Asphalt tack inhibitor and use thereof

Abstract

To provide an asphalt tack inhibitor that can effectively reduce asphalt adhesion with a small amount even in summer when the road surface temperature is high, without affecting the performance of asphalt itself.SOLUTION: An asphalt tack inhibitor includes at least one selected type of anionic surfactant (A), cationic surfactant (B) or glycerin fatty acid ester (C), of which the cationic surfactant (B) has an alkyl group with a carbon number of 12-22. It is preferable that the selected one type of anionic surfactant (A), cationic surfactant (B) or glycerin fatty acid ester (C) is solid at 60°C.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an anti-tack agent for asphalt 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.

[0003] As one method for improving the workability during handling at room temperature, the use of asphalt in a form emulsified in water using an emulsifier is known, and such emulsion is called asphalt emulsion. The main uses of asphalt emulsion in road pavement are the prime coat used for surface finishing of the roadbed and the tack coat used as an interface between the base course and the newly paved asphalt layer. When using asphalt emulsion for these purposes, in order to bring out the inherent performance of the asphalt, it is necessary to remove the moisture after spraying the emulsion and form an asphalt film. However, after the moisture is removed, there is a problem that the tack of the asphalt causes the asphalt film to adhere to the tires of construction vehicles and peel off. This problem occurs particularly frequently in the summer when road surface temperatures are high and the asphalt softens. Not only does the coating peel off, meaning that the asphalt coating's adhesive and waterproofing properties are not fully achieved, but construction vehicles with asphalt stuck to their tires can also cause damage to nearby roads.

[0004] In order to suppress tack, there is a tire adhesion suppression asphalt emulsion (PKM-T) that uses modified asphalt with a higher softening point by blending resin and rubber components into the asphalt. Moreover, in Patent Document 1, an attempt is made to prevent tackiness by using an emulsion in which colloidal silica is blended with an asphalt emulsion. However, in either case, unless a large amount of resin component or colloidal silica is blended, sufficient tack prevention effect cannot be obtained, resulting in an adverse effect on the performance of the asphalt itself. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2004-091761 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide an asphalt tack inhibitor that can effectively reduce the stickiness of asphalt with a small amount even in summer when road surface temperatures are high, without affecting the performance of the asphalt itself. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by an asphalt tack prevention agent containing a specific compound. That is, the asphalt anti-tack agent of the present invention contains at least one selected from an anionic surfactant (A), a cationic surfactant (B) and a glycerin fatty acid ester (C), and the cationic surfactant (B) has an alkyl group having 12 to 22 carbon atoms.

[0008] In the asphalt tack prevention agent of the present invention, at least one selected from the anionic surfactant (A), the cationic surfactant (B), and the glycerin fatty acid ester (C) is preferably solid at 60°C. The anionic surfactant (A) preferably contains a salt of a higher fatty acid having 6 to 22 carbon atoms. The cationic surfactant (B) is preferably a compound having an alkyl group having 16 or more carbon atoms. It is preferable that the composition further contains a compound (D) having a specific gravity at 20°C of 1.03 to 3.0. It is preferable that the tack inhibitor essentially contains the anionic surfactant (A), and that the proportion of the anionic surfactant (A) in the non-volatile content of the tack inhibitor is 30 to 99.9% by weight, and that the proportion of the compound (D) is 0.1 to 70% by weight.

[0009] The method for spraying an asphalt tack inhibitor of the present invention is a method for spraying an asphalt tack inhibitor, which comprises contacting an asphalt emulsion with the asphalt tack inhibitor. Effect of the Invention

[0010] The asphalt anti-tack agent of the present invention can effectively reduce the adhesion of asphalt in small amounts even in summer when road surface temperatures are high. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The asphalt tack inhibitor of the present invention contains at least one selected from an anionic surfactant (A), a cationic surfactant (B) and a glycerin fatty acid ester (C), and the cationic surfactant (B) has an alkyl group having 12 to 22 carbon atoms. The details are explained below.

[0012] [Anionic surfactant (A)] The anionic surfactant (A) has an affinity for both water and asphalt, and migrates to the interface between the water and asphalt, so after the asphalt emulsion is sprayed, it can reduce the adhesion of the asphalt by efficiently and evenly covering the surface of the asphalt that has formed a film. If the anionic surfactant (A) is solid at 60°C, it will lose fluidity after drying and will be difficult to peel off from the asphalt surface, resulting in a greater effect.

[0013] The anionic surfactant (A) is not particularly limited, but examples thereof include sulfonic acid type anionic surfactants, sulfate ester type anionic surfactants, phosphate ester type anionic surfactants, carboxylate type anionic surfactants, etc. Among these, at least one selected from sulfonic acid type anionic surfactants, phosphate ester type anionic surfactants, and carboxylate type anionic surfactants is preferred from the viewpoints that the anti-tack agent component adheres uniformly and without spots to the asphalt surface and that it can also function as a decomposer for the cationic asphalt emulsion.

[0014] Examples of the sulfonic acid type anionic surfactant include alkyl or alkenyl sulfonates, alkylbenzene sulfonates, naphthalene sulfonates, alkylnaphthalene sulfonates, salts of naphthalene sulfonate-formaldehyde condensates, melamine sulfonates, alkyl melamine sulfonates, salts of melamine sulfonate-formaldehyde condensates, salts of alkyl melamine sulfonate-formaldehyde condensates, alkyl sulfosuccinates, fatty acid amide sulfonates, acyl isethionates, and N-acyl-N-methyl taurate salts. Examples of the sulfate ester type anionic surfactant include alkyl sulfates, polyoxyalkylene alkyl ether sulfates, alkyl phenyl sulfates, polyoxyalkylene alkyl phenyl ether sulfates, salts of sulfates of oils and fats, and salts of sulfates of hardened oils and fats.

[0015] Examples of the phosphate ester type anionic surfactant include alkyl phosphates and polyoxyalkylene alkyl ether phosphates. Examples of the carboxylic acid type anionic surfactant include higher fatty acid salts, polyoxyalkylene alkyl ether carboxylates, and N-acylamino acid salts.

[0016] From the viewpoint of achieving the effects of the present invention, the higher fatty acid salt is preferably a compound represented by the following chemical formula (1). (R 1 COO)x 1 M 1 (1) In the formula, R 1 is an alkyl or alkenyl group having 5 to 21 carbon atoms, M 1 is at least one element selected from the group consisting of Group 1 elements, Group 2 elements, Group 12 elements, and Group 13 elements of the periodic table; 1 is M 1 Indicates the valence of. R 1 is preferably 7 to 17, more preferably 9 to 17, and particularly preferably 11 to 17. Said M 1 is preferably sodium or potassium.

[0017] From the viewpoint of achieving the effects of the present invention, the phosphate ester-based anionic surfactant is preferably a compound represented by the following chemical formula (2) and / or the following chemical formula (3). [R 2 O-(AO)n] 2 -P(=O)(OM 2 ) (2) In the formula, R 2 is an alkyl or alkenyl group having 6 to 22 carbon atoms, AO is an oxyalkylene group having 2 to 4 carbon atoms, n is an integer of 0 to 10, M 2 is at least one element selected from the group consisting of Group 1 elements, Group 2 elements, Group 12 elements, and Group 13 elements of the periodic table. [R 3 O-(AO)n]-P(=O)(OM 3 ) 2 (3) In the formula, R 3 is an alkyl or alkenyl group having 6 to 22 carbon atoms, AO is an oxyalkylene group having 2 to 4 carbon atoms, n is an integer of 0 to 10, M 3 is at least one element selected from the group consisting of Group 1 elements, Group 2 elements, Group 12 elements, and Group 13 elements of the periodic table. R 2 , R 3 is preferably 8 to 18, more preferably 10 to 18, and particularly preferably 12 to 18. Said M 2 , M 3 is preferably sodium or potassium.

[0018] Specific examples of the anionic surfactant (A) include sodium alkane sulfonate, sodium alkylbenzene sulfonate, sodium alkyl sulfate, sodium dioctyl sulfosuccinate, disodium sulfosuccinate alkylamide, sodium salt of naphthalenesulfonate-formaldehyde condensate, potassium lauryl ether phosphate, potassium oleyl ether phosphate, potassium stearyl ether phosphate, sodium polyoxyethylene lauryl ether phosphate, sodium polyoxyethylene stearyl ether phosphate, potassium caproate, potassium caprylate, potassium caprate, sodium laurate, potassium coconut fatty acid, potassium oleate, potassium tallow fatty acid, sodium stearate, sodium behenate, calcium laurate, calcium oleate, magnesium stearate, calcium stearate, zinc stearate, and the like.

[0019] Specific examples of the cationic surfactant (B) include lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, and behenyl trimethyl ammonium chloride.

[0020] Specific examples of the glycerol fatty acid ester (C) include glycerol monolaurate, glycerol monostearate, glycerol distearate, glycerol tristearate, glycerol tripalmitate, castor oil, rapeseed oil, soybean oil, sunflower oil, rice oil, beef tallow, hydrogenated castor oil, hydrogenated rapeseed oil, hydrogenated soybean oil, hydrogenated sunflower oil, hydrogenated rice oil, and hydrogenated beef tallow oil.

[0021] [Compound (D)] From the viewpoint of achieving the effects of the present invention, it is preferable that the asphalt anti-tack agent of the present invention further contains a compound (D) having a specific gravity at 20° C. of 1.03 to 3.0. From the viewpoint of achieving the effects of the present invention, the specific gravity of the compound (D) at 20° C. is more preferably from 1.04 to 2.7, further preferably from 1.05 to 2.3, and further preferably from 1.06 to 1.9.

[0022] Examples of the compound (D) include inorganic sulfates, phosphates, condensed phosphates, hydrochlorides, carbonates, glycerin, diglycerin, sorbitol, ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, and dimethyl sulfoxide. Among these, sulfates, hydrochlorides, glycerin, and polyethylene glycol are preferred in view of availability, safety, and environmental impact.

[0023] Examples of 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, and aluminum potassium sulfate. Among these, sodium sulfate, potassium sulfate, and ammonium sulfate are preferred in view of availability, safety, and environmental impact.

[0024] Examples of hydrochlorides include sodium chloride, potassium chloride, magnesium chloride, calcium chloride, aluminum chloride, and iron chloride.

[0025] The asphalt anti-tack agent of the present invention is preferable because, when it contains the compound (D), it promotes natural mixing with the asphalt emulsion, making it difficult for the anti-tack agent components on the surface to peel off after drying. It can also be used as a decomposer for cationic asphalt emulsion, and is preferable because it exerts the effect of shortening the construction time.

[0026] The asphalt tack prevention agent of the present invention may contain other ingredients such as solvents, emulsifiers / solubilizers, demulsifiers, and antifoaming agents to the extent that the effect of the agent is not impaired.

[0027] [Anti-tack agent for asphalt] The pH of an apparent 1% aqueous solution of the asphalt tack inhibitor of the present invention is preferably 4.0 to 12.0, more preferably 5.0 to 11.0, from the viewpoint of exerting the effects of the present invention. If it is less than 4.0, the workability during spraying may deteriorate. If it exceeds 12.0, the environment around the construction site may be adversely affected, and the safety of workers may not be ensured.

[0028] The viscosity of the asphalt anti-tack agent of the present invention at 20° C. is preferably 500 mPa·s or less, more preferably 400 mPa·s or less, even more preferably 300 mPa·s or less, and particularly preferably 200 mPa·s or less. If it exceeds 500 mPa·s, uneven application is likely to occur and the anti-tack effect may not be obtained. The preferred lower limit is 0.1 mPa·s. If the viscosity is less than 0.1 mPa·s, uneven application is likely to occur and the tack prevention effect may not be obtained.

[0029] From the viewpoint of exerting the effects of the present invention, the weight proportion of the anionic surfactant (A) in the non-volatile content of the asphalt tack prevention agent of the present invention is preferably 30 to 100% by weight, more preferably 40 to 100% by weight, even more preferably 50 to 100% by weight, and particularly preferably 60 to 100% by weight. From the viewpoint of exerting the effects of the present invention, the weight proportion of the cationic surfactant (B) in the non-volatile content of the asphalt anti-tack agent of the present invention is preferably 30 to 100% by weight, more preferably 40 to 100% by weight, even more preferably 50 to 100% by weight, and particularly preferably 60 to 100% by weight. From the viewpoint of exerting the effects of the present invention, the weight proportion of the glycerol fatty acid ester (C) in the non-volatile content of the asphalt tack prevention agent of the present invention is preferably 5 to 100% by weight, more preferably 10 to 80% by weight, even more preferably 10 to 60% by weight, and particularly preferably 10 to 50% by weight.

[0030] When the asphalt tack prevention agent of the present invention contains compound (D), the weight proportion of compound (D) in the non-volatile content of the asphalt tack prevention agent of the present invention is preferably 0.1 to 70% by weight, more preferably 0.5 to 50% by weight, even more preferably 1 to 40% by weight, and particularly preferably 2 to 30% by weight, from the viewpoint of exerting the effects of the present application. When the asphalt tack prevention agent of the present invention essentially contains the anionic surfactant (A) and also contains the compound (D), the weight proportion of the anionic surfactant (A) in the non-volatile content of the asphalt tack prevention agent of the present invention is preferably 30 to 99.9 wt%, more preferably 40 to 99 wt%, even more preferably 50 to 98 wt%, and particularly preferably 60 to 97 wt%, from the viewpoint of exerting the effects of the present application.

[0031] When the asphalt tack inhibitor of the present invention essentially contains the anionic surfactant (A) and also contains the compound (D), the weight ratio of the anionic surfactant (A) to the compound (D) in the non-volatile content of the asphalt tack inhibitor of the present invention is preferably (A) / (D)=0.01 to 600, more preferably 0.1 to 400, and even more preferably 0.5 to 200.

[0032] [Method for producing asphalt tack inhibitor] The method for producing the tack inhibitor of the present invention is not particularly limited as long as no undissolved or undispersed components remain and the agent is uniformly dissolved or dispersed. For example, the following methods can be mentioned. (1) A method in which an anionic surfactant (A), a cationic surfactant (B), a glycerol fatty acid ester (C), and a compound (D) (however, compound (D) is optional) are added little by little to water and mixed. (2) A method in which anionic surfactant (A), cationic surfactant (B), glycerol fatty acid ester (C), and compound (D) (compound (D) is optional) are dissolved in water and / or a solvent at high concentrations separately, and then the solutions are mixed while being thoroughly stirred.

[0033] [Method of spraying asphalt anti-tack agent] The method for spraying the asphalt tack inhibitor of the present invention is not particularly limited, but may be, for example, a spraying method in which the tack inhibitor of the present invention is brought into contact with an asphalt emulsion. The asphalt tack inhibitor may be sprayed simultaneously with the asphalt emulsion, or may be sprayed on top of the asphalt emulsion after it has been sprayed or dried. The anti-tack agent and asphalt emulsion may be applied warm. Asphalt emulsions are spread on roadbeds, base layers, and surface layers, and are also used for spray-on waterproofing of slopes and walls, etc., and the asphalt tack inhibitor of the present invention can be used for these applications as well.

[0034] When spraying, it is preferable to spray in a mist form to ensure uniformity without any spots. For example, 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, equipment for spraying asphalt emulsion, such as an asphalt sprayer, asphalt distributor, or asphalt finisher with emulsion spraying function, may be used. The amount of anti-tack agent to be sprayed is preferably 10 parts or more per 100 parts of emulsion. If the amount is less than 10 parts, the anti-tack agent will not spread over the entire asphalt surface, resulting in spots and poor anti-tack effect. EXAMPLES

[0035] The present invention will be described in detail with reference to the following examples and comparative examples, but the present invention is not limited to these examples. The physical properties of the asphalt tack inhibitor in the examples were evaluated by the following methods.

[0036] [Production of asphalt anti-tack agent]

[0037] The asphalt tack inhibitors of Examples 1 to 23 and Comparative Examples 1 to 7 were produced by the above method (2) so that the weight ratios of anionic surfactant (A) / cationic surfactant (B) / glycerol fatty acid ester (C) / compound (D) were as shown in Tables 1 to 4. The anti-stickiness test of the asphalt emulsion was carried out as follows. The test results are shown in Tables 1 to 4.

[0038] 〔specific gravity〕 The specific gravity of compound (D) at a temperature of 20° C. was measured in accordance with the methods described in JIS-Z8804-9 and JIS-Z8807-6. Density and specific gravity meter: Kyoto Electronics Manufacturing Co., Ltd. DA-200 Glycerin (specific gravity 1.26) Polyethylene glycol 1000 (specific gravity 1.12) Potassium sulfate (specific gravity 2.66) Magnesium sulfate heptahydrate (specific gravity 1.68)

[0039] [Asphalt stickiness prevention test] 0.4L / m of asphalt emulsion was applied to a slate board measuring 150mm in length, 150mm in width, and 1mm in thickness. 2 The asphalt emulsion was evenly coated, and then 10 wt% of the asphalt emulsion was sprayed on top of it with a spray bottle to prevent tackiness. The test specimen was then left to dry naturally for 24 hours. The test specimen was placed in a thermostatic chamber at 60°C and left to cure for 4 hours. The heated test specimen was touched with a finger to check whether the asphalt was sticky. A test with a rating of ○ or above was deemed to have passed. ◎ Not sticky at all ○ It feels slightly sticky on your fingers, but does not adhere. △ It sticks to your fingers and doesn't come off easily × Asphalt sticks to your fingers and peels off from the base

[0040] [Table 1]

[0041] [Table 2]

[0042] [Table 3]

[0043] [Table 4]

[0044] As can be seen from Tables 1 to 3, Examples 1 to 23 contain at least one selected from the group consisting of an anionic surfactant (A), a cationic surfactant (B), and a glycerin fatty acid ester (C), and the cationic surfactant (B) has an alkyl group having 12 to 22 carbon atoms, thereby solving the problem of preventing stickiness, which is the objective of the present application. On the other hand, as can be seen from Table 4, when at least one selected from the anionic surfactant (A), the cationic surfactant (B), and the glycerin fatty acid ester (C) is not included (Comparative Examples 1 to 7), the problem of the present application cannot be solved.

Claims

1. An asphalt tack inhibitor comprising at least one selected from an anionic surfactant (A), a cationic surfactant (B) and a glycerin fatty acid ester (C), wherein the cationic surfactant (B) has an alkyl group having 12 to 22 carbon atoms.

2. The asphalt tack inhibitor according to claim 1, wherein at least one selected from the anionic surfactant (A), the cationic surfactant (B), and the glycerin fatty acid ester (C) is solid at 60°C.

3. The asphalt tack inhibitor according to claim 1 or 2, wherein the anionic surfactant (A) comprises a salt of a higher fatty acid having 6 to 22 carbon atoms.

4. The asphalt tack inhibitor according to claim 1 or 2, wherein the cationic surfactant (B) is a compound having an alkyl group having 16 or more carbon atoms.

5. The asphalt tack inhibitor according to claim 1 or 2, further comprising a compound (D) having a specific gravity at 20°C of 1.03 to 3.

0.

6. The asphalt tack inhibitor according to claim 5, which essentially contains the anionic surfactant (A), and the proportion of the anionic surfactant (A) in the non-volatile content of the tack inhibitor is 30 to 99.9% by weight, and the proportion of the compound (D) is 0.1 to 70% by weight.

7. A method for spraying an asphalt tack prevention agent, comprising contacting an asphalt emulsion with the asphalt tack prevention agent according to claim 1 or 2.

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