenediamine, pyridine , Tertiary amines such as tributylamine, and the like, and monomer 1
Used in an amount of 0.02-0.2 parts by weight per 00 parts by weight with an inert hydrocarbon solvent.

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

The component (a) and the component (c) are used in the production of the block copolymer (a). The amount of the tin-based coupling agent (tin-based terminal treatment agent) or the ester-based coupling agent and the tin-based or ester is less than the equivalent amount. A coupling agent other than the system can be added to obtain a composition in which the components (a) and (c) are present at the same time. In addition, the components (a) and (d) remained after the addition of a tin-based coupling agent (tin-based end-treatment agent) or an ester-based coupling agent in an equivalent amount or less during the production of the (a) block copolymer. Chain extension of the block copolymer living anion
It can be obtained as a composition in which and (d) component are present at the same time.

The component (b) and the component (c) are, in the production of the block copolymer (b), less than an equivalent amount of a reaction terminator, a tin-based coupling agent (tin-based terminal treating agent) and an ester-based coupling agent. A coupling agent other than the above can be added to obtain a composition in which the components (b) and (c) are present at the same time. Further, the components (b) and (d) are added to the block copolymer (b) at the time of production of the block (b) by adding less than an equivalent amount of the reaction terminator, and then the remaining block copolymer living anion is chain-extended to obtain a component (b). It can be obtained as a composition in which the component (d) and (d) are present at the same time. In addition,
The components (i) to (d) may be prepared separately and mixed.

At this time, as the tin-based coupling agent,
Alkyltin halogen compounds such as dibutyldichlorotin, methyltrichlorotin, butyltrichlorotin, butyldibromotin, methyltribromotin and butyltribromotin, and tin halides such as tetrachlorotin and tetrabromotin are used. Examples of the system end treatment agent include triphenylchlorotin, trioctylchlorotin, and the like, but preferably dibutyldichlorotin, tetrachlorotin, trioctylchlorotin. Further, as the ester coupling agent,
Esters such as ethyl formate, ethyl acetate, butyl acetate, methyl propionate, phenyl acetate, ethyl benzoate and phenyl benzoate can be mentioned, with preference given to ethyl acetate and ethyl benzoate. The amount of these coupling agents used is about 0.05 to 0.6 molar ratio with respect to the organic alkali metal compound (preferably the organic lithium compound).

Examples of coupling agents other than tin-based and ester-based coupling agents include dihalogenated alkanes such as dibromomethane, dibromoethane, dibromopropane, methylene chloride, dichloroethane, dichloropropane, dichlorobutane, dichlorosilane, trichlorosilane, tetrachlorosilane. Halogenation of methyldichlorosilane, dimethyldichlorosilane, monoethyldichlorosilane, diethyldichlorosilane, monobutyldichlorosilane, dibutyldichlorosilane, monohexyldichlorosilane, dihexyldichlorosilane, dibromosilane, monomethyldichlorosilane, dimethyldibromosilane, etc. Silicon compounds, divinyl aromatic compounds such as divinyl benzene and divinyl naphthalene, bisphenol A, bisphenol AD, bisphenol F and other epoxy compounds, acid chlorides such as propionic acid chloride and adipic acid dichloride, 1,4-chloromethylbenzene and trivinylbenzene. Diisocyanate, γ-glycidoxypropyltri-α-methoxysilane and the like can be mentioned. The amount of the coupling agent used is about 0.05 to 0.5 with respect to the organic alkali metal compound (preferably organic lithium compound).
Used in molar ratio.

The bond content of the aromatic vinyl compound in the block copolymers (a) to (d) is adjusted by the amount of the monomer supplied during the polymerization in each stage, and is adjusted as necessary to the vinyl of the conjugated diene. The binding content is adjusted by varying the components of the microregulator. Also, (a)
(D) The weight average molecular weight of the block copolymer is adjusted by the addition amount of a polymerization initiator, for example, n-butyllithium.

Next, the (d) straight asphalt used in the present invention is obtained as a residue after subjecting the asphalt base crude oil to atmospheric distillation and steam or vacuum distillation. Since straight asphalt easily dissolves the block copolymers (a) to (d), processing,
Easy to handle. (E) Straight asphalt has a penetration of 40 to 150. If the penetration is less than 40, the flexibility at low temperature tends to be impaired, while 15
If it exceeds 0, the wear resistance and the flow resistance tend to decrease.

The asphalt composition of the present invention contains the above-mentioned components (a) to (e) as the main components, but the above-mentioned (a) component and (c) component or (d) component, (b) component and ( The weight ratio of component (c) or component (d) is 5 to 50/95 to 5
It is 0, preferably 10 to 30/90 to 70. (C)
If the weight ratio of the component or the component (d) is less than 50, the physical properties of the binder are insufficient, while if it exceeds 95, the compatibility with the asphalt becomes poor and phase separation tends to occur easily.

The weight ratio of the above-mentioned component (a) or component (b) to the total amount of component (c) or component (d) and component (e) is 2 to 20/98 to 80, preferably 3 to. 15/
97-85. When the weight ratio of the component (a) to the component (c) or the component (d), or the component (b) to the component (c) or the component (d) is less than 2, no asphalt modifying effect is observed and the softening point, Insufficient toughness/tenacity,
On the other hand, if it exceeds 20, the softening point and the toughness/tenacity are sufficient, but the dissolution time in asphalt becomes remarkably long, the compatibility becomes poor, and the melt viscosity of the composition becomes remarkably long, making processing and handling difficult. Become.

The block copolymers (a) to (d) of the present invention are usually used in the form of a pellet, a re-emulsified latex, a pellet made of a blend with another polymer, or a powder. You can In addition, the asphalt composition of the present invention is usually prepared by adding (a) to (a) straight asphalt under agitation melted at 140 to 190° C.
It is manufactured by adding the components (d) and mixing them.

The asphalt composition of the present invention contains
Small amounts of other styrene-butadiene-styrene block copolymers and styrene-isoprene-styrene-block copolymers can be used together. In addition, other thermoplastic elastomers or thermoplastic resins such as styrene-butadiene rubber latex, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, atactic polypropylene, 1,2-polybutadiene, or ethylene-propylene. It is possible to use other polymers such as rubber in combination. In this case, (a)-
The component (d) and the other polymer (thermoplastic elastomer and/or thermoplastic resin) may be kneaded at an arbitrary ratio and then pelletized for use. Further, the asphalt composition of the present invention, silica, talc, calcium carbonate and other fillers, pigments,
Additives such as an antiaging agent, a cross-linking agent, and a flame retardant can be added. Further, when used for road paving, gravel or the like can be added.

The preferred embodiment of the present invention is as follows. An asphalt composition in which the aromatic vinyl compound constituting the block copolymers (a) to (d) is styrene. An asphalt composition in which the conjugated diene constituting the block copolymers (a) to (d) is 1,3-butadiene. An asphalt composition in which a tin-based coupling agent is dibutyldichlorotin, dioctyldichlorotin, tetrachlorotin, a tin-based terminal treatment agent is trioctylchlorotin, and an ester-based coupling agent is ethyl acetate or ethyl benzoate. An asphalt composition in which the coupling agent other than tin-based and ester-based coupling agents is methyldichlorosilane, dibromoethane, tetrachlorosilane, and bisphenol A. An asphalt composition in which the vinylating agent is ethylene glycol diethyl ether, propylene glycol diethyl ether, tetrahydrofuran.

[0035]

The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, parts and% are based on weight unless otherwise specified. Moreover, various evaluations in the examples are obtained as follows.

Characteristic weight average molecular weight (Mw) of block copolymer GPC apparatus [Tosoh Corp. HLC-8020 type is used, and column is DuPont ZORBAX 1000.
It is the weight average molecular weight measured by standard polystyrene and measured by using 3 S]. Bound styrene content It was determined from the absorption intensity at 690 cm ⁻¹ using an infrared spectrophotometer (Perkin Elmer 1600 type). Vinyl bond content Using the infrared spectrophotometer (Perkin Elmer 1600 type), the Morello method [chem. e Ind. , 41, 75
8 (1959)], 967 cm ^-1 , 911c
It was determined from the absorption intensity at m ⁻¹ and 737 cm ⁻¹ .

Characteristic Dissolution Time of Asphalt Composition The dissolution time is determined by sampling a small amount of the content during mixing during coating of the asphalt composition, applying it on a polyester (Tetron) sheet, and observing it. It was the time until no solid particles were observed. Toughness Tenacity "Pavement Test Method Handbook" (November 1988, published by Japan Road Association) 3-5-17 Toughness Tenacity Test method was applied. Penetration, elongation, softening point, and frass embrittlement point Measured according to JIS K2207. Melt viscosity Measured at 140° C. with a B-type viscometer. Phase separation The prepared asphalt composition is poured into a cylindrical container made of a 300 cc aluminum can and placed in an oven for 180
After leaving it in a nitrogen atmosphere for 72 hours at ℃, cool it at room temperature, divide the aluminum can into upper and lower parts in the middle, and again melt and stir in the oven to adjust the upper and lower softening points, penetration, and melt viscosity. Compared. Storage stability Asphalt immediately after mixing (180°C, 1 hour), 18
The asphalt compositions after standing at 0° C. for 72 hours were compared for upper and lower softening points, penetration and melt viscosity.

Example 1 Preparation of Block Copolymer A 100 liter internal volume stainless steel polymerization vessel equipped with a jacket and a stirrer was sufficiently replaced with nitrogen gas, and 50 kg of cyclohexane and 3.6 kg of styrene were charged into the jacket. The contents were brought to 40° C. with warm water. Then, 15.0 g of sec-butyllithium was added to initiate polymerization. After the completion of the styrene polymerization, 15.0 g of ethylene glycol diethyl ether was added while passing cold water through the jacket so that the temperature of the contents became 80°C.
2.2 kg of 1,3-butadiene were added slowly.
After the polymerization of 1,3-butadiene was completed, 10.5 g of dibutyldichlorotin was added as a coupling agent,
Stir for 20 minutes. After the reaction was completed, 4.2 kg of 1,3-butadiene was slowly added. After the polymerization was completed, 7.8 g of methyldichlorosilane was added to 30
Stir for minutes. After the reaction, add 1 ml of methanol,
After stirring for 10 minutes, the content was taken out from the polymerization vessel, and 50 g of 2,6-di-t-butyl-4-methylphenol (BHT) which was an antioxidant was added. The polymerization solution was steam stripped, and the obtained water-containing polymer was crushed into a crumb by a crusher,
It was dried with hot air at ℃ to obtain a styrene-butadiene block copolymer containing the components (a) and (c).

Preparation of Asphalt Composition 570 g of straight asphalt having a penetration of 70 (manufactured by Kyodo Oil Co., Ltd., 60/80) and the above styrene-
30 g of the 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. Tables 1 and 3 show the evaluation results of each characteristic.

Example 2 Preparation of Block Copolymer A polymerization vessel made of stainless steel having an inner volume of 100 liter, equipped with a jacket and a stirrer, was sufficiently replaced with nitrogen gas, and then 50 kg of cyclohexane and 2.6 kg of styrene were charged into the jacket. The contents were brought to 40° C. with warm water. Then, 8.5 g of sec-butyllithium was added to initiate polymerization. After completing the polymerization of styrene, while passing cold water through the jacket so that the temperature of the contents becomes 80°C,
Propylene glycol diethyl ether 15.0 g,
2.2 kg of 1,3-butadiene were added slowly.
After the polymerization of 1,3-butadiene was completed, 2.1 ml of methanol was added as a reaction terminator and stirred for 20 minutes. After the reaction is complete, 1,3-butadiene 4.2
kg was added slowly. After the polymerization was completed, 1.0 kg of styrene was added and stirred for 30 minutes. After the reaction
After adding 4 ml of methanol and stirring for 10 minutes,
Remove the contents from the polymerization container,
6-di-t-butyl-4-methylphenol (BHT)
Was added. The polymerization solution is steam stripped, the obtained water-containing polymer is crushed into a crumb by a crusher, and then dried with hot air at 80° C. (b)
A styrene-butadiene block copolymer containing and (d) component was obtained.

Preparation of asphalt composition Using this styrene-butadiene block copolymer, an asphalt composition was prepared in the same manner as in Example 1. Tables 1 and 3 show the evaluation results of each characteristic.

Examples 3 to 8 and Comparative Examples 1 to 4 In Example 3 and Comparative Examples 1 and 2, 1,3-butadiene and se were used.
In the same manner as in Example 1 except that the charged amounts of c-butyllithium, ethylene glycol diethyl ether, dibutyldichlorotin, and methyldichlorosilane were changed,
Components (a) and (c) were obtained, and in Example 4, components (b) and (d) were obtained in the same manner as in Example 2 except that the vinylating agent was changed to tetrahydrofuran. Example 5
6, Comparative Examples 3 to 4 are (a) component, (b) component, (c)
The component and the component (d) were separately polymerized to obtain. Example 7
Is dibutyldichlorotin, (ha) component is dibromoethane, and in Example 8, (a) component is dibutyldichlorotin, (c) component is bisphenol A [produced by Yuka Shell Epoxy Co., Epicoat 825] was used, a block copolymer was obtained in the same manner as in Example 1, an asphalt composition was prepared in the same manner as in Example 1, and its performance was evaluated. The results are shown in Tables 1-6.

From Tables 1 to 6, the asphalt composition defined in the present invention has a fast dissolution time, improved storage stability, good tenacity characteristics, excellent graspability and adhesion of aggregates, Further, the melt viscosity is low and the workability is good. On the other hand, in Comparative Example 1, (a) component + (c)
It is an example in which the weight ratio of the component (a) in the components exceeds the upper limit,
Storage stability is improved, but softening point and toughness/tenacity are insufficient. Comparative Example 2 is (a) component + (c)
It is an example in which the weight ratio of the component (a) in the components is below the lower limit,
Although the effect of improving the physical properties is sufficient, the phase separation property tends to decrease. Comparative Example 3 is an example in which the vinyl bond content of the butadiene portion exceeds the upper limit, and although the dissolution time and storage stability are good, the asphalt composition becomes hard and the toughness/tenacity and low temperature flexibility tend to decrease. It is in.
Comparative Example 4 is an example in which the vinyl bond content of the butadiene portion is below the lower limit, and although the phase separation property is good, the physical properties deteriorate after high temperature storage and the effect of improving storage stability is insufficient.

Comparative Examples 5 to 12 Comparative Examples 5 to 12 are styrene, 1,3-butadiene and s.
By changing the charged amounts of ec-butyllithium and ethylene glycol diethyl ether, the (b) component and (d)
Components were separately prepared, a block copolymer was obtained in the same manner as in Example 1, an asphalt composition was prepared in the same manner as in Example 1, and its performance was evaluated. The results are shown in Tables 7-10.

As is clear from Tables 7 to 10, Comparative Example 5
Is an example in which the weight average molecular weight and bound styrene content of the polystyrene block of component (b) are below the lower limits, and the softening point and toughness/tenacity are reduced. Comparative Example 6
This is an example in which the weight average molecular weight of the polystyrene block and the triblock of the component (b) exceeds the upper limit, and the dissolution time becomes extremely long and the phase separation property deteriorates. Comparative Example 7
This is an example in which the weight average molecular weight of the polystyrene block and diblock of the component (b) is below the lower limit, and the softening point and toughness/tenacity are lowered. Comparative Example 8 is an example in which the bound styrene content of the component (b) exceeds the upper limit, and the toughness/tenacity and low temperature flexibility are reduced. Comparative Example 9
This is an example in which the weight average molecular weight of the polystyrene block and triblock of the component (d) exceeds the upper limit, the dissolution time is long, the phase separation property is significantly reduced, and the melt viscosity is also high.
Comparative Example 10 is an example in which the weight average molecular weights of the polystyrene block and the triblock of the component (d) are below the lower limits, the softening point and the toughness/tenacity are lowered, and the physical properties of the binder are insufficient. Comparative Example 11 is an example in which the bound styrene content of the component (d) exceeds the upper limit, and the toughness/tenacity and the brittleness at low temperature are reduced. Comparative Example 12
Is an example in which the bound styrene content of the component (d) is below the lower limit, and the softening point and toughness/tenacity decrease.

Examples 9 to 12 and Comparative Example 13 In Example 9, after completion of butadiene polymerization, styrene was polymerized again to obtain (a) and (c) block copolymers in the same manner as in Example 1. .. In Example 10 and Comparative Example 13, a coupling agent was used, (a) component was tetrachlorotin, and (c)
The component was changed to tetrachlorosilane, Example 11 used trioctylchlorotin as the terminal treatment agent for the component (a), methyldichlorosilane was used for the component (c), and Example 12 was used for the component (a). (I) In the same manner as in Example 1 except that the coupling agent was changed to ethyl benzoate.
And (c) a block copolymer was obtained, an asphalt composition was prepared in the same manner as in Example 1, and its performance was evaluated. The results are shown in Tables 11-12.

In Example 9, (a) component+(c) component is A
₅ is an example containing a component A ₇ , Example 10 is an example using a tetrafunctional coupling agent, Example 11 is an example using a tin-based terminal treating agent, and Example 12 is an example using an ester-based coupling agent. is there. From Tables 11 to 12, the asphalt composition defined in the present invention has a short dissolution time, improved storage stability, good tenacity characteristics, and excellent aggregate graspability and adhesiveness. Further, the melt viscosity is low and the workability is good. On the other hand, Comparative Example 13 is an example in which a tetrafunctional coupling agent is used and the weight average molecular weights of the components (a) and (c) exceed the upper limits, and the dissolution time becomes extremely long and the phase separation property deteriorates. To do. Also, the melt viscosity becomes high,
Workability is reduced.

Comparative Examples 14 to 17 In Comparative Examples 14 to 15, asphalt compositions were prepared in the same manner as in Example 1 except that the block copolymer of Example 1 was used and the addition amount to asphalt was changed. Then, the performance was evaluated. In Comparative Examples 16 to 17, the block copolymer of Example 1 was used, and the type of asphalt was changed to straight asphalt having a penetration of 180 (Showa Shell Co., Ltd., 150/200). 17 = penetration
15 blown asphalt [Showa Shell Co., Ltd., 1
0/20] except that the asphalt composition was prepared in the same manner as in Example 1 and its performance was evaluated. The results are shown in Tables 13-14. As is clear from Tables 13 to 14, when the addition amount of the block copolymer is less than the range specified in the present invention (Comparative Example 14), the physical properties of the binder are insufficient, while when too large (Comparative Example 15). Although the physical properties are sufficient, the dissolution time becomes long and the phase separation property is deteriorated.
In addition, the melt viscosity becomes extremely high, and the workability decreases.
Further, when the penetration of asphalt is larger than the range specified in the present invention (Comparative Example 16), the softening point tends to be lowered and the flow resistance is lowered, while when it is too small (Comparative Example 1).
7) The flexibility at low temperature is reduced, and phase separation easily occurs.

In Tables 1 to 14, used compounds A to
N is as follows. A; dibutyldichlorotin B; tetrachlorotin C; trioctylchlorotin D; ethyl benzoate E; methyldichlorosilane F; tetrachlorosilane G; dibromoethane H; Epicoat 825 (bisphenol A) I; ethylene glycol diethyl ether J; Propylene glycol diethyl ether K; Tetrahydrofuran L; Straight asphalt with penetration = 70 M; Straight asphalt with penetration = 180 N; Straight asphalt with penetration = 15

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

[0053]

[Table 4]

[0054]

[Table 5]

[0055]

[Table 6]

[0056]

[Table 7]

[0057]

[Table 8]

[0058]

[Table 9]

[0059]

[Table 10]

[0060]

[Table 11]

[0061]

[Table 12]

[0062]

[Table 13]

[0063]

[Table 14]

[0064]

The asphalt composition of the present invention has improved storage stability and good tenacity characteristics.
It has excellent graspability and adhesion of aggregate, low melt viscosity and good workability, and can be suitably used for road applications, waterproof sheets and the like.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inoue Nobuaki Inouguchi No. 34 Towada, Kamisu-cho, Kashima-gun, Ibaraki Prefecture JSR Shell Elastomer Co., Ltd.(72) Hiromitsu Imachi 34 Higashiwada, Kamisu-cho, Kashima-gun, Ibaraki Prefecture Address JSR Shell Elastomer Co. Inside the formula company

Claims (1)

[Claims] 1. (a) General formula (I); (A ₁ -B ₁ )n
A block copolymer represented by X and/or (A ₁ -B ₁ -A ₅ )nX (b) General formula (II); A ₂ -B ₂ and/or A _2-
B ₂ -A ₆ represented by the block copolymer (iii) the general formula _{(III); (A 3 -B} 3) nY and / or (A ₃ -B ₃ -A ₇₎ block copolymer represented by nY polymer (d) in formula _{(IV); A 4 -B 4} -A 8 and / or A ₄ -B ₄ -A ₈ block copolymer represented by -B ₅ [formula (I) ~ (II In the above, A ₁ , A ₂ , A ₅ , and A ₆ are polymer blocks mainly composed of an aromatic vinyl compound having a weight average molecular weight of 5,000 to 20,000, and B ₁ and B ₂ mainly composed of a conjugated diene. Polymer block, A ₁ -B ₁ , A
_{1 -B 1 -A 5, A 2} -B 2, A 2 -B 2 -A 6 is weight average molecular weight 10,000 to 60,000, X is a tin-based coupling agent and / or a tin terminated agent and /
Alternatively, the residue of the ester coupling agent, n represents an integer of _{1 to 6} , the total bond content of A ₁ and A ₅ , A ₂ and A ₆ is 20 to 70% by weight, and B ₁ and B ₂ The vinyl bond content of the conjugated diene moiety is 40-70%. In addition, in the general formulas (III) to (IV), A ₃ , A ₄ , A ₇ , and A ₈
Polymer block composed mainly of an aromatic vinyl compound having a weight average molecular weight 9,000～20,000 is, B _3, B _4,
B ₅ is a polymer block mainly composed of a conjugated diene, A ₃ −
_{B 3, A 3 -B 3 -A} 7 weight average molecular weight of 50,000
_{~100,000, A 4 -B 4 -A 8} , A 4 -B 4 -A
₈ -B ₅ weight average molecular weight 100,000～200,0
00 and Y are residues of coupling agents other than tin-based and/or ester-based, n is an integer of 1 to 6, and the total bond content of A ₃ and A ₇ , A ₄ and A ₈ is 20 to 45 weight. %, and the vinyl bond content of B ₃ , B ₄ +B ₅ is 40%.
Is about 70% by weight. (E) Weight of straight asphalt having a penetration of 40 to 150 as a main component, and the weight of the above (A) component and (C) component or (D) component, (B) component and (C) component or (D) component The ratio is 5 to 50/95 to 50, and the weight ratio of the component (a) or the component (b) to the component (c) or the component (d) to the component (e) is 2 to 20/98 to 80. There is an asphalt composition.