JPH0912898A - Asphalt composition - Google Patents

Abstract

PURPOSE: To prepare an asphalt compsn. having a high softening point and an excellent ductility and possessing excellent properties, such as mechanical strength, moldability, and storage stability by incorporating a block copolymer compsn. having a particular structure into asphalt. CONSTITUTION: 85 to 97wt.% asphalt is mixed with 3 to 15wt.% block copolymer (hereinafter abbreviated to 'BCP') compsn. comprising BCP of a polymer block (hereinafter abbreviated to 'PB') of a monovinyl arom. compd. (hereinafter abbreviated to 'MVAC') with a random copolymer block of MVC and a conjugated diene compd., the BCP satisfying the following requirements a) to d). a) At least one peak derived from BCP having one PB (hereinafter abbreviated to 'BCP-I') is present in a GPCmol.wt. range of from 50,000 to 150,000; b) at least one peak derived from BCP having two PBs (hereinafter abbreviated to 'BCP-II') is present in a GPCmol.wt. range of from 100,000 to 300,000; c) the total bonded MVAC content is 23 to 45wt.%; and d) the proportion of BCP-I occupies 20 to 70wt.% of BCP with the proportion of BCP-II occupying 30 to 80wt.% of BCP.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention uses a block copolymer composition having a specific structure as a modifier, and has a softening point and elongation,
And a novel asphalt composition having excellent physical properties such as mechanical strength, and further excellent processability and storage stability.

[0002]

2. Description of the Related Art Conventional asphalt compositions are used for road paving,
Widely used in applications such as waterproof sheets, sound insulation sheets, and roofing. At that time, many attempts have been made to add various polymers to asphalt to improve its properties.

As such polymers, ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, rubber latices, block copolymers comprising conjugated dienes and vinyl aromatic hydrocarbons, etc. are used.

However, an asphalt composition obtained by adding an ethylene-vinyl acetate copolymer or an ethylene-ethyl acrylate copolymer to asphalt is inferior in low-temperature properties and is not preferable because it may crack in winter. Also,
The elongation property is also poor, and therefore the caking force (tenacity) is also poor. Therefore, particularly in the case of road paving, the grasping property of the aggregate is poor.

Further, in the case of rubber latex, although the handling workability when mixing it with asphalt is good, it is economically or process-wise that extra heating is required to evaporate the water in the latex. There's a problem.

On the other hand, as a solution to the difficulty of latex rubber, there is an asphalt composition containing a block copolymer composed of an alkenyl aromatic compound and a conjugated diene compound. This composition has excellent low temperature properties and It has advantages such as excellent workability (Japanese Patent Publication No. 47-17319 and Japanese Patent Publication No. 59-36949).

However, although the temperature-sensitive property of asphalt is improved, there is a problem that the melt viscosity often varies when stored at high temperature because of its high melt viscosity and poor heat resistance.

Further, in order to improve mechanical strength, softening point, etc., JP-A-6-41439 and JP-A-3-281651.
Japanese patent publications and the like are disclosed. However, these materials have not yet reached a high softening point and excellent elongation.

[0009]

The present invention overcomes the drawbacks of the conventional asphalt composition, has a particularly high softening point and excellent elongation, and has physical properties such as mechanical strength and processing properties. The purpose of the present invention is to provide an asphalt composition having excellent properties (solubility in asphalt), an appropriate melt viscosity retention, and storage stability at high temperatures.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to develop an asphalt composition having the above-mentioned preferable physical properties, and as a result, have found that a monovinyl aromatic compound having a specific structure and a conjugated diene-based compound are used. It was found that the block copolymer with the compound achieves its purpose by an asphalt composition containing the compound in a specified range.
The present invention has been completed based on this finding.

That is, the present invention is a polymer block comprising a monovinyl aromatic compound (hereinafter referred to as "polymer block").
A) and a random copolymer block composed of a monovinyl aromatic compound and a conjugated diene compound (hereinafter abbreviated as “random copolymer block”), (a) gel permeation chromatography (Hereinafter, abbreviated as GPC), a block copolymer having one polymer block in a molecular weight in terms of standard polystyrene of 5,000,000 to 15,000,000 (hereinafter, referred to as "block copolymer (I Abbreviated as “)”), and (b) a block having two or more polymer blocks in a range of the standard polystyrene-converted molecular weight of 10,000,000 to 30,000,000 measured by GPC. It has at least one peak of a copolymer (hereinafter, abbreviated as "block copolymer (II)"), and (c) the total content of monovinylaromatic compounds is 23% by weight. Is 45% by weight, (d) the polymer block content (M) is 18% by weight to 35% by weight, and (e) the polymer block has a standard polystyrene-equivalent peak molecular weight measured by GPC of 1. Over 0,000 3.
The content (N) of the monovinylaromatic compound contained in the random copolymer block (f) is 6% to 25% by weight of the random copolymer block (g). The ratio (N / M) of N and M is more than 0.2 and less than 1, and (h) the monovinyl aromatic compound chain distribution in the random copolymer block has one monovinyl aromatic compound. Single chain (hereinafter S ₁
Abbreviated) is at least 50% by weight of bound monovinyl aromatic compound in the random copolymer block, monovinylaromatic compound abbreviated as 8 or more continuous monovinyl aromatic compound length chain (hereinafter _{S. 8 to)} random 15% by weight or less of the bound monovinylaromatic compound in the copolymer block, (i) the vinyl bond amount of the diene portion is 50% by weight or less, and the proportion of the (j) block copolymer (I) is It accounts for 20 to 70% by weight of the block copolymer, and the proportion of the block copolymer (II) (k) is 30% of that of the block copolymer.
Block copolymer composition 3 to 15 occupying 80% by weight
An asphalt composition comprising 85% by weight and 85-97% by weight of asphalt is provided.

Hereinafter, the present invention will be described in detail.

GPC of the block copolymer composition of the present invention
The molecular weight in terms of standard polystyrene has a peak molecular weight of at least one peak of the block copolymer (I) in the range of 5,000,000 to 15,000,000, and 10,000,000 to 30,000,000. It is necessary to have at least one peak of the block copolymer (II) within the range.

When the peak molecular weight of the block copolymer (I) is less than 50,000 or the peak molecular weight of the block copolymer (II) is less than 10,000,000, the mechanical strength and softening point of the asphalt composition are When the peak molecular weight of the block copolymer (I) exceeds 150000 or the peak molecular weight of the block copolymer (II) exceeds 30,000,000, the melt viscosity of the asphalt composition is remarkably high. In addition, the temperature will be high, and sufficient low-temperature elongation will not be exhibited, and the time until melting will be too long and the workability will be impaired.

The block copolymers (I) and (II) have peak molecular weights of 60,000 to 120,000 and 1 respectively.
It is preferably in the range of 20,000 to 2,500,000.

The block copolymer (II) has two or more polymer blocks, but one having two polymer blocks is preferable.

The block copolymer composition of the present invention has a total bound monovinyl aromatic compound content of 23% by weight to 45% by weight.

If it is less than 23% by weight, mechanical strength such as toughness and tenacity, a softening point and a sufficient elongation cannot be exhibited even when used as an asphalt modifier.
On the other hand, when it exceeds 45% by weight, low temperature flexibility such as low temperature elongation is remarkably reduced.

The preferred total bound monovinyl aromatic compound content is 25-40% by weight.

The content (M) of the polymer block in the block copolymer composition of the present invention is 18% by weight to 35% by weight, and the peak molecular weight of the polymer block is 10,000. It is necessary to exceed 30 thousand or less.

Polymer block content (M) is 18% by weight
Or less than 10,000 peak molecular weight of the copolymer block, sufficient cohesive force is not obtained, therefore the elongation of the asphalt compound, softening point, mechanical strength such as toughness tenacity is poor, on the other hand, When the polymer block content (M) exceeds 35% by weight or the peak molecular weight of the polymer block exceeds 30,000, the elongation is lowered and the solubility in asphalt is also poor.

The preferable polymer block content (M) and the peak molecular weight of the polymer block are 20 to 33, respectively.
It is more than 10% by weight and less than 25,000 and less than 25,000.

In order to obtain an asphalt composition excellent in elongation and having a high softening point and a high balance of toughness and tenacity, which is the object of the present invention, a monovinyl aromatic compound and a conjugated diene compound are used. The content (N) of the monovinyl aromatic compound contained in the random copolymer block is 6 wt% to 25 wt% of the random copolymer block. Within the extremely limited range, the ratio (N / M) of the content (N) of the monovinyl aromatic compound contained in the random copolymer block to the content (M) of the polymer block is , 0.2 and less than 1.

If the content (N) of the monovinyl aromatic compound in the random copolymer block is less than 6% by weight of the random copolymer block or if N / M is 0.2 or less, the temperature is normal temperature. When the elongation and the softening point are poorly balanced, the content (N) of the monovinyl aromatic compound in the random copolymer block exceeds 25% by weight of the random copolymer block, or N / M is 1 or more. In this case, the low temperature elongation and the softening point are poorly balanced.

The content (N) of the monovinyl aromatic compound contained in the random copolymer block is preferably 6 to 22% by weight, and the content of the monovinyl aromatic compound contained in the random copolymer block is contained. The ratio (N / M) between the amount (N) and the content (M) of the polymer block was 0.
It is preferably in the range of more than 25 and less than 0.95.

Further, the block copolymer composition of the present invention has a random copolymer block in the molecular chain. The chain distribution of the monovinyl aromatic compound in the random copolymer block is analyzed by GPC developed by Tanaka et al., Which is a degradation product obtained by ozone cleavage of all double bonds of conjugated diene units (high Proceedings of the Molecular Society, Vol. 29, No. 9, p. 2055).

The block copolymer of the present invention was analyzed by this method, and as a result, the ratio of S _{1 to} the total monovinyl aromatic compound chain in the range of 3000 or less in terms of polystyrene was found to be in the random copolymer block. It is necessary that 50% by weight or more of the bound monovinylaromatic compound and the proportion of S ₈ to be 15% by weight or less of the bound monovinylaromatic compound in the random copolymer block.

If S ₁ is less than 50% by weight or if S ₈ to more than 15% by weight, the random copolymer block is deteriorated in randomness, which is unfavorable because the low temperature elongation is decreased.

The preferable ratios of S ₁ and S ₈ are 60% by weight and 10% by weight, respectively.

The vinyl bond content in the random copolymer block of the present invention must be 50% by weight or less. When the vinyl bond content exceeds 50% by weight, the low temperature properties of the asphalt compound are remarkably inferior and the storage stability is also inferior, and the object of the present invention is not achieved.
Further, the melt viscosity of the block copolymer composition becomes high, and the processability such as the solubility when asphalt is blended becomes difficult, which is not preferable.

The preferred vinyl bond content is 40% by weight or less.

The proportion of the block copolymer (I) and the block copolymer (II) in the block copolymer composition constituting the present invention is 20 to 7 for the block copolymer (I).
0% by weight, and the block copolymer (II) is 80 to 3
0% by weight.

When the block copolymer (I) is more than 70% by weight or the block copolymer (II) is less than 30% by weight, the mechanical strength and softening point of the asphalt composition are not sufficiently improved. Yes, the storage stability becomes poor. Also,
When the block copolymer (I) is less than 20% by weight or the block copolymer (II) is more than 80% by weight, good elongation does not appear and it is disadvantageous in terms of processability such as solubility. Become.

Preferred block copolymers (I) and (I
The proportion of I) is 25 to 60% by weight of the block copolymer (I) and 75 to 40% by weight of the block copolymer (II).

Examples of the monovinyl aromatic compound of the block copolymer component constituting the present invention include styrene and
Examples of the monomer include p-methylstyrene, tert-butylstyrene, α-methylstyrene, and 1,1-diphenylethylene. Among them, styrene is preferable. These monomers may be used alone or in combination of two or more.

On the other hand, examples of the conjugated diene compound include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, piperylene, and 3-butyl-.
Examples include monomers such as 1,3-octadiene and phenyl-1,3-butadiene, among which 1,3-butadiene and
Isoprene is preferred. These monomers may be used alone or
Combinations of two or more species may be used.

The block copolymer composition of the present invention is prepared, for example, by first polymerizing a monovinyl aromatic compound using an organolithium compound or the like as a polymerization initiator in an inert hydrocarbon solvent, and then by conjugating a diene compound and a monovinyl aromatic compound. It can be produced by a method of reacting a specific coupling agent with a diblock copolymer obtained by copolymerizing and.

The polymerization temperature in these reactions is not particularly limited, but is usually 20 to 130 in consideration of productivity.
It is selected in the range of ° C. The polymerization initiation temperature is preferably 30 to
It is in the range of 90 ° C, and the highest temperature reaches 50 to 120.
This is the case in the range of ° C.

As the above-mentioned inert hydrocarbon solvent, for example, cyclohexane, n-hexane, benzene, toluene, octane and the like and mixtures thereof are used. Of these, cyclohexane is preferable, and the organolithium compound is also preferable. Are, for example, n-butyllithium, s
Examples thereof include ec-butyllithium and tert-butyllithium. Among these, n-butyllithium and sec-butyllithium are preferable.

The block copolymer composition of the present invention contains a random copolymer block, but it is possible to intentionally use a so-called randomizing agent when obtaining such a random copolymer. As such a randomizing agent, a small amount of an alkali metal tertiary alkoxide may coexist in an inert hydrocarbon solvent.

Examples of the alkali metal tertiary alkoxide include potassium-tert-amyl alcoholate, potassium-tert-butoxide and sodium-t.
Examples include ert-butoxide, cesium-tert-butoxide, potassium isopentyl oxide and the like, among which potassium-tert-amyl alcoholate is preferable.

In order to adjust the microstructure of the random copolymer block, a so-called vinylating agent can be added to the inert hydrocarbon solvent. As such an example,
Polar compounds such as ethers and tertiary amines such as ethylene glycol dimethyl ether, tetrahydrofuran, α-methoxytetrahydrofuran, N, N, N ′,
N′-tetramethylethylenediamine and the like, preferably tetrahydrofuran and N, N, N ′, N′-tetramethylethylenediamine, can be made to coexist in a predetermined amount, and these vinylating agents are not only used for adjusting the microstructure, Since it also has an effect as a randomizing agent, it is preferably used.

Further, in order to obtain a random copolymer block, in addition to the method using the above polar compound, Japanese Patent Publication No.
A randomization method by additionally adding a conjugated diene compound by the method described in JP-A-44089 may also be used.

In the block copolymer composition constituting the present invention, the block copolymer (I) may be polymerized first from either the polymer block or the random copolymer block. Further, the block copolymer (II) may be a polymer obtained by alternately polymerizing a polymer block and a random copolymer block, or may be one obtained by coupling the living end of the block copolymer (I).

The composition ratio of the block copolymer (I) and the block copolymer (II) can be adjusted by adjusting the block copolymer (I).
It may be adjusted by the amount of a coupling agent for coupling the living end after the polymerization of the block copolymer, or the block copolymer (I) and the block copolymer (II) which are separately polymerized.
May be mixed. Alternatively, the block copolymer (I) or the block copolymer (II) mixed with each other is mixed with the block copolymer (II) or the block copolymer (I).
May be mixed.

The block copolymer composition constituting the present invention may include a block copolymer (I) or a block copolymer (II) having a living terminal coupled thereto.

The coupling agent used in the present invention is a bifunctional or higher functional one. Examples of such polyfunctional coupling agents include diepoxy compounds and polyepoxides disclosed in JP-A-3-281515 and JP-A-3-287617, polyvinyl aromatic compounds and polyepoxides disclosed in JP-B-58-39444. There are isocyanates, polyimines, polyaldehydes, polyketones, polyhalides, polyanhydrides, carboxylic acid esters and the like.

Examples of diepoxy compounds include bisphenol A diglycidyl ether and bisphenol F diglycidyl ether.

Examples of the polyepoxide include epoxidized soybean oil, epoxidized linseed oil, and epoxidized polybutadiene.

As the polyvinyl aromatic compound, for example, m-divinylbenzene, p-divinylbenzene,
1,2,4-trivinylbenzene, 1,3-divinylnaphthalene, 1,8-divinylnaphthalene, 1.3.5
Trivinylnaphthalene, 2,4-divinylbiphenyl,
3,5,4'-trivinylbiphenyl, diisopropenylbenzene, 3,4,5,6-tetramethyl-1,2-
Examples include diisopropenylbenzene and the like.

Examples of polyisocyanates include benzene-1,2,4-triisocyanate and naphthalene-
1,2,5,7-tetraisocyanate, polyaryl polyisocyanate and the like.

Examples of polyimines include tri (1-aziridinyl) phosphine oxide and tri (2-methyl-1).
-Aziridinyl) phosphine oxide and the like, the polyaldehyde is, for example, 1,4,7-naphthalenetricarboxaldehyde, 1,7,9-anthracentricarboxaldehyde and the like, and the polyketone is, for example, 1,4 , 9,10-anthracene tetron and the like, examples of polyanhydrides include pyromellitic acid, styrene-maleic anhydride copolymers and the like, and examples of carboxylic acid esters include ethyl acetate and dimethyl adipate. , Diethyl adipate, triethyl citrate, 1,
3,5-tricarboethoxybenzene and the like.

The polyhalides include metal halogen compounds, organic metal halogen compounds and organic halogen compounds. Examples thereof include silicon tetrachloride, silicon tetrabromide, stannic chloride, trifluorosilane, trichlorosilane and trichloro. Ethylsilane, tribromobenzylsilane, dichlorodimethylsilane, dichlorodiethylsilane, methyltrichlorotin, diphenyldibromotin, carbon tetrachloride, dichloromethane, trichloroethylene, dichloroethylene, dibromoethane, dichlorobenzene, dibromobutane, hexachloroethane, hexachlorodisilane, etc. In addition to these, polyalkoxides of metals are also good examples, such as dimethoxysilane, diethoxysilane, trimethoxysilane, tetramethoxysilane, and tetraethoxysilane. It is a run, and the like.

Of these, bifunctional coupling agents are preferable, and diepoxy compounds are more preferable.

The bifunctional coupling agent referred to here is
It means a compound that substantially couples the ends of two living polymers.

These coupling agents may be used alone or in a mixture of two or more kinds.

The coupling reaction time is about 0.5 minutes to 2 hours, and the reaction temperature is 0 to 120 ° C.

The diepoxy compound more preferably used in the present invention has the general formula:

[0059]

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[Wherein R is

[0061]

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[0062]

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[0063]

[Chemical 6]

[0064]

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Wherein R ₁ and R ₂ are hydrogen or have 1 carbon atom
To an alkyl group of 20 to 20 or a phenyl group, R ₃ is an alkylene group of 2 to 20 carbon atoms, n is an integer of 0 to 10, and R ₄ and R ₅ are hydrogen or C _{1 to} C ₂₀ . It is an alkyl group, an alkoxy group, a phenyl group or a substituted phenyl group, R ₆ and R ₇ are C _{1 to} C ₂₀ alkyl groups or alkoxy groups, and R ₈ is a linear or branched C _{1 to} C _{30 group.} Is a hydrocarbon group (containing an oxygen atom), and l and m are integers of 0-4. ] The epoxy compound which is, or (e) group The alkylene oxide containing epoxy compound.

(F) Group Alicyclic epoxy compound.

Group (g) An epoxy compound containing a carbocyclic compound. The epoxy compound represented by the formula (1) or a mixture thereof (mixture of same group or mixture of different groups).

As a concrete example of the group (a),

[0069]

Embedded image (Bisphenol F type)

[0070]

Embedded image (Bisphenol A type)

[0071]

Embedded image (Bisphenol AD type)

[0072]

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[0073]

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[0074]

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[0075]

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[0076]

Embedded image However, the present invention is not limited to these.

Specific examples of the group (b) include the above (a).
Flock

[0078]

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[0079]

Embedded image And the like.

As a concrete example of the group (c),

[0081]

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[0082]

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[0083]

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[0084]

Embedded image However, the present invention is not limited to these.

As a concrete example of the group (d),

[0086]

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[0087]

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[0088]

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[0089]

Embedded image However, the present invention is not limited to these.

As a concrete example of the group (e),

[0091]

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[0092]

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[0093]

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[0094]

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[0095]

Embedded image However, the present invention is not limited to these.

As a concrete example of the group (f),

[0097]

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[0098]

Embedded image

[0099]

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[0100]

Embedded image

[0101]

Embedded image However, the present invention is not limited to these.

As a concrete example of the group (g),

[0103]

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[0104]

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[0105]

Embedded image

[0106]

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[0107]

Embedded image

[0108]

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[0109]

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[0110]

Embedded image

[0111]

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[0112]

Embedded image

[0113]

Embedded image However, the present invention is not limited to these.

Further, among the above groups, the (f) group, (g) group
Many of the groups have problems with safety and hygiene such as skin irritation, and should be handled with care. Therefore, group (a),
Group (b), group (c), group (d), and group (e) are preferable.

N of the diepoxy compound used in the present invention
The number is an integer in the range of 0-10, preferably 0-
5, more preferably an integer of 0 to 3. In addition, the content of the compound in which the n number is 0 (hereinafter referred to as n ₀ body) is preferably 95% by weight or more, and more preferably 98% by weight or more. If the number of n exceeds 10, the improvement of the softening point of the asphalt composition tends to be insufficient. Similarly, if the content of n ₀ isomer is less than 95% by weight, the improvement of the softening point of the asphalt composition will be insufficient.

On the other hand, the crystallinity increases as the n ₀ content approaches 100% by weight (especially in the group (a)), and it tends to be difficult to handle.

Therefore, when the diepoxy compound used in the present invention is of the group (a), bisphenol F and bisphenol AD types are preferable from the viewpoint of handleability, and further,
From the viewpoint of suppressing crystallization and reducing viscosity, use as a mixture of the same group or a mixture of different groups is most preferable.

As a concrete example,

[0119]

Embedded image When

[0120]

Embedded image Mixture with,

[0121]

Embedded image When

[0122]

Embedded image Mixture with,

[0123]

Embedded image When

[0124]

Embedded image Mixture with,

[0125]

Embedded image When

[0126]

Embedded image When

[0127]

Embedded image Mixture with,

[0128]

Embedded image When

[0129]

Embedded image When

[0130]

Embedded image However, the mixture is not limited to these.

The composition ratio of the mixture is such that each component amount is 1
To 99% by weight, preferably 20 to 80% by weight, more preferably 40 to 60% by weight (total amount of each component is 100% by weight).

In the diepoxy compound used in the present invention, the total chlorine content (by-product or residual) derived from epichlorohydrin, which is one of the starting materials, is preferably 1% by weight or less, particularly 0%. It is preferably 0.5% by weight or less. When the total chlorine content exceeds 1% by weight, the heat resistance of the asphalt composition is lowered and the melt viscosity tends to vary.

The block copolymer composition thus obtained may optionally contain a softening agent, an antioxidant, a light stabilizer,
An antiblocking agent or the like can be added.

Examples of the softening agent include naphthene-based, paraffin-based, aroma-based process oils and mixed oils thereof. Among them, naphthene-based, paraffin-based oils and mixed oils thereof are preferable. .

Examples of the antioxidant include 2,6-
Di-tert-4-methylphenol, n-octadecyl-3- (4′-hydroxy-3 ′, 5′-di-ter
t-Butylphenyl) propionate, 2,2'-methylenebis (4-methyl-6-tert-butylphenol), 2,4-bis [(octylthio) methyl] -o-
Cresol, 2-tert-butyl-6- (3-ter
t-butyl-2-hydroxy-5-methylbenzyl)-
4-methylphenyl acrylate, 2,4-di-ter
Hindered phenolic antioxidants such as t-amyl-6- [1- (3,5-di-tert-amyl-2-hydroxyphenyl) ethyl] phenyl acrylate; dilauryl thiopropionate, lauryl stearyl thiodipro Sulfur-based antioxidants such as pionate and pentaerythritol-tetrakis (β-laurylthiopropionate); tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl)
Examples thereof include phosphorus-based antioxidants such as phosphite.

As the light stabilizer, for example, 2-
(2'-Hydroxy-2'-methylphenyl) benzotriazole, 2,2'-hydroxy-3 ', 5'-te
rt-butylphenyl) benzotriazole, 2-
Benzotriazole-based UV absorbers such as (2'-hydroxy-3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole and 2-hydroxy-4.
Examples thereof include benzophenone-based UV absorbers such as methoxybenzophenone and hindered amine-based light stabilizers.

Further, examples of the antiblocking agent include higher fatty acids, metal salts of higher fatty acids, waxes, fatty acid amides, fatty acid esters, inorganic metal salts and hydroxides.

Next, the asphalt component constituting the present invention is not particularly limited, and includes commonly used asphalt, for example, straight asphalt, (semi) blown asphalt, and a mixture thereof.
Preferable examples include straight asphalt having a penetration of 40 to 120, blown asphalt having a penetration of 10 to 30 and a mixture thereof.

The composition ratio of the block copolymer composition in the asphalt composition of the present invention varies depending on the type of asphalt and its application, but in consideration of physical properties, processability, and workability, the asphalt component 85 to 85 is used. 9
3 to 15% by weight is added per 7% by weight. If the blending amount is less than 3% by weight, the modifying effect of the asphalt will not be exhibited, and if the blending amount exceeds 15% by weight, no further modifying effect will be obtained, and the melt viscosity of the asphalt will remarkably increase. Then, it is economically and performancely disadvantageous in that the workability is impaired.

The asphalt composition thus prepared may be filled, if necessary, with various additives conventionally used in asphalt compositions, such as silica, talc, calcium carbonate, mineral powder and glass fiber. Agents and reinforcing agents, mineral aggregates, softeners such as pigments and process oils, foaming agents such as azodicarbonamide, polyethylene, atactic polypropylene, polyolefin-based such as ethylene-ethyl acrylate copolymer or low molecular weight Vinyl aromatic thermoplastic resin; natural rubber; polyisoprene, polybutadiene, styrene-butadiene rubber, chloroprene rubber, acrylic rubber, isoprene-isobutylene rubber, polypentenamer rubber, and styrene-butadiene block copolymers other than the present invention. , Styrene-isoprene block Synthetic rubbers such as copolymers may be added.

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

The method of mixing the block copolymer composition of the present invention and the asphalt is not particularly limited, and if desired, the above-mentioned various additives may be added, for example, a homomixer, a heat melting pot, a roll, a kneader, a Banbury mixer. It can be prepared by heating, melting and kneading with an extruder or the like.

[0143]

Hereinafter, the present invention will be described with reference to Examples.
These examples do not limit the invention.

The charged amounts and the like of each Example and Comparative Example are shown in Tables 1 and 2, and the physical properties of the obtained block copolymer composition and asphalt composition are shown in Tables 3 to 6. In addition, various measurements followed the following method.

1. Measurement of physical properties of block copolymer composition 1) Total styrene content : UV spectrophotometer (manufactured by JASCO Corporation;
V-520) and calculated from the absorption intensity at 262 nm.

2) Peak molecule of block copolymer composition
Amount and composition ratio : GPC [The device is manufactured by Waters, and the column is ZORBAX PSM 1000
It is a combination of two S and three PSM 60-S. Tetrahydrofuran is used as the solvent, and the measurement conditions are
The peak molecular weight and the composition ratio were determined from the chromatogram at a temperature of 35 ° C., a flow rate of 0.7 ml / min, a sample concentration of 0.1% by weight, and an injection amount of 50 μl.

The peak molecular weight is a value converted from the following standard polystyrene (manufactured by Waters) calibration curve.

1.75 × 10 ⁶ , 4.1 × 10 ⁵ , 1.1
2 x 10 ⁵ , 3.5 x 10 ⁴ , 8.5 x 10 ³

3) Block styrene content (M) : oxidative decomposition method using osmium tetroxide and tert-butyl hydroperoxide [described in "Journal of Polymer Science" Vol. 1, p. 429 (1946)]
Was determined in accordance with

The weight of the styrene polymer block was measured using an ultraviolet spectrophotometer (manufactured by JASCO Corporation) at 262n.
It was calculated from the absorption intensity of m.

4) Block styrene peak molecular weight : The block styrene prepared according to the method of 3) above is G
PC [The device is made by Waters, the column is a combination of K-801, 802, 803 made by Shodex in total, chloroform is used as a solvent, the measurement conditions are a temperature of 35 degrees and a flow rate of 1.0 ml / Min, sample concentration 0.1% by weight, injection volume 50 μl], the peak molecular weight was determined.

The molecular weight is a value converted from the following standard polystyrene (manufactured by Waters) calibration curve.

35,000, 8,500, 2,350,
780, 680, 580, 470

The number of polymer blocks composed of the monovinyl aromatic compound of the block copolymer can be determined from the charged amount and the conversion, or the butadiene-corrected molecular weight and block of the block copolymers (I) and (II) can be obtained. It can be determined from the content and molecular weight of the styrene portion.

Further, the content (N) of the monovinyl aromatic compound in the random copolymer block can be similarly obtained from the charged amount and the conversion, and also from the analysis results by the above methods 1) and 3). be able to.

5) Styrene of random copolymer block
Linkage distribution : analyzed by the method developed by Tanaka et al.
Specifically, the styrene chain distribution is analyzed by GPC of a decomposition product obtained by ozone cleavage of all double bonds of the butadiene unit (Proceedings of the Polymer Society of Japan, Vol. 29, No. 205.
5).

[0157] The chromatogram obtained by the method of Tanaka et al., To the area of the following chromatogram molecular weight 3000, the value of S ₁ from the ratio of the area of the chromatogram which corresponds to one of a styrene single chain (S _1), also The value of _{S8- was calculated} from the ratio of the area of the chromatogram corresponding _{to the} styrene long chain ( _S8- ) in which eight or more styrenes were connected.

6) Microstructure of butadiene part : Measured using an infrared spectrophotometer (manufactured by Perkin Elmer) and determined by the Hampton method.

[0159] 2. Measurement of physical properties of asphalt composition 1) Melt viscosity : Measured with a Brookfield viscometer at 180 ° C.

2) Toughness and tenacity : Measured according to the test method for paving work (edited by Japan Road Construction Industry Association).

3) Elongation and softening point : Measured according to JIS-K2207.

4) Solubility in asphalt : The solubility of the block copolymer in asphalt was visually determined and evaluated in 5 ranks.

⊚: When completely dissolved within 20 minutes ◯: When the content exceeds 20 minutes and is completely dissolved within 35 minutes. Δ: When the content exceeds 35 minutes and is completely dissolved within 50 minutes. X: When the solution is over 50 minutes and completely dissolved within 70 minutes. XX: When dissolution took 70 minutes or more.

5) Storage stability : Asphalt composition,
Stir at 160 ° C for 2 days, and change the initial melt viscosity by 5
It was evaluated by rank.

⊚: When the rate of change is within 20%. ◯: When the rate of change exceeds 20% and is within 35%. Δ: When the rate of change exceeds 35% and is within 50%. X: When the rate of change exceeds 50% and is within 65%. XX: When the rate of change exceeds 65%.

Example 1 A 10 L stainless steel reactor equipped with a jacket and a stirrer was sufficiently replaced with nitrogen, and then cyclohexane 5720 g, N, N, N ′, N′-tetramethylethylenediamine (TMEDA) 0.6 g , Tetrahydrofuran 1.9 g and styrene (referred to as first styrene) 240 g were charged, and warm water was passed through the jacket to set the content at 60 ° C.

After that, an n-butyllithium cyclohexane solution (1.5 g in pure content) was added to initiate polymerization of the first styrene. 1 after the first styrene is almost completely polymerized
After 0 minutes, 640 g of 1,3-butadiene and styrene (second
A mixture with 120 g of styrene) was added and the polymerization was continued. 5 minutes after the contents were completely polymerized and reached the maximum temperature of 77 ° C, a 1: 1 mixture of bisphenol A diglycidyl ether and bisphenol F diglycidyl ether represented by the following formula as a coupling agent (hereinafter referred to as coupling agent). X is provided; however, n is an integer of 0 or more, and the content of the compound in which the number of n is 0 is 98% by weight or more.) 0.5 equivalent to n-butyllithium was added and coupled. It was

[0168]

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[0169]

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Thirty minutes after the addition of the coupling agent, 0.5 g of water was added. Immediately after the first primary styrene was charged, the system was continuously stirred by a stirrer during this period.

Thereafter, the block copolymer composition solution was extracted, and an antioxidant (0.7 g of 2,6-di-tert-butyl-methylphenol per 100 parts by weight of the block copolymer composition, tris (nonylphenyl) was used. ) Phosphite 0.8 g and tris (2,4-di-tert-butylphenyl) phosphite 0.4 g / cyclohexane solution) were added and the solvent was removed by steam stripping the resulting solution, Subsequently, it was dehydrated and dried on a hot roll (120 ° C.) to obtain a block copolymer composition.

25 g of the obtained block copolymer composition and straight asphalt (Far East Stores 60/80) 4
75 g was melt-kneaded at 180 ° C. for 90 minutes to prepare an asphalt composition.

(Example 2) A 10 L stainless steel reactor equipped with a jacket and a stirrer was sufficiently replaced with nitrogen, and then 5720 g of cyclohexane, 18 g of tetrahydrofuran,
240 g of styrene was charged and warm water was passed through the jacket to set the content to 58 ° C.

Thereafter, an n-butyllithium cyclohexane solution (1.7 g in pure content) was added to initiate polymerization of styrene. Ten minutes after the styrene was almost completely polymerized, a mixture of 690 g of 1,3-butadiene and 70 g of styrene was added, and the polymerization was continued. After the content completely polymerized and reached the maximum temperature of 76 ° C, 5 minutes later, the coupling agent X
Was added in an amount of 0.7 equivalent to n-butyllithium and coupled.

Thirty minutes after the addition of the coupling agent, 0.5 g of water was added. Immediately after charging the first styrene, the system was continuously stirred by a stirrer during this period.

Thereafter, the same operation as in Example 1 was carried out to obtain a block copolymer composition.

Using the obtained block copolymer composition,
An asphalt composition was prepared in the same manner as in Example 1.

(Examples 3, 5, 12 and Comparative Example 4) A block copolymer composition and asphalt were prepared in the same manner as in Example 2 except that the amount of catalyst, the amount of styrene, the amount of butadiene and the amount of coupling agent were changed. A composition was obtained.

(Example 4) A 10-liter stainless reactor equipped with a jacket and a stirrer was sufficiently replaced with nitrogen, and then 5720 g of cyclohexane and 2.0 of tetrahydrofuran.
g, 230 g of styrene (referred to as first styrene) were charged, and warm water was passed through the jacket to set the content at 70 ° C.

After that, an n-butyllithium cyclohexane solution (1.8 g in pure content) was added to initiate polymerization of styrene. Five minutes after the first styrene was almost completely polymerized, a mixture of 260 g of 1,3-butadiene and 160 g of styrene (referred to as second styrene) was added, the polymerization was continued, and after 2 minutes, 40 minutes by a metering pump. Then, 350 g of the remaining 1,3-butadiene was continuously fed into the polymerization system to continue the polymerization. Five minutes after almost completely polymerizing and reaching the maximum temperature of 75 ° C., 0.7 equivalent of the coupling agent X to lithium was added and coupling was performed.

Thirty minutes after the addition of the coupling agent, 0.8 g of water was added. Immediately after charging the first styrene,
During this period, the inside of the system was continuously stirred by a stirrer.

Thereafter, a block copolymer composition was obtained in the same manner as in Example 1.

Using the block copolymer composition thus obtained,
An asphalt composition was prepared in the same manner as in Example 1.

Example 6 In Example 6, a block copolymer composition was obtained by mixing the following two types of block copolymers (A and B) in cyclohexane.

Block copolymer A: except that the amount of the coupling agent X was changed and the amount of the component (I) was changed to 30%.
The same operation as in Example 1 was carried out to polymerize the block copolymer A, and after completion of the reaction, 0.5 g of water was added and sufficiently stirred, and then the cyclohexane solution was extracted from the reactor.

Block copolymer B: The same procedure as in Example 1 was repeated except that the amounts of the first and second styrenes were changed to 300 g and 60 g, respectively, and the coupling agent X was not added. B was polymerized, and after completion of the reaction, water was reduced to 0.
After adding 5 g and stirring sufficiently, the cyclohexane solution was extracted from the reactor.

Cyclohexane solutions of block copolymers A and B were mixed and adjusted so that the ratio of the component having two polystyrene blocks and the component having one polystyrene block was 50:50. Then, the same operation as in Example 1 was performed to obtain a block copolymer composition and an asphalt composition.

(Comparative Example 1) A block copolymer composition was prepared in the same manner as in Example 2 except that the amount of catalyst, the amount of first styrene, the amount of butadiene and the amount of coupling agent were changed, and that no second styrene was added. And an asphalt composition were obtained.

(Comparative Example 2) A block copolymer composition and an asphalt composition were obtained in the same manner as in Example 1 except that the catalyst amount and the coupling agent were changed to tetrachlorosilane.

(Comparative Examples 3 and 6) The block copolymer composition and the asphalt composition were prepared in the same manner as in Example 4, except that the catalyst amount, styrene amount, butadiene amount, and coupling agent amount were changed. Obtained.

(Comparative Example 9) A block copolymer composition and an asphalt composition were obtained in the same manner as in Example 1 except that the amount of catalyst and the amount of coupling agent were changed.

Comparative Example 10 A block copolymer composition and an asphalt composition were obtained in the same manner as in Example 1 except that the amount of coupling agent was changed.

(Comparative Example 11) A 10-liter stainless steel reactor equipped with a jacket and a stirrer was sufficiently replaced with nitrogen.
5720 g of cyclohexane, 120 g of styrene (referred to as first styrene), 0.6 g of TMEDA, and 1.9 g of tetrahydrofuran were charged, and warm water was passed through the jacket to set the content at 60 ° C.

After that, an n-butyllithium cyclohexane solution (1.1 g in pure content) was added to initiate polymerization of the first styrene. 1 after the first styrene is almost completely polymerized
After 0 minutes, 640 g of 1,3-butadiene and styrene (second
A mixture with 120 g of styrene) was added and the polymerization was continued. After the content completely polymerized and reached the maximum temperature of 72 ° C., 15 minutes later, 120 g of styrene (referred to as tertiary styrene) was added to continue the polymerization, and after the tertiary styrene was almost completely polymerized, After maintaining for an additional 15 minutes to complete the polymerization, water was added to completely deactivate the active species.
Immediately after the first styrene was charged, the system was continuously stirred by a stirrer during this period.

Thereafter, in the same manner as in Example 1, a block copolymer and an asphalt composition were obtained.

(Example 7) In Example 7, a block copolymer was obtained by mixing the following two types of block copolymers (C and D) in cyclohexane.

Block copolymer C: Polymerization of the block copolymer C was carried out in the same manner as in Comparative Example 11 except that the amount of the catalyst was changed. After completion of the reaction, water was added and the mixture was sufficiently stirred. The cyclohexane solution was extracted.

Block copolymer D: The block copolymer D was polymerized in the same manner as in Example 1 except that the coupling agent X was not added. After the reaction was completed, 0.5 g of water was added.
After adding and stirring well, the cyclohexane solution was extracted from the reactor.

Cyclohexane solutions of block copolymers C and D were mixed and adjusted so that the component ratio of C and D was 50:50. Then, the same operation as in Example 1 was performed to obtain a block copolymer composition and an asphalt composition.

(Example 8, Comparative Examples 5 and 7) The same operations as in Example 1 were carried out except that the amount of catalyst, the amount of styrene, the amount of butadiene and the amount of coupling agent were changed, and the block copolymer composition and An asphalt composition was obtained.

Example 9 A block copolymer was prepared in the same manner as in Example 2 except that the amount of catalyst, the amount of styrene, the amount of butadiene, and the coupling agent were changed to dimethyldimethoxysilane, and the amount of the coupling agent was changed. A composition and an asphalt composition were obtained.

(Example 10) A block copolymer composition and a block copolymer composition were prepared in the same manner as in Example 4 except that the amount of catalyst, the amount of styrene, the amount of butadiene, and the coupling agent were changed to ethyl acetate and the amount of coupling agent was changed. An asphalt composition was obtained.

Example 11, Comparative Example 8 A block copolymer was prepared in the same manner as in Example 1 except that the catalyst amount, the styrene amount, the butadiene amount, and the coupling agent were changed to dichlorodimethylsilane. A polymer composition and an asphalt composition were obtained.

(Comparative Example 12) A block copolymer composition and an asphalt composition were obtained in the same manner as in Example 2 except that the amount of catalyst and the amount of coupling agent were changed.

(Comparative Example 13) In Comparative Example 13, when the same operation as in Example 1 was carried out, TMEDA was added to cyclohexane.
Was added and coexisted with 1.5 g to obtain a block copolymer composition and an asphalt composition in the same manner as in Example 1 except that the vinyl content in butadiene was changed.

(Comparative Example 14) A 10-liter stainless steel reactor equipped with a jacket and a stirrer was sufficiently replaced with nitrogen,
Cyclohexane 5720 g, styrene 240 g, and tetrahydrofuran 1.5 g were charged, and warm water was passed through the jacket to set the content at 60 ° C.

After that, an n-butyllithium cyclohexane solution (1.5 g in pure content) was added to initiate polymerization of styrene. Ten minutes after the styrene was almost completely polymerized, a mixture of 640 g of 1,3-butadiene and 120 g of styrene was added, and the polymerization was continued. After the content completely polymerized and reached the maximum temperature of 76 ° C., 5 minutes later, 0.5 equivalent of the coupling agent X was added to n-butyllithium for coupling.

Thirty minutes after the addition of the coupling agent, 0.5 g of water was added. Immediately after the first styrene was charged, the system was continuously stirred by a stirrer during this period.

Thereafter, the block copolymer composition and the asphalt composition were obtained in the same manner as in Example 1.

[0210]

[Table 1]

[0211]

[Table 2]

[0212]

[Table 3]

[0213]

[Table 4]

[0214]

[Table 5]

[0215]

[Table 6]

From Tables 3 to 6, the total styrene content of the block copolymer, the block styrene content (M), the styrene content of the random copolymer block (N), and the styrene content of the random copolymer block (N) ) To block styrene content (M) (N / M), vinyl content, component amounts before and after coupling, molecular weight of block copolymer and block styrene, styrene chain distribution of random copolymer block, block copolymer weight When the composition ratio of the polymer (I) and the block copolymer (II) is within the limited range, the solubility in asphalt, the excellent balance between the elongation and the softening point,
It can be seen that performance such as toughness and tenacity, and asphalt performance excellent in storage stability are exhibited.

[0219]

The novel asphalt composition of the present invention is
It consists of a block copolymer composition with a specific structure and asphalt, and it has an excellent balance of elongation and softening point, as well as mechanical properties such as toughness and tenacity, and excellent workability balance such as solubility in asphalt. Can provide modified asphalt.

Since the asphalt composition of the present invention has the above-mentioned characteristics, it is used, for example, as a waterproof sheet, a waterproof material, a silencer sheet, and a steel pipe coating, and is particularly suitable for road paving. Is.

Claims (6)

[Claims] 1. A polymer block composed of a monovinyl aromatic compound (hereinafter abbreviated as “polymer block”) and a random copolymer block composed of a monovinyl aromatic compound and a conjugated diene compound (hereinafter referred to as “random copolymer block”). In the block copolymer consisting of
(A) A block copolymer having one polymer block in a molecular weight in terms of standard polystyrene measured by gel permeation chromatography (hereinafter abbreviated as GPC) of 50000 to 150000 ( In the following, abbreviated as "block copolymer (I)") has at least one peak, and (b) the weight average molecular weight in terms of standard polystyrene measured by GPC is in the range of 10,000,000 to 30,000,000. A block copolymer having two or more united blocks (hereinafter abbreviated as "block copolymer (II)") has at least 1 peak.
And the total content of (c) monovinyl aromatic compounds is 2
3 wt% to 45 wt%, (d) polymer block content (M) is 18 wt% to 35 wt%, and (e) polymer block peak molecular weight measured by GPC in terms of standard polystyrene. Is more than 10,000 and not more than 30,000, and the content (N) of the monovinyl aromatic compound contained in the random copolymer block (f) is 6% by weight to the random copolymer block. 25% by weight, (g) N
And the ratio of M (N / M) exceeds 0.2 and is smaller than 1,
(H) In the chain distribution of the monovinyl aromatic compound in the random copolymer block, the monovinyl aromatic compound is 1
Single monovinyl aromatic compound single chain (hereinafter abbreviated as S ₁ )
But at least 50% by weight of bound monovinyl aromatic compound in the random copolymer block, monovinyl aromatic compound (hereinafter abbreviated as _{S. 8 to)} 8 or more continuous monovinyl aromatic compound length chain random copolymer 15% by weight or less of the bound monovinylaromatic compound in the block,
(I) The vinyl bond content of the diene portion is 50% by weight or less, the proportion of the (j) block copolymer (I) accounts for 20 to 70% by weight of the block copolymer, and (k) the block copolymer weight. The ratio of the compound (II) is 30 to 8 of the block copolymer.
An asphalt composition comprising 3 to 15% by weight of a block copolymer composition occupying 0% by weight and 85 to 97% by weight of asphalt. 2. The asphalt composition according to claim 1, wherein the block copolymer (II) has two polymer blocks. 3. The asphalt composition according to claim 1, wherein the block copolymer (II) is obtained by coupling living ends. 4. The asphalt composition according to claim 3, wherein the coupling agent used for coupling the living end is bifunctional. 5. The asphalt composition according to claim 4, wherein the coupling agent is partially or wholly a diepoxy compound. 6. A part or all of the diepoxy compound is represented by: And [Chemical 2] (However, n is an integer greater than or equal to 0, and the content of the compound in which n is 0 is 95 weight% or more.), The asphalt composition of Claim 5 characterized by the above-mentioned.