Asphalt emulsion decomposer composition and use thereof

Abstract

To provide a decomposing agent composition for an asphalt emulsion, which exhibits excellent decomposability for the asphalt emulsion, has high permeability such that separation between asphalt and water proceeds to a non-contact lower layer part in a short time, and is excellent in asphalt film-forming properties.SOLUTION: An asphalt emulsion-decomposing agent composition comprising (A) a sulfur-containing anionic surface active agent, (B) a sulfur-containing inorganic salt, (C) an organic compound having a water-solubility of 20g / 100g or less at a temperature of 20 °C, and water, wherein the pH of the decomposing agent composition at a temperature of 20 °C is 10 or more, and the specific weight of the decomposing agent composition at a temperature of 20 °C is 1.03 to 1.50.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a decomposer composition for asphalt emulsion and its use. [Background technology]

[0002] Asphalt is the final refined product obtained after petroleum distillation to extract naphtha, gasoline, kerosene, diesel, etc., and has long been used as a paving material. Asphalt is a highly viscous semi-solid or solid at room temperature, and its high adhesiveness makes it very difficult to handle. One known method for improving workability during handling at room temperature is to use asphalt in a form emulsified in water using an emulsifier, and this emulsion is called asphalt emulsion. One way to classify asphalt emulsions is by the emulsifier used, which can be cationic, anionic, nonionic, etc., and the majority of asphalt emulsions used for road paving are cationic asphalt emulsions.

[0003] Required properties of asphalt emulsion include storage stability from the time of its production until its use at the construction site, and mechanical stability to prevent the emulsion from breaking down even when subjected to external forces such as shear and compression from pumps used to transport and spray the emulsion. Furthermore, it is highly desirable for the asphalt emulsion to separate into water and asphalt in a short time after being sprayed at the construction site. This is because if moisture remains in the asphalt, it will not have the inherent adhesiveness that asphalt should have, resulting in poor adhesion. Generally, after spraying asphalt emulsion, it is necessary to wait until the moisture in the agent has evaporated and fully decomposed, during which time traffic restrictions are required on the road, resulting in a long time before the road can be reopened to traffic.

[0004] To solve this problem, a method using a decomposer that breaks down the emulsion of the asphalt emulsion is known, and specific decomposers for cationic asphalt emulsions are proposed in Patent Documents 1 to 4. However, the decomposition agents described in Patent Documents 1 to 4 are unable to sufficiently decompose asphalt emulsion, particularly when a large amount of asphalt emulsion is sprayed, and problems may arise such as undecomposed emulsion remaining in the lower layer or water that has separated from the asphalt mixed with the undecomposed asphalt emulsion remaining on the road surface. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-122352 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-164345 [Patent Document 3] Japanese Patent Application Publication No. 2023-161595 [Patent Document 4] Japanese Patent Application Laid-Open No. 2024-045049 Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide an asphalt emulsion decomposer composition that exhibits excellent decomposition properties for asphalt emulsions, has high permeability that allows separation of asphalt and water to progress to non-contact lower layer portions in a short period of time, and has excellent asphalt film-forming properties. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have discovered that the above-mentioned problems can be solved by a decomposing agent composition for asphalt emulsion that contains specific components and exhibits specific physical properties, and have arrived at the present invention. That is, the decomposer composition for the asphalt emulsion of the present invention contains a sulfur-containing anionic surfactant (A), a sulfur-containing inorganic salt (B), an organic compound (C) having a solubility in water of 20 g / 100 g or less at a temperature of 20°C, and water, and the pH of the decomposer composition at a temperature of 20°C is 10 or more, and the specific gravity of the decomposer composition at a temperature of 20°C is 1.03 to 1.50.

[0008] The decomposing agent composition for asphalt emulsion of the present invention comprises the following components: <1> ~ <5> It is preferable that at least one of the following conditions is satisfied. <1> The anionic surfactant (A) contains an aromatic sulfonate. <2> The organic compound (C) has at least one group selected from an oxyalkylene group and a hydroxyl group. <3> The organic compound (C) has a hydrocarbon group having 1 to 22 carbon atoms. <4> The weight proportion of the sulfur-containing anionic surfactant (A) in the decomposing agent composition is 0.1 to 40% by weight, the weight proportion of the sulfur-containing inorganic salt (B) is 0.1 to 40% by weight, and the weight proportion of the organic compound (C) is 0.1 to 20% by weight. <5> The decomposing agent composition satisfies the following condition 1. Condition 1: The weight ratio (c) of the organic compound (C) in the decomposing agent composition and the pH (R) of the decomposing agent composition at a temperature of 20° C. satisfy the following general formula (1). 0.45Rc≦5 (1)

[0009] The method for applying an asphalt pavement of the present invention includes a step of contacting the decomposer composition with an asphalt emulsion. [Effects of the Invention]

[0010] The asphalt emulsion decomposer composition of the present invention exhibits excellent decomposition properties for asphalt emulsions, has high permeability that allows separation of asphalt and water to progress to non-contact lower layer portions in a short time, and also has excellent film-forming properties for asphalt. Furthermore, the asphalt emulsion decomposer composition of the present invention can promote separation of asphalt and water in a short time, even in cases where a large amount of asphalt emulsion is sprayed. The asphalt pavement construction method of the present invention uses the asphalt emulsion decomposer composition described above, and therefore allows for efficient construction of asphalt pavements. DETAILED DESCRIPTION OF THE INVENTION

[0011] The asphalt emulsion decomposer composition of the present invention (hereinafter sometimes referred to as the decomposer composition) contains a sulfur-containing anionic surfactant (A), a sulfur-containing inorganic salt (B), an organic compound (C) having a solubility in water of 20 g / 100 g or less at 20° C., and water, and exhibits specific values ​​for pH and specific gravity at 20° C. The decomposer composition of the present invention will be described in detail below.

[0012] [Sulfur-containing anionic surfactant (A)] The sulfur-containing anionic surfactant (A) (hereinafter sometimes referred to as surfactant (A)) is an essential component of the asphalt emulsion decomposer composition of the present invention, and contains a sulfur atom in its molecule. The surfactant (A) neutralizes the charge of the cationic emulsifier present on the oil droplet surfaces of the asphalt emulsion, and because the hydrophobic group portion of the surfactant (A) has affinity for the asphalt emulsion, it breaks down the oil droplets and promotes their coalescence. When used in combination with the sulfur-containing inorganic salt (B) described below and an organic compound (C) with a solubility in water of 20 g / 100 g or less at 20°C, surfactant (A) can achieve high penetration and excellent film-forming properties for asphalt.

[0013] The surfactant (A) is not particularly limited, but examples thereof include aromatic sulfonates, aliphatic sulfonates, and organic sulfates. Examples of aromatic sulfonates include alkylbenzenesulfonates, alkoxybenzenesulfonates, naphthalenesulfonates, alkylnaphthalenesulfonates, naphthalenesulfonate-formaldehyde condensate salts, xylenesulfonates, toluenesulfonates, cumenesulfonates, and alkoxybenzenesulfonates. Examples of aliphatic sulfonates include alkyl or alkenyl sulfonates, melamine sulfonates, alkyl melamine sulfonates, melamine sulfonate-formaldehyde condensate salts, alkyl melamine sulfonate-formaldehyde condensate salts, alkyl sulfosuccinates, polyoxyalkylene alkyl ether sulfosuccinates, alkylamide sulfosuccinates, fatty acid amide sulfonates, α-sulfofatty acid methyl ester salts, acyl isethionates, and alkyl glycidyl ether sulfonates.

[0014] Examples of organic sulfates include alkyl sulfates, polyoxyalkylene alkyl ether sulfates, alkylphenyl sulfates, polyoxyalkylene alkylphenyl ether sulfates, polyoxyalkylene fatty amine sulfates, fatty acid alkanolamide sulfates, fatty acid glyceride sulfates, salts of sulfates of fats and oils, salts of sulfates of hardened fats and oils, salts of sulfates of unsaturated fatty acid esters, and salts of sulfates of olefins.

[0015] Among the surfactants (A), it is preferable to include an aromatic sulfonate salt from the viewpoint of improving the affinity with the asphalt emulsion. Among the surfactants (A), alkyl sulfates, polyoxyalkylene alkyl ether sulfates, alkylphenyl sulfates, salts of sulfates of fats and oils, salts of sulfates of unsaturated fatty acid esters, alkyl sulfosuccinates, alkyl or alkenyl sulfonates, alkylbenzenesulfonates, alkylnaphthalenesulfonates, xylenesulfonates, and alkoxybenzenesulfonates are preferred, and it is more preferred that surfactant (A) be composed of two or more of these surfactants, from the viewpoint of improving penetration and the film-forming properties of asphalt.

[0016] The salt is not particularly limited, but examples thereof include metal salts such as sodium and potassium salts; alkanolamine salts such as monoethanolamine, diethanolamine, and triethanolamine; and ammonium salts. The surfactant (A) may be composed of one or more of these salts.

[0017] The number of carbon atoms in the hydrocarbon group of the surfactant (A) is not particularly limited, but is preferably 4 to 30, more preferably 6 to 22, and even more preferably 8 to 18. When the number of carbon atoms is within the above range, affinity with the asphalt emulsion tends to be improved. The hydrocarbon group contained in the surfactant (A) may be linear or branched, and may have a cyclic structure such as an aromatic ring structure or an alicyclic structure. The hydrocarbon group contained in the surfactant (A) may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group, or may be composed of both of these groups.

[0018] When the surfactant (A) has an oxyalkylene group in the molecule, the number of carbon atoms in the oxyalkylene group is not particularly limited, but is preferably 2 to 4. When the surfactant (A) has an oxyalkylene group in the molecule, the number of moles of the oxyalkylene group added is not particularly limited, but is preferably 1 to 30. The average number of moles of oxyalkylene groups added in the surfactant (A) is not particularly limited, but is preferably 1-30.

[0019] [Sulfur-containing inorganic salt (B)] The sulfur-containing inorganic salt (B) (hereinafter sometimes referred to as inorganic salt (B)) is an essential component of the decomposer composition of the present invention and contains sulfur atoms in its molecule. The inorganic salt (B) contains sulfate ions, sulfite ions, bisulfite ions, thiosulfate ions, etc., which contribute to neutralizing the electric charge of the cationic emulsifier present on the surface of the oil droplets of the asphalt emulsion. It also adjusts the specific gravity of the decomposer composition to a specific range, and the difference in specific gravity with the asphalt emulsion promotes natural mixing, resulting in the effect that decomposition proceeds quickly not only in the surface layer that comes into contact with the asphalt emulsion upon spraying, but also in the uncontacted lower layer.

[0020] The inorganic salt (B) is not particularly limited, but is preferably water-soluble from the viewpoint of exerting the effects of the present invention. The solubility of the inorganic salt (B) in water at a temperature of 20°C is not particularly limited, but is preferably 1 g / 100 g or more. When the solubility is within the above range, the stability of the decomposing agent composition tends to be improved. The solubility is more preferably 5 g / 100 g or more, and even more preferably 10 g / 100 g or more.

[0021] The inorganic salt (B) is not particularly limited, and examples thereof include sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate, aluminum sulfate, iron sulfate, cobalt sulfate, nickel sulfate, copper sulfate, zinc sulfate, silver sulfate, zirconyl sulfate, ammonium sulfate, ammonium iron sulfate, aluminum ammonium sulfate, aluminum potassium sulfate, sodium nitrite, sodium hydrogen nitrite, sodium thiosulfate, potassium thiosulfate, magnesium thiosulfate, and ammonium thiosulfate. Among these, from the viewpoints of availability, safety, and environmental impact, at least one selected from sodium sulfate, potassium sulfate, ammonium sulfate, magnesium sulfate, and sodium thiosulfate is preferred.

[0022] [Organic compound (C)] Organic compound (C) (hereinafter sometimes referred to as organic compound (C)), which has a solubility in water of 20 g / 100 g or less at a temperature of 20°C, is an essential component of the decomposer composition of the present invention, and when the decomposer composition contains organic compound (C) exhibiting the properties described above, it is thought to function as a compatibilizer between the asphalt and surfactant (A), reducing the function of the emulsifier in the asphalt emulsion and promoting the breakdown of oil droplets, enhancing the effect of promoting asphalt coalescence. Furthermore, phase separation and solid precipitation in the decomposer composition are suppressed, improving stability and enabling the decomposer composition to be sprayed evenly. The organic compound (C) is one other than the surfactant (A).

[0023] The solubility of the organic compound (C) in water at a temperature of 20° C. is 20 g / 100 g or less, preferably 15 g / 100 g or less, and more preferably 10 g / 100 g or less. The lower limit of the solubility is 0 g / 100 g. The organic compound (C) may be solid or liquid at a temperature of 20° C. There are no particular limitations on the organic compound (C), but from the viewpoint of exerting the effects of the present invention, it is preferable that the organic compound (C) is liquid at a temperature of 20° C.

[0024] The organic compound (C) is not particularly limited, but from the viewpoint of affinity with the surfactant (A), it preferably has at least one group selected from an oxyalkylene group and a hydroxyl group. The number of carbon atoms in the oxyalkylene group of the organic compound (C) is not particularly limited, but is preferably 2-4, and more preferably 2-3. The number of moles of oxyalkylene groups added in the organic compound (C) is not particularly limited, but is preferably 1-50, more preferably 1-40, even more preferably 1-30, and particularly preferably 1-20. The average number of moles of oxyalkylene groups added in the organic compound (C) is not particularly limited, but is preferably 1-50, more preferably 1-40, even more preferably 1-30, and particularly preferably 1-20. When the organic compound (C) has oxyalkylene groups with different numbers of carbon atoms, the oxyalkylene groups may be added randomly or in a block form.

[0025] The number of hydroxyl groups in the organic compound (C) is not particularly limited, but is preferably 1-10, more preferably 1-6, even more preferably 1-4, and particularly preferably 1-3.

[0026] The organic compound (C) is not particularly limited, but from the viewpoint of improving affinity with the asphalt emulsion and the surfactant (A), it preferably has a hydrocarbon group having 1 to 22 carbon atoms. The number of carbon atoms in the hydrocarbon group is more preferably 1 to 20, even more preferably 1 to 18, and particularly preferably 1 to 12. The hydrocarbon group is not particularly limited, but examples thereof include alkyl groups, cycloalkyl groups, alkenyl groups, alkynyl groups, aryl groups, allyl groups, and vinyl groups. When the organic compound (C) has the above-mentioned hydrocarbon group, the hydrocarbon group may be linear or branched, and may have a cyclic structure such as an aromatic ring structure or an alicyclic structure. The hydrocarbon group contained in the organic compound (C) may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group, or may be composed of these two types.

[0027] The organic compound (C) is not particularly limited as long as its solubility in water at a temperature of 20°C is 20 g / 100 g or less. Examples thereof include polyoxyalkylene alkyl ethers such as polyoxyalkylene methyl ether, polyoxyalkylene ethyl ether, polyoxyalkylene propyl ether, polyoxyalkylene butyl ether, polyoxyalkylene hexyl ether, polyoxyalkylene octyl ether, polyoxyalkylene lauryl ether, polyoxyalkylene myristyl ether, polyoxyalkylene oleyl ether, polyoxyalkylene stearyl ether, polyoxyalkylene benzyl ether, polyoxyalkylene dibutyl ether, polyoxyalkylene dihexyl ether, polyoxyalkylene dioctyl ether, polyoxyalkylene dilauryl ether, polyoxyalkylene dioleyl ether, and polyoxyalkylene distearyl ether; polyoxyalkylene phenyl ether, polyoxyalkylene alkylphenyl ether, and polyoxyalkylene dialkylphenyl ether. polyoxyalkylene aryl ethers such as styrene ether, polyoxyalkylene styrenated phenyl ether, polyoxyalkylene distyrenated phenyl ether, and polyoxyalkylene tristyrenated phenyl ether; polyoxyalkylene glycols such as polypropylene glycol and polyoxyethylene polyoxypropylene glycol, polyoxyalkylene glyceryl ether, polyoxyalkylene trimethylolpropane, polyoxyalkylene pentaerythritol, and 2,2-bis(4-polyoxyalkyleneoxyphenyl)propane; fatty acid esters such as polyoxyalkylene fatty acid esters, polyoxyalkylene fatty acid diesters, polyoxyalkylene glyceryl ether fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, glycerin fatty acid esters, and sorbitan fatty acid esters; alcohols such as butyl alcohol, octyl alcohol, lauryl alcohol, oleyl alcohol, stearyl alcohol, and pentaerythritol;Examples thereof include phenols such as phenol, alkylphenols, alkoxyphenols, styrenated phenol, distyrenated phenol, tristyrenated phenol, and 2,2-bis(4-hydroxyphenyl)propane; amines such as alkylamines, polyoxyalkylene alkylamines, and polyoxyalkylene ethylenediamines; and fatty acid amides such as fatty acid amides and polyoxyalkylene fatty acid amides, and these may be used alone or in combination of two or more.

[0028] The organic compound (C) is not particularly limited, but from the viewpoint of exerting the effects of the present invention, it is preferably at least one selected from polyoxyalkylene polyols and organic compounds having at least one group selected from an oxyalkylene group and a hydroxyl group and having a hydrocarbon group having 1 to 22 carbon atoms.

[0029] The molecular weight of the organic compound (C) is not particularly limited, but is preferably 3000 or less. When the molecular weight is 3000 or less, the stability of the decomposing agent composition is improved, and phase separation and precipitation of solids tend to be further suppressed. The upper limit of the molecular weight is more preferably 2500 or less, even more preferably 2000 or less, particularly preferably 1500 or less, and most preferably 1000 or less. On the other hand, the lower limit of the molecular weight is 90. When the organic compound (C) has a repeating unit such as the oxyalkylene group in its molecule, the molecular weight is the weight average molecular weight (Mw). The weight average molecular weight (Mw) of the organic compound (C) is measured by the method described in the Examples.

[0030] 〔water〕 The water contained in the decomposing agent composition of the present invention is not particularly limited, and may be, for example, tap water, ion-exchanged water, distilled water, etc. From the viewpoint of water hardness, soft water is preferred.

[0031] The decomposing agent composition of the present invention may contain other components in addition to the surfactant (A), the inorganic salt (B), the organic compound (C), and water, as needed. Examples of other components include basic compounds other than the organic compound (C) (hereinafter sometimes referred to as basic compounds), water-soluble solvents having a solubility in water at a temperature of 20°C of more than 20 g / 100 g, surfactants other than the surfactant (A) and the organic compound (C), and antifoaming agents.

[0032] The basic compound is not particularly limited, and examples thereof include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; silicates such as sodium orthosilicate, sodium metasilicate, No. 1 sodium silicate, No. 2 sodium silicate, No. 3 sodium silicate, No. 4 sodium silicate, No. 5 sodium silicate, potassium silicate, and magnesium silicate; carbonates such as lithium carbonate, sodium carbonate, and potassium carbonate; metal salts of monobasic acids having a solubility in water at a temperature of 20°C of more than 20 g / 100 g, such as potassium caprate, potassium oleate, potassium laurate, potassium coconut fatty acid, potassium tallow fatty acid, potassium castor oil fatty acid, and potassium naphthenate (hereinafter sometimes referred to as water-soluble metal salts of monobasic acids); dipotassium oxalate, disodium adipate, disodium pimelate, disodium suberate, dipotassium sebacate, dipotassium undecanoate, dipotassium dodecanoate, trisodium citrate, sodium carboxymethylcellulose, and polymethacrylic acid. Examples of suitable water-soluble amines include metal salts of polycarboxylic acids, such as sodium, having a solubility in water of more than 20 g / 100 g at 20° C.; metal salts of aromatic carboxylic acids, such as sodium benzoate, calcium benzoate, sodium phthalate, sodium terephthalate, sodium hydroxybenzoate, sodium salicylate, sodium anisate, and sodium cinnamate, having a solubility in water of more than 20 g / 100 g at 20° C.; and water-soluble amines (hereinafter sometimes referred to as water-soluble amines), having a solubility in water of more than 20 g / 100 g at 20° C., such as monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, alkylamines, alkylmonoethanolamines, dialkylethanolamines, polyoxyalkylenedialkylamines, alkyldiethanolamines, polyoxyalkylenealkylamines, ethylenediamine, polyoxyalkyleneethylenediamine, diethylenetriamine, morpholine, and piperazine. These may be used alone or in combination of two or more. The weight average molecular weight (Mw) of the water-soluble amines is not particularly limited, but is preferably 1,000 or less, more preferably 600 or less, and even more preferably 400 or less. The basic compound is not particularly limited, but from the viewpoint of exerting the effects of the present invention, it is preferable that the basic compound is at least one selected from alkali metal hydroxides, silicates, metal salts of water-soluble monobasic acids, and water-soluble amines.

[0033] The water-soluble solvent having a solubility in water of more than 20 g / 100 g at a temperature of 20°C (hereinafter sometimes referred to as water-soluble solvent) is not particularly limited, but examples thereof include methanol, ethanol, propanol, ethylene glycol, diethylene glycol, propylene glycol, 2-ethoxyethanol, 2-(2-ethoxyethoxy)ethanol, 2-butoxyethanol, 2-(2-butoxyethoxy)ethanol, 3-methoxy-3-methyl-1-butanol, glycerin, dimethylformamide, dimethyl sulfoxide, and the like, and one or more of these may be used in combination.

[0034] The surfactant other than the surfactant (A) and the organic compound (C) is not particularly limited, and examples thereof include anionic surfactants such as alkyl phosphate ethers and carboxylates, cationic surfactants, amphoteric surfactants, and nonionic surfactants having a solubility in water at 20°C of more than 20 g / 100 g, and one or more of these may be used in combination. The antifoaming agent is not particularly limited, but examples thereof include ester-based antifoaming agents, polyether-based antifoaming agents, mineral oil-based antifoaming agents, silicone-based antifoaming agents, powder antifoaming agents, and the like, and one or more of these may be used in combination.

[0035] [Asphalt emulsion decomposer composition and its manufacturing method] The pH of the decomposing composition of the present invention at a temperature of 20°C is 10 or higher. If the pH is 10 or higher, neutralization of the charge of the emulsifier present on the oil droplet surface of the asphalt emulsion is promoted, and decomposition progresses to the non-contact lower layer portion in a short time. The preferred upper limit of the pH is 14. The pH of the decomposing composition of the present invention at a temperature of 20°C is determined by the method described in the Examples. When adjusting the pH of the decomposing agent composition at a temperature of 20°C to fall within the above range, the above basic compound may be contained.

[0036] The specific gravity of the decomposer composition of the present invention at a temperature of 20°C is 1.03 to 1.50. If the specific gravity is less than 1.03, decomposition does not progress to the non-contact lower layer portion. If the specific gravity exceeds 1.50, the decomposition ability of the asphalt emulsion at low temperatures decreases. The specific gravity is preferably 1.03 to 1.40, more preferably 1.05 to 1.30. The specific gravity of the decomposing composition of the present invention at a temperature of 20°C is determined by the method described in the Examples.

[0037] The viscosity of the decomposing agent composition of the present invention at a temperature of 20°C is not particularly limited, but is preferably 0.1 to 500 mPa·s, more preferably 0.1 to 400 mPa·s, even more preferably 0.1 to 300 mPa·s, and particularly preferably 0.1 to 200 mPa·s. When the viscosity is within the above range, the decomposing agent composition can be sprayed more uniformly over a wider area, and furthermore, after spraying, the decomposing agent composition tends to be more easily mixed with the asphalt emulsion, improving the penetration of the decomposing agent composition into the asphalt emulsion. The viscosity of the decomposing agent composition of the present invention at 20° C. can be measured using, for example, a Brookfield viscometer.

[0038] The surface tension of the decomposing composition of the present invention at an effective concentration of 0.5% by weight at a temperature of 25° C. is not particularly limited, but is preferably 0.1 to 55 mN / m, more preferably 0.1 to 50 mN / m, even more preferably 0.1 to 45 mN / m, and particularly preferably 0.1 to 40 mN / m. If the surface tension is within the above range, the permeability of the decomposing composition into the asphalt emulsion tends to improve, and further, uneven decomposition due to uneven application tends to be reduced. The surface tension of the decomposing composition of the present invention at an effective concentration of 0.5% by weight at a temperature of 25° C. can be measured by, for example, the Wilhelmy plate method.

[0039] The weight proportion of the surfactant (A) in the decomposing agent composition of the present invention is not particularly limited, but is preferably 0.1 to 40% by weight, more preferably 1 to 30% by weight, even more preferably 5 to 25% by weight, and particularly preferably 8 to 25% by weight. When the weight proportion is within the above range, permeability and film-forming properties of asphalt tend to be improved.

[0040] The weight proportion of the inorganic salt (B) in the decomposing agent composition of the present invention is not particularly limited, but is preferably 0.1 to 40% by weight, more preferably 1 to 30% by weight, and even more preferably 2 to 25% by weight. When the weight proportion is within the above range, permeability tends to be improved.

[0041] The weight proportion of the organic compound (C) in the decomposing agent composition of the present invention is not particularly limited, but is preferably 0.1 to 20% by weight, more preferably 0.5 to 15% by weight, even more preferably 1 to 12% by weight, and particularly preferably 2 to 10% by weight. When the weight proportion is within the above range, permeability and film-forming properties of asphalt tend to be improved.

[0042] As described above, the decomposing agent composition of the present invention contains water. The form of the decomposing agent composition of the present invention is not particularly limited, and may be in the form of an aqueous solution, or may be in the form of an emulsified or dispersed in water, or may be in the form of an emulsified, dispersed or solubilized. The weight proportion of water in the decomposer composition of the present invention is not particularly limited, but is preferably 10 to 90% by weight, more preferably 15 to 85% by weight, even more preferably 20 to 80% by weight, and particularly preferably 30 to 80% by weight. Within the above ranges, the stability of the decomposer composition tends to be improved, and it tends to be possible to spray it uniformly over a wide area. The weight ratio of water in the decomposing agent composition is determined by the method described in the Examples.

[0043] The decomposing agent composition for the asphalt emulsion of the present invention is not particularly limited, but from the viewpoint of improving permeability and film-forming properties of asphalt, it is preferable that the weight ratio (c) of the organic compound (C) in the decomposing agent composition and the pH (R) of the decomposing agent composition at 20°C satisfy the following general formula (1): 0.45Rc≦5 (1) The upper limit of the numerical range of the general formula (1) is more preferably 4, even more preferably 3, and particularly preferably 2. The lower limit of the numerical range of the general formula (1) is preferably −15.

[0044] The asphalt emulsion decomposer composition of the present invention contains the surfactant (A), the inorganic salt (B), the organic compound (C), and water, and exhibits a specific pH and specific gravity. It exhibits excellent decomposition properties for asphalt emulsions, and also has high permeability, allowing separation of asphalt and water to proceed even to non-contact areas in a short period of time, and excellent asphalt film-forming properties. The decomposing agent composition of the present invention is particularly effective in decomposing cationic asphalt emulsions, such as the cationic asphalt emulsion "PK-4" specified in JIS-K2208 and "PKM-T" and "PKM-TQ" specified in the Japan Asphalt Emulsion Association Standard JEAAS.

[0045] The decomposing agent composition of the present invention may be produced by, but is not particularly limited to, a method of mixing the surfactant (A), the inorganic salt (B), the organic compound (C), and water with other components such as a basic compound as needed, or a method of preparing a mixed solution in which the surfactant (A), the inorganic salt (B), and the organic compound (C) are dissolved or dispersed in water at a high concentration in advance, and then adding other components such as a basic compound to the prepared mixed solution as needed, followed by mixing. In the method for producing the decomposing composition, the mixing order, etc. is not particularly limited, and all components may be mixed at the same time, or each component may be mixed in turn, or some components may be mixed in advance, and the remaining components or a mixture thereof may be added to the obtained mixture, mixed, dispersed, or dissolved. There are no particular limitations on the mixing method, and the mixing can be carried out using an apparatus equipped with an extremely simple mechanism such as a container and a stirring blade.

[0046] [Asphalt pavement construction method] The method for applying an asphalt pavement of the present invention includes a step of contacting the decomposer composition with an asphalt emulsion. The decomposing agent composition may be sprayed simultaneously with the asphalt emulsion to bring the decomposing agent composition and the asphalt emulsion into contact with each other, or the asphalt emulsion may be sprayed first and then the decomposing agent composition may be sprayed on top of it to bring the decomposing agent composition and the asphalt emulsion into contact with each other. The decomposing agent composition and the asphalt emulsion may be heated before spraying.

[0047] Asphalt emulsions are sprayed onto road subgrades, base layers, and surface layers, and are also used for spray-on waterproofing of slopes, walls, etc., and since the decomposer composition has excellent decomposability, it can also be used for these applications. When spraying the decomposing agent composition, it is preferable to spray it in the form of a mist to ensure uniformity. For small-scale paving, an engine sprayer, gear sprayer, air sprayer, hand sprayer, airless pump sprayer, etc. may be used, and for large-scale paving, a device for spraying asphalt emulsion, such as an asphalt sprayer, asphalt distributor, or asphalt finisher with an emulsion spraying function, may be used. There is no particular limitation on the amount of the decomposing agent composition to be sprayed, but it is preferably 10 parts by weight or more per 100 parts by weight of the asphalt emulsion. [Example]

[0048] The present invention will be specifically described below with reference to examples and comparative examples. The present invention is not limited to these examples. In the following examples and comparative examples, "%" means "% by weight" and "parts" means "parts by weight" unless otherwise specified. Furthermore, hereinafter, the asphalt emulsion decomposer composition may be referred to as the "decomposer composition." Furthermore, the solubility in water at a temperature of 20°C may be referred to as the "solubility," the pH at a temperature of 20°C may be referred to as the "pH," and the specific gravity at a temperature of 20°C may be referred to as the "specific gravity." The physical properties and performance of the decomposing agent compositions in the following Examples and Comparative Examples were evaluated by the methods shown below.

[0049] [Production of decomposition agent composition] The decomposing agent compositions of Examples 1 to 14 and Comparative Examples 1 to 6 were produced so as to have the weight ratios shown in Tables 1 and 2. The physical properties of the produced decomposing agent compositions were measured. The results are shown in Tables 1 and 2. Furthermore, a test was conducted on the decomposition ability of the prepared decomposition composition on asphalt emulsion. The results are shown in Table 3.

[0050] [Method for measuring specific gravity] The specific gravity of the decomposing agent composition at a temperature of 20°C was measured using the following density / specific gravity meter as a measuring device according to the method in accordance with JIS Z8804-9. Density and specific gravity meter: Kyoto Electronics Manufacturing Co., Ltd. DA-200

[0051] [pH measurement method] The pH of the decomposing agent composition at a temperature of 20°C was measured using the following glass electrode pH meter as a measuring device. Glass electrode pH meter: Horiba, Ltd., tabletop pH meter F-71

[0052] [Method for measuring the weight percentage of water] The weight proportion of water in the decomposing agent composition was measured by volumetric titration in accordance with JIS K0068 using the following Karl Fischer titrator as a measuring instrument. Karl Fischer titrator: Kyoto Electronics Manufacturing MKA-510N The effective concentration of the decomposing agent composition in the present invention refers to the weight ratio obtained by excluding the weight ratio of water measured by the above method from the total weight of the decomposing agent composition.

[0053] [Method for measuring weight average molecular weight] The weight average molecular weight (Mw) of the organic compound (C) was measured by gel permeation chromatography (GPC) using the following method. The organic compound (C) was dissolved in tetrahydrofuran to a concentration of approximately 0.2 wt % to prepare an eluent. The weight-average molecular weight of the organic compound (C) was measured using the prepared eluent under the following conditions. Polyethylene glycol with a known molecular weight was used to create a calibration curve. Device name: HLC-8220 (Tosoh Corporation) Columns: KF-G, KF-402HQ, and KF-403HQ connected in series (all manufactured by Shodex) Eluent: tetrahydrofuran Injection volume: 10μL Eluent flow rate: 0.3 mL / min Temperature: 40℃

[0054] [Asphalt emulsion decomposition test] On a slate board measuring 150mm long x 150mm wide x 3mm thick, 0.4L / m of cationic asphalt emulsion PK-4 was applied. 2 The test base was prepared by uniformly applying the above mixture and letting it air-dry. The test base was cured in a thermostatic chamber at 5°C for at least 4 hours, and the cationic asphalt emulsion and decomposer composition were cured in a thermostatic chamber at 20°C for at least 4 hours. A predetermined amount of cationic asphalt emulsion PK-4 was applied to the cured test base, and then 10% by weight of the decomposer composition of the asphalt emulsion was quickly sprayed on top of it using a sprayer. The test base was then returned to the thermostatic chamber at 5°C and allowed to stand. The state of decomposition of the emulsion was checked visually and by touch after 1 minute, 3 minutes, 5 minutes and 10 minutes immediately after the start of the test. ○ Asphalt has formed a film and is decomposed down to the lower layer △1 Decomposed and filmed, but undecomposed emulsion remains △2 Decomposition to the lower layer has not occurred, and the aggregates have settled × Asphalt does not form a film and undecomposed emulsion remains If the asphalt emulsion decomposed to the lower layer within 10 minutes and formed a film, it was considered to have passed. If the asphalt emulsion remained without decomposing even after 10 minutes, or if the separated asphalt did not form a film, it was considered to have failed.

[0055] The molecular weights and solubilities (g / 100g) in 100g of water at a temperature of 20°C of the compounds shown in Tables 1 and 2 are as follows. POP(1) butyl ether Molecular weight: 132 Solubility: 6.8 POE(1) Lauryl Ether Weight average molecular weight: 234, Solubility: less than 0.1 POP(3) phenyl ether Weight average molecular weight: 268 Solubility: less than 0.1 Monoethanolamine Molecular weight: 61 Solubility: over 20 Ethyldiethanolamine Molecular weight: 133 Solubility: over 20 Butyldiethanolamine Molecular weight: 161 Solubility: over 20 Glycerin Molecular weight: 92 Solubility: over 20 POE(2) butyl ether Molecular weight: 162 Solubility: over 20 In Tables 1 and 2, POE means polyoxyethylene, and POP means polyoxypropylene. The numbers in parentheses following POE or POP indicate the number of moles of oxyethylene or oxypropylene added. In Tables 1 and 2, Na means sodium salt, K means potassium salt, and Mg means magnesium salt.

[0056] [Table 1]

[0057] [Table 2]

[0058] [Table 3]

[0059] As can be seen from Tables 1 to 3, the decomposer compositions of Examples 1 to 14 contain a surfactant (A), an inorganic salt (B), an organic compound (C), and water, and the pH of the decomposer composition at a temperature of 20°C is 10 or higher, and the specific gravity of the decomposer composition at a temperature of 20°C is 1.03 to 1.50, thereby solving the problem of the present invention. On the other hand, when the decomposer composition does not contain at least one of the surfactant (A), the inorganic salt (B), and the organic compound (C) (Comparative Examples 1 to 3, 6), when the pH of the decomposer composition at a temperature of 20°C is less than 10 (Comparative Example 4), or when the specific gravity of the decomposer composition at a temperature of 20°C is less than 1.03 (Comparative Example 5), the problem of the present invention cannot be solved.

Claims

1. A composition for decomposing an asphalt emulsion, comprising a sulfur-containing anionic surfactant (A), a sulfur-containing inorganic salt (B), an organic compound (C) having a solubility in water at a temperature of 20°C of 20 g / 100 g or less, and water, the pH of the decomposing agent composition at a temperature of 20°C is 10 or more, The specific gravity of the decomposing agent composition at a temperature of 20°C is 1.03 to 1.

50. Asphalt emulsion breaker composition.

2. The decomposing agent composition according to claim 1 , wherein the anionic surfactant (A) comprises an aromatic sulfonate.

3. 3. The decomposing agent composition according to claim 1, wherein the organic compound (C) has at least one group selected from an oxyalkylene group and a hydroxyl group.

4. The decomposing agent composition according to claim 1 or 2, wherein the organic compound (C) has a hydrocarbon group having 1 to 22 carbon atoms.

5. 3. The decomposer composition according to claim 1, wherein the weight ratio of the sulfur-containing anionic surfactant (A) in the decomposer composition is 0.1 to 40% by weight, the weight ratio of the sulfur-containing inorganic salt (B) is 0.1 to 40% by weight, and the weight ratio of the organic compound (C) is 0.1 to 20% by weight.

6. The decomposing agent composition according to claim 5, which satisfies the following condition 1: Condition 1: The weight ratio (c) of the organic compound (C) in the decomposing composition and the pH (R) of the decomposing composition at a temperature of 20° C. satisfy the following general formula (1). 0.45R-c≦5 (1)

7. A method for constructing an asphalt pavement, comprising a step of contacting the decomposer composition according to claim 1 or 2 with an asphalt emulsion.

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