JP6690945B2 - Asphalt emulsion decomposer - Google Patents

Description

  The present invention relates to an asphalt emulsion decomposing agent. More specifically, the present invention relates to a cationic asphalt emulsion decomposing agent for permeation, which is used for tack coat, prime coat and the like.

Asphalt is the final refined product obtained after distilling petroleum to extract naphtha, gasoline, kerosene, light oil, etc., and has been used for paving materials since ancient times.
Asphalt is a semi-solid or solid with high viscosity at room temperature, and its workability during handling is extremely poor due to its high adhesiveness.
As one of the methods for improving the workability at the time of handling at room temperature, it is known to use asphalt in the form of being emulsified in water using an emulsifier, and the emulsion is called an asphalt emulsion.
There are two main methods for classifying asphalt emulsions, one is classified into cationic, anionic, nonionic, etc. depending on the emulsifier used, and the other is classified into permeation, mixing, etc. depending on the application. There is a way to do it.
The main applications of infiltration asphalt emulsions are prime coats, which are used for surface finishing after asphalt paving, and tack coats, which are used for interlayer adhesion between a base layer and an asphalt layer to be newly laid.
According to the Japanese Industrial Standard JIS K 2208, the asphalt emulsion for penetration "PK-4" is generally used for tack coat. In recent years, asphalt pavement repair and re-pavement have been increasing, and the use of PK-4 has been increasing.
Required properties of asphalt emulsion are storage stability from the time of production of asphalt emulsion to use at the construction site, and emulsification even when external force such as shear or compression by a pump used during transfer or dispersion of emulsion is applied. The mechanical stability is not broken.
Furthermore, it is strongly desired that the asphalt emulsion is sprayed at the construction site and then decomposed in the shortest possible time to quickly separate it into water and asphalt.
This is because if moisture remains in the asphalt, the original tackiness of the asphalt cannot be obtained, resulting in poor adhesion, but generally, after spraying the asphalt emulsion, the moisture in the agent evaporates until it is sufficiently decomposed. This is due to the fact that it is necessary to wait, and during that time it is necessary to regulate the passage of roads and it takes time to open the passage.

In order to impart such characteristics that are contrary to storage stability and mechanical stability, a method is known in which a decomposing agent that destroys the emulsification when using an asphalt emulsion is added, and then only the separated water is removed.
Sodium hydroxide and aggregates are known as decomposers for cationic asphalt emulsions.
However, sodium hydroxide is a deleterious substance, and there are problems in terms of environment and worker safety when used on actual roads. Aggregates greatly differ in the decomposition effect depending on the shape and the components contained therein, and a great deal of labor and time are required to select an aggregate suitable for the asphalt emulsion to be used.

Patent Documents 1 and 2 disclose a spraying method in which a cationic metal-based asphalt emulsion using an emulsifier containing amine as a main constituent is used and a light metal electrolyte decomposing agent is brought into contact with the asphalt emulsion after spraying.
However, these cannot completely solve the above problems, and there are problems that the asphalt emulsion having high storage stability and mechanical stability is not sufficiently decomposed or that decomposition takes time.

Patent Documents 3 and 4 exemplify anionic surfactants and the like as decomposition aids. However, only the part where the asphalt emulsion and the decomposition aid come into contact with each other is decomposed, and the non-contact part is not decomposed and remains asphalt emulsion. As a result, there is a problem that it may cause adhesion failure, or decomposed asphalt may form a film on the surface to prevent evaporation of moisture in the lower layer, resulting in a longer time until traffic is released.
In addition, depending on the actual temperature of the construction site, sunshine, the presence of wind, etc., a sufficient effect may not be obtained.

Japanese Patent Laid-Open No. 11-302546 Japanese Patent Laid-Open No. 11-303004 JP, 9-21102, A JP 2000-336602 A

  INDUSTRIAL APPLICABILITY The present invention has excellent storage stability and immediate decomposability of a cationic asphalt emulsion having high mechanical stability. The purpose is to provide a decomposing agent that progresses.

As a result of intensive studies, the present inventors have found that it is a decomposing agent for a cationic asphalt emulsion containing a sulfur-containing anionic surfactant and an inorganic sulfate and / or a condensed phosphate and having a specific gravity. Therefore, they have found that the above problems can be solved, and have reached the present invention.
That is, the decomposing agent for the cationic asphalt emulsion of the present invention contains a sulfur-containing anionic surfactant and an inorganic sulfate and / or condensed phosphate, and has a specific gravity of 1.03 to 1.15 at 20 ° C. And the viscosity at 20 ° C. is 0.1 mPa · s or more and 121 mPa · s or less.

It is preferable that the specific gravity at 20 ° C. is 1.04 to 1.15, and the viscosity at 20 ° C. is 11.1 to 121 mPa · s .
It is preferable that the sulfur-containing anionic surfactant contains at least one selected from alkyl sulfonic acid, alkyl sulfonate, alkylbenzene sulfonic acid and alkylbenzene sulfonate.
The sulfur-containing anionic surfactant is at least one selected from dialkylsulfosuccinic acid, dialkylsulfosuccinate, sulfates of fats and oils, sulfates of fats and oils, sulfates of hardened fats and oils and sulfates of hardened fats and oils. It is preferable to further include
The inorganic sulfate preferably contains at least one selected from ammonium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate and iron sulfate.
The condensed phosphate preferably contains at least one selected from pyrophosphate and tripolyphosphate.
The weight ratio of the sulfur-containing anionic surfactant is 0.1 to 30.0 parts by weight, and the weight ratio of the inorganic sulfate and / or the condensed phosphate is 0.1 to 50 parts by weight with respect to 100 parts by weight of the decomposer. It is preferably 0.0 part by weight.
The cationic asphalt emulsion is preferably "PK-4" defined in Japanese Industrial Standard JIS K2208.

  The method for spraying an asphalt emulsion of the present invention is a method for spraying a cationic asphalt emulsion with the above decomposing agent.

  The cationic asphalt emulsion decomposing agent of the present invention is brought into contact with the cationic asphalt emulsion to rapidly decompose immediately after separation, and water and asphalt are separated, and are rapidly mixed with the asphalt emulsion and contacted at the time of spraying. Not even the internal asphalt emulsion has the effect of breaking down. Also, there is little influence on the decomposition effect due to the temperature, sunshine, presence of wind, etc. at the construction site, and after the decomposition, you can immediately proceed to the next process by removing the separated water, and the effect that the construction time is greatly shortened Have.

  The decomposing agent for the cationic asphalt emulsion of the present invention contains a sulfur-containing anionic surfactant and an inorganic sulfate and / or condensed phosphate, and has a specific gravity at 20 ° C of a specific value. The details will be described below.

(Sulfur-containing anionic surfactant)
The sulfur-containing anionic surfactant is an essential component of the decomposing agent for the cationic asphalt emulsion of the present invention, neutralizes the charge of the cationic emulsifier present on the oil droplet surface of the asphalt emulsion, and also serves as a hydrophobic group moiety. Has an affinity with the asphalt emulsion, it plays a role of breaking the oil droplets and promoting coalescence. By using the sulfur-containing anionic surfactant in combination with the inorganic sulfate and / or condensed phosphate described below, the cationic asphalt emulsion is excellent in immediate decomposability, and the decomposition progresses to the lower non-contact layer. The effect of doing can be obtained.

  Examples of the sulfur-containing anionic surfactant include alkyl or alkenyl sulfonic acid, alkyl or alkenyl sulfonic acid salt, alkylbenzene sulfonic acid, alkylbenzene sulfonic acid salt, naphthalene sulfonic acid, naphthalene sulfonic acid salt, alkylnaphthalene sulfonic acid, alkylnaphthalene sulfonic acid. Acid salt, naphthalene sulfonic acid formalin condensate, naphthalene sulfonic acid formalin condensate salt, melamine sulfonic acid, melamine sulfonate, alkyl melamine sulfonic acid, alkyl melamine sulfonate, melamine sulfonic acid formalin condensate, melamine sulfonic acid formalin condensation Product salt, alkyl melamine sulfonic acid formalin condensate, alkyl melamine sulfonic acid formalin condensate salt, alkyl sulfosuccinic acid, alkyl sulfosuccinate, Fatty acid amide sulfonic acid, fatty acid amide sulfonate, alkyl sulfate, alkyl sulfate, polyoxyalkylene alkyl ether sulfate, polyoxyalkylene alkyl ether sulfate, alkylphenyl sulfate, alkylphenyl sulfate, polyoxyalkylene alkylphenyl ether sulfate , Polyoxyalkylene alkyl phenyl ether sulfates, sulfates of fats and oils, salts of sulfates of fats and oils, sulfates of hardened fats and oils, sulfates of hardened fats and oils, among others, from the viewpoint of exerting the effect of the present application. , Alkyl sulfonates, alkyl benzene sulfonates, alkyl sulfosuccinates, and salts of fats and oils sulfates are preferable.

The alkyl group of the alkyl sulfonic acid preferably has 4 to 30 carbon atoms, more preferably 6 to 22 and even more preferably 8 to 18 carbon atoms. If it is less than 4, the immediate degradability may be poor. If it exceeds 30, hydrophilicity may be deteriorated and it may be difficult to adjust the decomposing agent.
The alkyl group of the alkylsulfonic acid may be linear or branched, and may have a distribution in the alkyl group.
The alkyl sulfonic acid is not particularly limited, for example, pentane sulfonic acid, hexane sulfonic acid, heptane sulfonic acid, octane sulfonic acid, decane sulfonic acid, dodecane sulfonic acid, tetradecane sulfonic acid, hexadecane sulfonic acid, octadecane sulfonic acid, ico Examples thereof include sun sulfonic acid and henicosane sulfonic acid.

  The salt of the organic sulfonic acid is not particularly limited, and examples thereof include sodium salt, potassium salt, magnesium salt, calcium salt, aluminum salt, monoethanolamine salt, diethanolamine salt, triethanolamine salt or ammonium salt. Among them, sodium salts, potassium salts, and ammonium salts are preferable from the viewpoint of easy availability, safety, and influence on the environment.

  Examples of the alkylbenzenesulfonic acid include octylbenzenesulfonic acid, decylbenzenesulfonic acid, dodecylbenzenesulfonic acid, xylenesulfonic acid, toluenesulfonic acid, cumenesulfonic acid and the like.

  Examples of the alkylsulfosuccinic acid include dioctylsulfosuccinic acid, didecylsulfosuccinic acid, didodecylsulfosuccinic acid, ditridecylsulfosuccinic acid, octylsulfosuccinic acid, decylsulfosuccinic acid, dodecylsulfosuccinic acid and tridecylsulfosuccinic acid.

(Inorganic sulfate and / or condensed phosphate)
The inorganic sulfate and / or the condensed phosphate is an essential component of the decomposing agent for the cationic asphalt emulsion of the present invention, and is a cationic emulsifier in which sulfate ions and condensed phosphate ions are present on the oil droplet surface of the asphalt emulsion. It contributes to neutralize the electric charge and can adjust the specific gravity of the decomposing agent to a specific range.The difference in specific gravity from the asphalt emulsion sprayed earlier promotes natural mixing, and only the surface layer part that comes into contact during spraying In addition, it is possible to obtain the effect that the decomposition rapidly progresses to the lower layer portion which is not in contact.

Inorganic sulfates 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. , Potassium aluminum sulfate and the like.
Of these, sodium sulfate, potassium sulfate, and ammonium sulfate are preferable because of their easy availability, safety, and environmental impact.

As the condensed phosphate, sodium pyrophosphate, potassium pyrophosphate, copper pyrophosphate, tin pyrophosphate, disodium dihydrogen pyrophosphate, calcium hydrogen pyrophosphate, sodium tripolyphosphate, potassium tripolyphosphate, sodium tetrapolyphosphate, hexametaphosphoric acid Examples thereof include sodium and potassium metaphosphate.
Among them, sodium pyrophosphate, potassium pyrophosphate and sodium tripolyphosphate are preferable from the viewpoint of easy availability and exerting the effect of the present application.

[Cationic asphalt emulsion decomposer]
The specific gravity of the decomposing agent of the cationic asphalt emulsion of the present invention at 20 ° C is 1.03 to 2.00, preferably 1.03 to 1.80, more preferably 1.03 to 1.60, and 1.03. ˜1.40 is more preferable, and 1.03 to 1.30 is particularly preferable. If it is less than 1.03, the decomposition does not proceed to the lower non-contact layer. On the other hand, if it exceeds 2.00, the stability of the decomposing agent solution may be lowered, and uniform spraying may become difficult, or the immediate decomposing property may be deteriorated.

The viscosity of the decomposing agent of the cationic asphalt emulsion of the present invention at 20 ° C. is preferably 500 mPa · S or less, more preferably 400 mPa · S or less, further preferably 300 mPa · S or less, and particularly preferably 200 mPa · S or less. If it exceeds 500 mPa · S, it becomes difficult to mix it with the asphalt emulsion at the time of spraying the decomposer, and the decomposition may not proceed to the lower non-contact layer.
A preferable lower limit value is 0.1 mPa · S. If it is less than 0.1 mPa · S, it becomes difficult to mix with the asphalt emulsion, and the decomposition may not proceed to the lower layer portion which is not in contact.

The weight ratio of the sulfur-containing anionic surfactant in the decomposer of the cationic asphalt emulsion of the present invention is preferably 0.1 to 30.0% by weight, more preferably 0.5 to 20.0% by weight. 0.0 to 15.0% by weight is more preferable, and 1.0 to 10.0% by weight is particularly preferable. If it is less than 0.1% by weight, the immediate decomposability may be poor. If it exceeds 30.0% by weight, the stability of the decomposing agent solution may be lowered, and uniform spraying may become difficult.
The weight ratio of the inorganic sulfate and / or the condensed phosphate in the decomposer of the cationic asphalt emulsion of the present invention is preferably 0.1 to 50.0% by weight, more preferably 1.0 to 40.0% by weight. 3.0 to 35.0% by weight is more preferable, and 5.0 to 30.0% by weight is particularly preferable. If it is less than 0.1% by weight, the decomposition may not proceed to the lower non-contact layer. If it exceeds 50.0% by weight, the stability of the decomposing agent solution may be lowered, and uniform spraying may become difficult.

  The sulfur-containing anionic surfactant accounts for 0.2 to 80.0% by weight, preferably 1.0 to 60.0% by weight, based on the nonvolatile content of the decomposing agent of the cationic asphalt emulsion of the present invention. More preferably, 3.0 to 50.0% by weight is further preferable, and 5.0 to 40.0% by weight is particularly preferable. If it is less than 0.2% by weight, the immediate degradability may be poor. If it exceeds 80.0% by weight, the decomposition may not proceed to the lower non-contact layer.

  The pH of the decomposing agent for the cationic asphalt emulsion of the present invention is preferably 5.0 to 8.0, more preferably 5.5 to 7.5. If it is less than 5.0 or more than 8.0, the environment around the construction site may be adversely affected, and the safety of the worker may not be maintained.

  When the cationic asphalt emulsion decomposing agent of the present invention is used in the cationic asphalt emulsion "PK-4" defined in JIS-K2208, the effect of the present application is exhibited without being affected by the type of emulsifier and other components. Therefore, it is preferable.

  The decomposing agent for the cationic asphalt emulsion of the present invention may use a water-soluble solvent, an emulsifying / solubilizing agent, an antifoaming agent, etc. as other components to the extent that the effect thereof is not impaired.

  The water-soluble solvent is not particularly limited, but for example, methanol, ethanol, propanol, butanol, ethylene glycol, diethylene glycol, propylene glycol, 2-ethoxyethanol, 2- (2-ethoxyethoxy) ethanol, 2-butoxyethanol. , 2- (2-butoxyethoxy) ethanol, 3-methoxy-3-methyl-1-butanol, phenoxyethanol, and the like, and one kind or two or more kinds may be used in combination.

  The emulsifying / solubilizing agent is not particularly limited, but for example, an anionic surfactant other than the sulfur-containing anionic surfactant of the present invention, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant. Surfactants and the like can be mentioned, and one kind or two or more kinds may be used in combination.

  The defoaming agent is not particularly limited, and examples thereof include an ester defoaming agent, a polyether defoaming agent, a mineral oil defoaming agent, a silicone defoaming agent, and a powder defoaming agent. You may use together 1 type (s) or 2 or more types.

  The weight ratio of the other components in the decomposer of the cationic asphalt emulsion of the present invention is not particularly limited, but preferably 0.001 to 50% by weight, more preferably 0.1% by weight of the decomposer of the cationic asphalt emulsion. The amount is 01 to 30% by weight, more preferably 0.01 to 20% by weight, and particularly preferably 0.01 to 10% by weight. If the weight ratio of the other components is less than 0.001% by weight of the decomposer of the cationic asphalt emulsion, the quality of the decomposer of the cationic asphalt emulsion may deteriorate. On the other hand, if the weight ratio of the other components exceeds 50% by weight, the effect of the present application may not be sufficient.

[Method for producing decomposing agent for cationic asphalt emulsion]
The method for producing the decomposing agent of the present invention is not particularly limited as long as there is no undissolved or undispersed component remaining and the component is uniformly dissolved and dispersed, and examples thereof include the following methods.
(1) A method in which a sulfur-containing anionic surfactant, an inorganic sulfate and / or a condensed phosphate is added little by little to water and / or a solvent with stirring and mixed (2) an inorganic sulfate and / or a condensation A method in which a phosphate salt is dissolved in water and / or a solvent with stirring, and then a sulfur-containing anionic surfactant is added little by little with sufficient stirring and mixed (3). / Or a solution (A) dissolved in a solvent at a high concentration and a solution (B) in which an inorganic sulfate and / or a condensed phosphate is dissolved at a high concentration in water are separately prepared, and (A) is sufficiently stirred. While adding (B) little by little, mixing

[Method of spraying decomposer of asphalt emulsion]
The method of spraying the decomposer of the asphalt emulsion of the present invention is a method of contacting the above-mentioned cationic asphalt emulsion with the decomposer of the present invention.
The decomposer for the asphalt emulsion may be sprayed at the same time as the asphalt emulsion, or after the asphalt emulsion has been sprayed, the decomposer may be sprayed on it.
The asphalt emulsion is sprayed on the roadbed, the base layer, and the surface layer, and is also used for spraying and waterproofing of slopes and wall surfaces.However, since the decomposing agent of the asphalt emulsion of the present invention is excellent in immediate decomposability, these It can also be used for purposes.
When spraying, it is preferable to spray in an atomized state in order to make it uniform without spotting. For example, for small-scale paving, use an engine sprayer, gear sprayer, air sprayer, hand sprayer, airless pump sprayer, or the like. Alternatively, for large-scale paving, a device for spraying asphalt emulsion such as an asphalt sprayer, an asphalt distributor, an asphalt finisher with an emulsion spraying function may be used.
The amount of the decomposing agent applied is preferably 10 parts or more per 100 parts of the emulsion. If the amount is less than 10 parts, the degrading agent may not spread throughout the asphalt emulsion, resulting in poor immediate degradability.

[Production of decomposing agent]
Decomposing agents for the cationic asphalt emulsions of Examples 1 to 20 and Comparative Examples 1 to 12 were produced by the method (3) so that the mass ratios shown in Tables 1 to 3 were obtained.
Tables 1 to 3 show the results of measuring the specific gravity and viscosity of the decomposing agents of the cationic asphalt emulsions of Examples 1 to 20 and Comparative Examples 1 to 12 as follows.
The degradability test of the asphalt emulsion was conducted as follows. The test results are shown in Table 4.

〔specific gravity〕
The specific gravity of the decomposing agent of the cationic asphalt emulsion at a temperature of 20 ° C. was measured according to the method described in JIS-Z8804-9.
Density / specific gravity meter: DA-200 manufactured by Kyoto Electronics Manufacturing

〔viscosity〕
A Brookfield viscometer was used to measure the viscosity of the decomposing agent of the cationic asphalt emulsion at a temperature of 20 ° C.

[Degradability test of asphalt emulsion]
The cationic asphalt emulsion PK-4 was coated on the asphalt in two levels of emulsion amount (0.3 L / m ² 1.2 L / m ² ).
20% by weight of the amount of the asphalt emulsion was decomposed by spraying from above.
Immediately after 1 minute, 5 minutes, 10 minutes, and 15 minutes, the state of the emulsion was visually observed.
○ The decomposed water that is decomposed and separated into the lower layer is transparent. △ ^{1 The} surface is decomposed and forms a film, but the lower layer is not decomposed. △ ^{2 The} lower layer is decomposed but does not form a film and aggregates do not settle × 15 The test was accepted if the lower layer was decomposed within a minute and the asphalt formed a film, and the case where the asphalt emulsion did not decompose and remained even after 15 minutes or the separated asphalt did not form a film was regarded as a failure.

As can be seen from Table 4, in Examples 1 to 20, the sulfur-containing anionic surfactant and the inorganic sulfate and / or condensed phosphate were contained, and the specific gravity at 20 ° C. was 1.03 to 2.00. As a result, the asphalt emulsion has excellent immediate decomposability, and the decomposition is progressing not only to the surface layer part where the disintegrant and the asphalt emulsion were in contact at the time of spraying, but also to the non-contact lower layer part. ing.
On the other hand, when the sulfur-containing anionic surfactant is contained but the inorganic sulfate and / or the condensed phosphate is not contained (Comparative Examples 1 and 3 to 5), the inorganic sulfate is contained but the sulfur-containing anionic surfactant is contained. When no agent is included (Comparative Examples 2 and 11), when neither a phosphate salt nor a condensed phosphate salt (Comparative Example 6), and even when an anionic surfactant is not a sulfur-containing type (Comparative Examples 7 to 10) When the sulfur-containing anionic surfactant is not included and the inorganic sulfate and / or the condensed phosphate is not included (Comparative Example 12), the problem of the present application cannot be solved.

Claims (9)

And a sulfur-containing-type anionic surfactant and an inorganic acid salt and / or condensed phosphate salt, a specific gravity of 1.03 to 1.15 at 20 ° C., a viscosity at 20 ° C. is 0.1 mPa · s or more 121 Decomposing agent for cationic asphalt emulsion having mPa · s or less.   The decomposing agent according to claim 1, which has a specific gravity of 1.04 to 1.15 at 20 ° C and a viscosity of 11.1 to 121 mPa · s at 20 ° C.   The decomposing agent according to claim 1 or 2, wherein the sulfur-containing anionic surfactant contains at least one selected from an alkylsulfonic acid, an alkylsulfonic acid salt, an alkylbenzenesulfonic acid, and an alkylbenzenesulfonic acid salt.   The sulfur-containing anionic surfactant is at least one selected from dialkylsulfosuccinic acid, dialkylsulfosuccinate, sulfates of fats and oils, sulfates of fats and oils, sulfates of hardened fats and oils and sulfates of hardened fats and oils. The decomposing agent according to claim 1, further comprising:   The decomposing agent according to claim 1, wherein the inorganic sulfate contains at least one selected from ammonium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate, calcium sulfate and iron sulfate.   The decomposing agent according to claim 1, wherein the condensed phosphate contains at least one selected from pyrophosphate and tripolyphosphate.   The weight ratio of the sulfur-containing anionic surfactant is 0.1 to 30.0 parts by weight, and the weight ratio of the inorganic sulfate and / or the condensed phosphate is 0.1 to 100 parts by weight of the decomposer. The decomposing agent according to any one of claims 1 to 6, which is 50.0 parts by weight.   The decomposing agent according to any one of claims 1 to 7, wherein the cationic asphalt emulsion is "PK-4" defined in Japanese Industrial Standard JIS K2208.   A method for spraying an asphalt emulsion, which comprises contacting the degrading agent according to any one of claims 1 to 8 with a cationic asphalt emulsion.