JP4463769B2 - Asphalt emulsifying dispersant - Google Patents

Description

  The present invention relates to an asphalt emulsifying dispersant used for emulsifying asphalt, and an oil-in-water asphalt emulsion composition obtained by using the same.

  Asphalt is widely used for road paving, waterproofing / adhesive materials, railroad track laying and so on. However, since asphalt is very viscous at room temperature, workability is extremely poor. Therefore, in order to ensure the desired workability at room temperature, there is a technique of improving the fluidity and using it as a form of an oil-in-water emulsion composition using an appropriate emulsifier and water. As an emulsifier for an oil-in-water emulsion, an anionic emulsifier, a cationic emulsifier, a nonionic emulsifier, or an amphoteric emulsifier is known, and is properly used depending on each use.

  In addition, normal temperature mixture for paving (hereinafter referred to as “mixed material”) used for general roads, playgrounds, parking lots, etc. requires strength, durability, and wear resistance. Therefore, aggregates such as sand, gravel, cement, filler Etc. and a mixture of asphalt emulsions are used.

  However, asphalt emulsion compositions using conventional anionic emulsifiers, cationic emulsifiers, nonionic emulsifiers or amphoteric emulsifiers are not sufficiently mixed with aggregates such as sand, gravel, cement, filler, etc. In addition, the emulsion composition is separated or agglomerated, which makes it difficult to produce a composite material having excellent workability, and there are problems in strength and durability. In order to solve these problems, the combined use of an emulsifier and a foaming agent or a dispersant has been studied (Patent Document 1).

Patent Document 2 discloses a vinyl monomer having an oxyalkylene group having 2 to 3 carbon atoms as an asphalt emulsifying and dispersing agent for obtaining an asphalt emulsion composition excellent in cement mixing property, aggregate mixing property and durability. An asphalt emulsifying dispersant containing a water-soluble copolymer obtained by polymerizing a body (a) and a vinyl monomer (b) having a carboxyl group or the like is disclosed.
Japanese Patent Application Laid-Open No. 11-12016 JP 2002-20626 A

  However, it is difficult to say that these conventional asphalt emulsion dispersants can sufficiently improve the storage stability of the obtained asphalt emulsion. In addition, it is desirable that a mixture mixture composed of cement, asphalt emulsion, crushed stone, fine aggregate, etc. is excellent in mixing ability of cement and aggregate, but in this respect as well, conventional asphalt emulsion dispersants are further improved. Is desired.

  An object of the present invention is to provide an asphalt emulsifying and dispersing agent capable of obtaining an oil-in-water type asphalt emulsion composition excellent in cement mixing property, aggregate mixing property and storage stability of asphalt emulsion.

  The present invention relates to a monomer 1 represented by the following general formula (1), a monomer 2 represented by the following general formula (2), and a monomer 3 represented by the following general formula (3). An asphalt emulsifying dispersant containing the polymer A obtained by copolymerization of

[Wherein R ¹ and R ² are each a hydrogen atom or a methyl group, R ³ is a hydrogen atom or — (CH ₂ ) q (CO) pO (AO) rR ⁴ , and AO is an oxyalkylene having 2 to 4 carbon atoms. Group or oxystyrene group, p is a number of 0 or 1, q is a number of 0 to 2, p and q are not simultaneously 0, r is an average added mole number of AO, a number of 3 to 300, R ⁴ Represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. ]

[Wherein R ¹¹ is a hydrogen atom or a methyl group, R ¹² is an alkylene group having 2 to 12 carbon atoms, m1 is a number of 1 to 30, M ³ and M ⁴ are a hydrogen atom, an alkali metal or an alkaline earth metal, respectively. Represents. ]

[Wherein R ¹³ and R ¹⁵ are each a hydrogen atom or a methyl group, R ¹⁴ and R ¹⁶ are each an alkylene group having 2 to 12 carbon atoms, m2 and m3 are each a number of 1 to 30 and M ⁵ is Represents a hydrogen atom, an alkali metal or an alkaline earth metal. ]

  The present invention also provides an oil-in-water asphalt emulsion composition containing asphalt, the asphalt emulsifying dispersant of the present invention, and water.

  According to the present invention, there is provided an asphalt emulsifying dispersant capable of obtaining an oil-in-water type asphalt emulsion composition excellent in cement mixing property, aggregate mixing property and storage stability of asphalt emulsion.

<Polymer A>
The polymer A is represented by the monomer 1 represented by the above general formula (1), the monomer 2 represented by the above general formula (2), and the above general formula (3). This is a phosphate ester polymer obtained by copolymerizing the monomer 3.

[Monomer 1]
In monomer 1, R ¹ and R ² in general formula (1) are each a hydrogen atom or a methyl group. R ³ is a hydrogen atom or — (CH ₂ ) _q (CO) _p O (AO) _r R ⁴ , preferably a hydrogen atom. R ⁴ is a hydrogen atom or an alkyl group having 1 to 18 carbon atoms, preferably 1 to 12, more preferably 1 to 4, and further preferably 1 or 2, and particularly preferably a methyl group. When p is 0, AO forms an ether bond with (CH ₂ ) _q, and when p is 1, it forms an ester bond. q is 0 to 2, preferably 0 or 1, and more preferably 0. p and q are not 0 at the same time. AO is an oxyalkylene group having 2 to 4 carbon atoms or an oxystyrene group, and AO is preferably an oxyalkylene group having 2 to 4 carbon atoms, more preferably an ethyleneoxy group (hereinafter referred to as EO group), and an EO group. Is 70 mol% or more, more preferably 80 mol% or more, and further preferably 90 mol% or more, and in particular, all AO are preferably EO groups. r is the average number of moles of AO added, and is a number of 3 to 300, preferably 4 to 120, more preferably 4 to 80, and still more preferably 4 to 50, from the viewpoint of storage stability of the asphalt emulsion. In particular, this is preferably 4 to 30. Moreover, AO is different in an average of r repeating units, and random addition, block addition, or a mixture thereof may be included. For example, AO can contain a propyleneoxy group etc. besides EO group.

  Monomer 1 includes a half-terminated alkyl-capped polyalkylene glycol such as methoxypolyethylene glycol, methoxypolypropylene glycol, methoxypolybutylene glycol, methoxypolystyrene glycol, ethoxypolyethylenepolypropyleneglycol, (meth) acrylic acid, maleic acid (half ) Esterified products, etherified products with (meth) allyl alcohol, and (meth) acrylic acid, maleic acid, and (meth) allyl alcohol adducts having 2 to 4 carbon atoms are preferably used. In addition, (meth) acrylic acid means acrylic acid and / or methacrylic acid, and (meth) allyl means allyl and / or methallyl (the same applies hereinafter).

  More preferred is an esterified product of alkoxy, particularly methoxypolyethylene glycol and (meth) acrylic acid. Specific examples include ω-methoxypolyoxyalkylene methacrylate and ω-methoxypolyoxyalkylene acrylate, and ω-methoxypolyoxyalkylene methacrylate is more preferable.

  Monomer 1 used for production of polymer A can be obtained, for example, by esterification of alkoxypolyalkylene glycol and (meth) acrylic acid. The esterified product is preferably 5% by weight or less, preferably 3% by weight or less with respect to the monomer 1 in terms of acid type in terms of the unreacted (meth) acrylic acid from the viewpoint of cement mixing property and aggregate mixing property. More preferably, it is 1.5% by weight or less, more preferably 1% by weight or less. Examples of a method for reducing the amount of (meth) acrylic acid remaining during the production of the monomer 1 include topping, steaming, and solvent extraction.

[Monomer 2]
In the monomer (2), R ¹¹ is a hydrogen atom or a methyl group, and R ¹² is an alkylene group having 2 to 12 carbon atoms. m1 is a number from 1 to 30, and M ³ and M ⁴ are each a hydrogen atom, an alkali metal, or an alkaline earth metal. 1-20 are preferable, as for m1 in General formula (2), 1-10 are more preferable, and 1-5 are especially preferable.

  Specific examples include phosphoric acid monoesters of organic hydroxy compounds. Specific examples include polyalkylene glycol mono (meth) acrylate acid phosphates. For example, phosphoric acid mono-[(2-hydroxyethyl) methacrylic acid] ester, phosphoric acid mono-[(2-hydroxyethyl) acrylic acid ester] and the like can be mentioned. Among these, phosphoric acid mono-[(2-hydroxyethyl) methacrylic acid] ester is preferable from the viewpoint of ease of production and product quality stability. Further, alkali metal salts, alkaline earth metal salts, ammonium salts, alkylammonium salts and the like of these compounds may be used.

[Monomer 3]
In the monomer 3, in the general formula (3), R ¹³ and R ¹⁵ are each a hydrogen atom or a methyl group, and R ¹⁴ and R ¹⁶ are each an alkylene group having 2 to 12 carbon atoms. m2, m3 is a number of each 1 to 30, M ⁵ represents a hydrogen atom, an alkali metal or alkaline earth metal. M2 and m3 in the general formula (3) are each preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 5.

  Specific examples include phosphoric acid diesters of organic hydroxy compounds. Specific examples include polyalkylene glycol di (meth) acrylate acid phosphoric acid diester. Examples include phosphoric acid di-[(2-hydroxyethyl) methacrylic acid] ester, phosphoric acid di-[(2-hydroxyethyl) acrylic acid] ester, and the like. Among these, di-[(2-hydroxyethyl) methacrylic acid] ester phosphate is preferable from the viewpoint of ease of production and quality stability of the product. Further, alkali metal salts, alkaline earth metal salts, ammonium salts, alkylammonium salts and the like of these compounds may be used.

  Monomers 2 and 3 can be used as a mixed monomer including monomer 2 and monomer 3. Further, as the monomer 2 and the monomer 3, a phosphate ester obtained by reacting the organic hydroxy compound represented by the general formula (4) with a phosphorylating agent may be used.

  The mixed monomer including the monomer 2 and the monomer 3 is obtained as a reaction product by reacting, for example, an organic hydroxy compound represented by the general formula (4) and a phosphorylating agent at a predetermined charge ratio. It can also be manufactured.

[Wherein, R ²⁰ represents a hydrogen atom or a methyl group, R ²¹ represents an alkylene group having 2 to 12 carbon atoms, and m4 represents a number of 1 to 30. ]

  1-20 are preferable, as for m4 in General formula (4), 1-10 are more preferable, and 1-5 are especially preferable.

  Examples of the phosphorylating agent include orthophosphoric acid, phosphorus pentoxide (anhydrous phosphoric acid), polyphosphoric acid, phosphorus oxychloride and the like, and orthophosphoric acid and phosphorus pentoxide are preferable. These may be used alone or in combination of two or more. The amount of the phosphorylating agent in the reaction of the organic hydroxy compound and the phosphorylating agent can be appropriately determined according to the target phosphate ester composition.

  Examples of mixed monomers including monomer 2 and monomer 3 include mono-[(2-hydroxyethyl) methacrylic acid] phosphate and di-[(2-hydroxyethyl) methacrylic acid] phosphate. When the mixture is produced, it can be synthesized by a known technique (for example, JP-A-57-180618).

  As the mixed monomer including the monomer 2 and the monomer 3, a commercial product including a monoester and a diester can be used. For example, Phosmer M, Phosmer PE, Phosmer P (Unichemical) , JAMP514, JAMP514P, JMP100 (all Johoku Chemical), light ester P-1M, light acrylate P-1A (all Kyoeisha Chemical), MR200 (Daihachi Chemical), Kayamar (Nippon Kayaku), Ethyleneglycol methacrylate phosphate (Aldrich) Reagent).

  It has been confirmed that the above-mentioned commercial products and reaction products contain compounds other than the monoester (monomer 2) and diester (monomer 3). These other compounds are considered to be a mixture of polymerizable and non-polymerizable compounds, but in the present invention, such a mixture (mixed monomer) can be used as it is.

  The polymer A according to the present invention is a phosphate ester polymer obtained by copolymerizing the monomer 1, the monomer 2, and the monomer 3. It is also preferable to use a mixed monomer containing monomer 2 and monomer 3.

  In the copolymerization of the monomers, the molar ratio between the monomer 1 and the monomers 2 and 3 is as follows: monomer 1 / (monomer 2 + monomer 3) = 5/95 to 95/5, Furthermore, 10/90 to 90/10 are preferable. The molar ratio of monomer 1, monomer 2 and monomer 3 is as follows: monomer 1 / monomer 2 / monomer 3 = 5 to 95/3 to 90/1 to 80, and further 5 -96 / 3-80 / 1-60 (however, the total is 100) is preferable. In addition, about the monomer 2 and the monomer 3, the molar ratio and mol% shall be calculated based on an acid type compound (hereinafter the same).

  Moreover, in manufacture of the polymer A, it is preferable that the ratio of the monomer 3 shall be 1-60 mol%, and also 1-30 mol% in all the monomers used for reaction.

  The molar ratio of monomer 2 to monomer 3 is preferably monomer 2 / monomer 3 = 99/1 to 4/96, more preferably 99/1 to 5/95.

  From the viewpoint of suppressing gelation, the monomer solution containing monomer 2 and / or monomer 3 is preferably used for the reaction at a pH of 7 or less.

Hereinafter, more preferable production conditions will be described from the viewpoints of gelation suppression, adjustment of suitable molecular weight, asphalt emulsification dispersibility, and cement dispersibility. From such a viewpoint, at the time of copolymerization, 4 mol% or more, further 6 mol% or more, particularly 8 mol% or more of the chain transfer agent is used with respect to the total number of moles of the monomers 1, 2 and 3. It is preferable. The upper limit of the amount of chain transfer agent used is preferably 100 mol% or less, more preferably 60 mol% or less, still more preferably 30 mol% or less, based on the total number of moles of monomers 1, 2 and 3. Most preferably, it can be 15 mol% or less. More specifically, (1) when r of monomer 1 is 3 to 30,
(1-1) When the total molar ratio of the monomers 1, 2 and 3 of the monomer 2 and the monomer 3 is 50 mol% or more, the chain transfer agent is the monomers 1, 2 and 3 It is preferable to use 6 to 100 mol%, particularly 8 to 60 mol%, based on the total of
(1-2) When the molar ratio in the sum of monomers 1, 2 and 3 of monomer 2 and monomer 3 is less than 50 mol%, the chain transfer agent is monomer 1, 2 and It is preferable to use 4 to 60 mol%, particularly 5 to 30 mol%, based on the total of 3.
(2) When r of monomer 1 used for polymer A is more than 30, the chain transfer agent is used in an amount of 6 to 50 mol%, particularly 8 to 40 mol%, based on monomers 1 to 3. Is preferred.

  The reaction rate of the monomers 2 and 3 is preferably 60% or more, more preferably 70% or more, more preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. It can be selected from the viewpoint. Here, the reaction rate of the monomers 2 and 3 is calculated by the following equation.

In addition, the ratio (mol%) of the ethylenically unsaturated bond of the monomer 2 and the monomer 3 in the phosphorus-containing compound in the reaction system at the start and end of the reaction is measured by the following ¹ H-NMR. It can be calculated based on the result.
[ ¹ H-NMR conditions]
The polymer A dissolved in water and dried under reduced pressure is dissolved in deuterated methanol at a concentration of 3 to 4% by weight, and ¹ H-NMR is measured. The residual ratio of ethylenically unsaturated bonds is measured by an integral value of 5.5 to 6.2 ppm. In addition, the measurement of ¹ H-NMR uses “Mercury 400 NMR” manufactured by Varian, the number of data points is 42052, the measurement range is 6410.3 Hz, the pulse width is 4.5 μs, the pulse waiting time is 10 S, and the measurement temperature is 25.0 ° C. Perform under conditions.

  In the production of the polymer A, in addition to the monomers 1, 2, and 3, other monomers that can be copolymerized can also be used. Examples of other copolymerizable monomers include allyl sulfonic acid, methallyl sulfonic acid, any of these alkali metal salts, alkaline earth metal salts, ammonium salts, and amine salts. In addition, acrylic monomers such as acrylic acid, methacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and the like, and any one or more of alkali metal salts, alkalis Anhydrous compounds such as earth metal salts, ammonium salts, amine salts, methyl esters, ethyl esters and maleic anhydride may also be used. Furthermore, (meth) acrylamide, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2- (meth) acrylamide-2-metasulfonic acid, 2- (meth) acrylamide-2-ethanesulfonic acid, Examples include 2- (meth) acrylamide-2-propanesulfonic acid, styrene, styrenesulfonic acid and the like. The total proportion of monomers 1, 2, and 3 in all monomers is preferably 30 to 100 mol%, more preferably 50 to 100 mol%, particularly preferably 75 to 100 mol%, and more than 95 mol% to 100 Mole%, more preferably 97-100 mol% is preferred.

  In the production of the polymer A, monomers are preferably copolymerized in the presence of a predetermined amount of chain transfer agent. Moreover, you may use the other monomer, polymerization initiator, etc. which can be copolymerized.

  The reaction temperature of the monomers 1, 2 and 3 is preferably 40 to 100 ° C., more preferably 60 to 90 ° C., and the reaction pressure is 101.3 to 111.5 kPa (1 to 1.1 atm) in gauge pressure. 3-106.4 kPa (1-1.05 atm) is preferred.

  The pH of the reaction system can be adjusted with an inorganic acid (phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid, etc.), NaOH, KOH, triethanolamine, or the like, if necessary.

  Here, the monomer solution containing the monomer 2 and / or the monomer 3 is preferably a water-containing system (that is, the solvent contains water) for pH measurement. May be measured by adding the required amount of water. From the viewpoint of uniformity of the monomer solution, prevention of gelation, and suppression of performance degradation, the pH is preferably 7 or less, more preferably 0.1 to 6, and further preferably 0.2 to 4.5. Monomer 1 is also preferably used as a monomer solution having a pH of 7 or less. This pH is at 20 ° C.

  In the present invention, the pH at 20 ° C. of the reaction solution collected during the reaction (from the start of the reaction to the end of the reaction) is defined as the pH during the reaction. It is preferable to start the reaction under conditions that clearly show that the pH during the reaction is 7 or less (monomer ratio, solvent, other components, etc.).

  When the reaction system is non-aqueous, it can be measured by adding an amount of water capable of measuring pH to the reaction system.

In the production method of the polymer A, the monomers 1, 2 and 3 are usually reacted under the consideration of other conditions if they are reacted under the conditions exemplified in the following (1) and (2). The pH inside is considered to be 7 or less.
(1) A monomer solution having a pH of 7 or less containing all of the monomers 1, 2 and 3 is used for the copolymerization reaction of the monomers 1, 2 and 3.
(2) The copolymerization reaction of the monomers 1, 2 and 3 is started at pH 7 or less. That is, the reaction is started after the reaction system containing the monomers 1, 2 and 3 is brought to pH 7 or lower.

[Chain transfer agent]
The chain transfer agent has a function of causing a chain transfer reaction in radical polymerization (a reaction in which a growing polymer radical reacts with another molecule to move a radical active site). From the viewpoint of asphalt emulsifying dispersibility and cement dispersibility among the substances to be added, it is preferable to use a chain transfer agent during the polymerization.

  Examples of chain transfer agents include thiol chain transfer agents and halogenated hydrocarbon chain transfer agents, and thiol chain transfer agents are preferred.

As the thiol chain transfer agent, those having a —SH group are preferable, and in particular, the general formula HS—R—Eg (wherein R represents a hydrocarbon-derived group having 1 to 4 carbon atoms, and E is − OH, —COOM, —COOR ′ or —SO ₃ M group, M represents a hydrogen atom, monovalent metal, divalent metal, ammonium group or organic amine group, and R ′ represents an alkyl having 1 to 10 carbon atoms. In which g represents an integer of 1 to 2, for example, mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, Examples include octyl thioglycolate, octyl 3-mercaptopropionate, and the like from the viewpoint of chain transfer effect in a copolymerization reaction including monomers 1 to 3. Mercaptoethanol are preferable, more preferably mercaptopropionic acid. These 1 type (s) or 2 or more types can be used.

  Examples of the halogenated hydrocarbon chain transfer agent include carbon tetrachloride and carbon tetrabromide.

  Examples of other chain transfer agents include α-methylstyrene dimer, terpinolene, α-terpinene, γ-terpinene, dipentene, 2-aminopropan-1-ol and the like. A chain transfer agent can use 1 type (s) or 2 or more types.

[Polymerization initiator]
In the production method of the polymer A, it is preferable to use a polymerization initiator, and in particular, the polymerization initiator is 5 mol% or more, further 7 to 50 mol% with respect to the total number of moles of the monomers 1, 2 and 3. In particular, it is preferable to use 10 to 30 mol%.

  Examples of aqueous polymerization initiators include ammonium persulfate salt or alkali metal salt, hydrogen peroxide, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis (2-methylpropionamide) dihydrate, etc. These water-soluble azo compounds can be used. In addition, an accelerator such as sodium bisulfite and an amine compound can be used in combination with the polymerization initiator.

[solvent]
The production of the polymer A can be carried out by a solution polymerization method, and the solvent used at that time contains water or water and methyl alcohol, ethyl alcohol, isopropyl alcohol acetone, methyl ethyl ketone or the like. Examples of the solvent include hydrous solvents. In view of handling and reaction equipment, water is preferred. In particular, when an aqueous solvent is used, the pH of the monomer solution containing the monomer 2 and / or the monomer 3 is preferably 7 or less, more preferably 0.1 to 6, particularly 0.2 to 4. A copolymerization reaction is preferably used for the reaction in terms of uniformity of the monomer mixture (handleability), monomer reaction rate, and suppression of crosslinking by hydrolysis of the pyro compound of the phosphoric acid compound.

  An example of the manufacturing method of the polymer A is shown. A predetermined amount of water is charged into a reaction vessel, the atmosphere is replaced with an inert gas such as nitrogen, and the temperature is raised. Prepare monomer 1, monomer 2, monomer 3, chain transfer agent mixed and dissolved in water, and polymerization initiator dissolved in water, and take 0.5 to 5 hours. Drip into the reaction vessel. At that time, each monomer, chain transfer agent and polymerization initiator may be dropped separately, or a mixed solution of monomers can be charged in a reaction vessel in advance and only the polymerization initiator can be dropped. is there. That is, the chain transfer agent, the polymerization initiator, and other additives may be added as an additive solution separately from the monomer solution, or may be added to the monomer solution after being added. From the viewpoint of stability, it is preferable to supply the reaction system as an additive solution separately from the monomer solution. In any case, the pH of the solution containing the monomer 2 and / or the monomer 3 is preferably 7 or less. Further, the copolymerization reaction is preferably performed with an acid agent or the like while maintaining the pH at 7 or less, and preferably aging is performed for a predetermined time. The polymerization initiator may be added dropwise at the same time as the monomer, or may be added in portions, but it is preferable to add in portions in terms of reducing unreacted monomers. For example, in the total amount of the polymerization initiator to be finally used, 1/2 to 2/3 polymerization initiator is added simultaneously with the monomer, and the remainder is aged for 1 to 2 hours after the completion of the monomer dropping, It is preferable to add. If necessary, it is further neutralized with an alkali agent (such as sodium hydroxide) after completion of ripening to obtain the phosphate ester polymer according to the present invention. This production example is suitable as a method for producing the polymer A according to the present invention.

  The total amount of monomers 1, 2 and 3 in the reaction system and other copolymerizable monomers is preferably 5 to 80% by weight, more preferably 10 to 65% by weight, and particularly preferably 20 to 50% by weight. .

  The polymer A preferably has a weight average molecular weight (Mw) of 10,000 to 150,000. This polymer A has an Mw of 10,000 or more, preferably 12,000 or more, more preferably 13,000 or more, more preferably 14,000 or more, and particularly preferably from the viewpoint of emulsifying dispersibility of asphalt. From 15,000 or more, it is 150,000 or less, preferably 130,000 or less, more preferably 120 from the viewpoints of high molecular weight due to crosslinking, suppression of gelation and performance in terms of cement mixing properties and aggregate mixing properties. 1,000 or less, more preferably 110,000 or less, particularly preferably 100,000 or less, and from the viewpoints of both, preferably 12,000 to 130,000, more preferably 13,000 to 120,000, Preferably it is 14,000-110,000, Most preferably, it is 15,000-100,000. It is preferable to have Mw in this range and Mw / Mn is 1.0 to 2.6. Here, Mn is a number average molecular weight.

Mw and Mn of the polymer A are measured by gel permeation chromatography (GPC) method under the following conditions. In addition, Mw / Mn of the polymer A in this invention shall be computed based on the peak of this polymer.
[GPC conditions]
Column: G4000PWXL + G2500PWXL (Tosoh)
Eluent: 0.2M phosphate buffer / CH ₃ CN = 9/1
Flow rate: 1.0mL / min
Column temperature: 40 ° C
Detection: RI
Sample size: 0.2mg / mL
Reference material: Polyethylene glycol equivalent

  Polymer A satisfying Mw / Mn as described above has an appropriate branched structure by suppressing cross-linking by the monomer 3 which is a diester, and forms a structure in which adsorbing groups are densely present in the molecule. it is conceivable that. Mw / Mn can be controlled by adjusting the amount of the chain transfer agent, for example. When the amount of the chain transfer agent is increased, Mw / Mn tends to decrease.

  The Mw / Mn of the polymer A as described above is preferably 1.0 or more from the viewpoint of ensuring practical production ease, asphalt emulsification dispersibility and cement mixing properties, and achieves both dispersibility and viscosity reduction effect. In view of the above, 2.6 or less is preferable, more preferably 2.4 or less, more preferably 2.2 or less, still more preferably 2.0 or less, and particularly preferably 1.8 or less. From this viewpoint, it is preferably 1.0 to 2.4, more preferably 1.0 to 2.2, more preferably 1.0 to 2.0, and particularly preferably 1.0 to 1.8.

  Further, in the chart pattern showing the molecular weight distribution obtained by the GPC method under the above-mentioned conditions, the area where the molecular weight is 100,000 or more is 5% or less of the total area of the chart, and the dispersed cement particles are difficult to aggregate. And more preferable.

[Asphalt emulsifying dispersant]
The asphalt emulsifying dispersant of the present invention contains the polymer A.

  The content of the polymer A according to the present invention in the emulsifying dispersant is preferably 0.1 to 100% by weight, and the content of this copolymer in the asphalt emulsion composition varies depending on the purpose of use. Is 0.05 to 10% by weight, more preferably 0.1 to 5% by weight.

  Although the asphalt emulsion composition using the asphalt emulsifying dispersant of the present invention is not necessarily clear in terms of the cement mixing property, the aggregate mixing property, and the durability, the polymer A according to the present invention is made of cement or aggregate. Adsorbing on the surface exerts a protective colloidal function and suppresses the reaction of cement, the reaction of cement and asphalt emulsion, and the reaction of aggregate and asphalt emulsion, so that the mixing property is expected to be improved. In addition, since the mixability is good, it is considered that cement, aggregate, and asphalt emulsion are uniformly mixed, and the road is sufficiently solidified at the time of road construction, so that pavement with excellent durability is possible.

  The combined use of the polymer A used in the present invention with at least one selected from the group consisting of an anionic emulsifier, a cationic emulsifier, a nonionic emulsifier or an amphoteric emulsifier can further enhance the emulsifying performance of asphalt.

  Examples of the anionic emulsifier include fatty acids, alkyl sulfates, alkyl ether sulfates, alkylbenzene sulfonic acids, alkyl phosphoric acids, or salts thereof. Examples of the cationic emulsifier include mineral acids of amines such as alkylamines, alkylpolyamines, amidoamines, and alkylimidazolines, lower carboxylic acid salts, and quaternary ammonium salts. Examples of amphoteric emulsifiers include betaine acetate, amide betaine, sulfobetaine, imidazolium betaine, and amine oxide. Examples of nonionic emulsifiers include sorbitan esters, AO adducts of sorbitan esters, ethylene oxide adducts of long chain alcohols, ethylene oxide adducts of alkylphenols, alkyl glycosides, and the like.

  The combined ratio of the polymer A and the other emulsifier varies depending on the purpose of use, but is preferably a weight ratio of polymer A / emulsifier = 0.1 / 99.9 to 99.9 / 0.1, more preferably Is 0.5 / 99.5 to 50/50, more preferably 1/99 to 30/70.

  The asphalt emulsifying dispersant of the present invention is preferably mixed with water in advance when emulsifying asphalt and added to the asphalt. However, a part of the emulsifying dispersant of the present invention is mixed with the emulsion composition and the aggregate. It is also possible to add at the time of manufacturing the composite material.

  The asphalt emulsifying dispersant of the present invention can be used in combination with a water-soluble polymer for the purpose of improving the storage stability of the asphalt emulsion. Examples of the water-soluble polymer include polyvinyl alcohol, hydroxyethyl cellulose, carboxymethyl cellulose, methyl cellulose, cationized cellulose, and gums. Furthermore, phenolic compounds such as tannin and gallic acid can be added for the purpose of improving the adhesion between the aggregate after construction and asphalt.

  The addition amount of the asphalt emulsifying dispersant of the present invention is preferably 0.02 to 10% by weight, more preferably 0.05 to 5% by weight, based on the total weight of asphalt and water.

[Asphalt emulsion composition]

  The oil-in-water asphalt emulsion composition of the present invention contains asphalt, the asphalt emulsifying dispersant of the present invention and water.

  Examples of the asphalt used in the present invention include straight asphalt, cutback asphalt, blown asphalt, semi-blown asphalt, polymer-modified asphalt, natural bitumen, and regenerated asphalt.

  The content of asphalt and water in the oil-in-water asphalt emulsion composition is preferably 40 to 80% by weight from the viewpoint of storage stability of the emulsion and strength and durability of the road pavement, More preferably, it is 50 to 75% by weight, and the water content is preferably 20 to 60% by weight, and more preferably 25 to 50% by weight.

  The asphalt emulsion composition of the present invention can be produced by an emulsifier such as a colloid mill, a homogenizer, or a line mixer.

  The asphalt emulsion composition of the present invention may be used by mixing with cement, aggregate, other additives and the like. Examples of the cement include ordinary Portland cement, high belite cement, medium heat cement, early strength cement, ultra-fast strength cement, sulfuric acid-resistant cement, and the like. It may be added with calcium carbonate powder).

  In addition, in the present invention, if necessary, a foaming agent, a setting retarder, or other admixtures can be used.

  Examples of the foaming agent include powders of aluminum, zinc, magnesium, silicon alloy and the like, and aluminum powder is preferable.

  Examples of the setting retarder include citric acid, sodium citrate, and a C5 olefin / sodium maleate copolymer.

  The asphalt emulsion composition of the present invention can be used as a filling material under a concrete plate such as a semi-flexible pavement injection material or a sub-sealing, a support material for block pavement, and the like.

Below, the manufacture example of the polymer A used by the Example and the comparative example is shown.
<Production Example A1>
366 g of water was charged into a glass reaction vessel (four-necked flask) equipped with a stirrer, and was purged with nitrogen while stirring, and the temperature was raised to 80 ° C. in a nitrogen atmosphere. 450 g of ω-methoxypolyethyleneglycol monomethacrylate (average added mole number of ethylene oxide 23) (effective content 60.8%, moisture 35%), mono (2-hydroxyethyl) methacrylic acid ester and di-[( 2-hydroxyethyl) methacrylic acid] ester, a mixture of 71.6 g of phosphoric acid ester (A) and 4.5 g of 3-mercaptopropionic acid and ammonium persulfate. Two of 8.4 g dissolved in 48 g of water were added dropwise over 1.5 hours. After aging for 1 hour, 1.8 g of ammonium persulfate dissolved in 10 g of water was added dropwise over 30 minutes, and then aging was carried out at the same temperature (80 ° C.) for 1.5 hours. After completion of aging, the copolymer A-1 having a weight average molecular weight (Mw) of 35000 and a weight average molecular weight / number average molecular weight (Mw / Mn) of 1.29 was neutralized with 44.4 g of a 32% aqueous sodium hydroxide solution. Obtained. (Monomer polymerization pH: 1.0, reaction rate 100%)

The phosphoric acid ester (A) was prepared by charging 200 g of 2-hydroxyethyl methacrylate and 36.0 g of 85% phosphoric acid (H ₃ PO ₄ ) in a reaction vessel, and phosphorous pentoxide (phosphoric anhydride) (P ₂ O ₅ ) After gradually adding 89.1 g while cooling so that the temperature does not exceed 60 ° C., the reaction temperature is set to 80 ° C., the reaction is performed for 6 hours, and after cooling, phosphoric acid ester (A) is added. Obtained. This phosphate esterified product (A) was also used in some of the following production examples.

<Production Example A2>
371 g of water was charged into a glass reaction vessel with a stirrer (four-necked flask), purged with nitrogen while stirring, and heated to 80 ° C. in a nitrogen atmosphere. 500 g of ω-methoxypolyethylene glycol monomethacrylate (average added mole number of ethylene oxide 23) (effective content 60.8%, moisture 35%), mono (2-hydroxyethyl) methacrylic acid ester and di-[( 2-hydroxyethyl) methacrylic acid] ester, a mixture of 34.1 g of phosphoric acid ester (A) and 2.8 g of 3-mercaptopropionic acid and ammonium persulfate. Two of 7.2 g dissolved in 41 g of water were added dropwise over 1.5 hours. After aging for 1 hour, 1.6 g of ammonium persulfate dissolved in 9 g of water was added dropwise over 30 minutes, and then aging was carried out at the same temperature (80 ° C.) for 1.5 hours. After completion of aging, the mixture was neutralized with 21.2 g of a 32% aqueous sodium hydroxide solution to obtain a copolymer A-2 having a weight average molecular weight of 34000 and Mw / Mn of 1.28. (Monomer polymerization pH: 1.1, reaction rate 100%)

<Production Example A3>
A glass reaction vessel (four-necked flask) with a stirrer was charged with 381 g of water, purged with nitrogen while stirring, and heated to 80 ° C. in a nitrogen atmosphere. 520 g of ω-methoxypolyethylene glycol monomethacrylate (average added mole number of ethylene oxide 23) (effective content 60.8%, moisture 35%), mono (2-hydroxyethyl) methacrylate and di-[( 2-hydroxyethyl) methacrylic acid] ester, a mixture of 28.6 g of phosphoric acid ester (A) and 2.8 g of 3-mercaptopropionic acid and ammonium persulfate. Two of 7.2 g dissolved in 41 g of water were added dropwise over 1.5 hours. After aging for 1 hour, 1.6 g of ammonium persulfate dissolved in 9 g of water was added dropwise over 30 minutes, and then aging was carried out at the same temperature (80 ° C.) for 1.5 hours. After completion of aging, the mixture was neutralized with 17.7 g of a 32% aqueous sodium hydroxide solution to obtain a copolymer A-3 having a weight average molecular weight of 36000 and Mw / Mn of 1.27. (Monomer polymerization pH: 1.1, reaction rate 100%)

<Production Example A4>
A glass reaction vessel (four-necked flask) equipped with a stirrer was charged with 471 g of water, purged with nitrogen while stirring, and heated to 80 ° C. in a nitrogen atmosphere. 290 g of ω-methoxypolyethyleneglycol monomethacrylate (average addition mole number of ethylene oxide 9) (effective content 84.4%, moisture 10%), mono (2-hydroxyethyl) methacrylate and di-[( 2-hydroxyethyl) methacrylic acid] ester, a mixture of 93.8 g of phosphoric acid ester (A) and 11.3 g of 3-mercaptopropionic acid and ammonium persulfate. Two of the 8.2 g dissolved in 46 g of water were added dropwise over 1.5 hours. After aging for 1 hour, a solution prepared by dissolving 3.3 g of ammonium persulfate in 19 g of water was dropped over 30 minutes, and then aging was performed at the same temperature (80 ° C.) for 1.5 hours. After completion of aging, the mixture was neutralized with 58.2 g of a 32% aqueous sodium hydroxide solution to obtain a copolymer A-4 having a weight average molecular weight of 25000 and Mw / Mn of 1.21. (Monomer polymerization pH: 1.0, reaction rate 99%)

<Production Example A5>
489 g of water was charged into a glass reaction vessel (four-necked flask) equipped with a stirrer, purged with nitrogen while stirring, and heated to 80 ° C. in a nitrogen atmosphere. 290 g of ω-methoxypolyethyleneglycol monomethacrylate (average addition mole number of ethylene oxide 9) (effective content 84.4%, moisture 10%), mono (2-hydroxyethyl) methacrylate and di-[( 2-hydroxyethyl) methacrylic acid] ester, a mixture of 53.2 g of phosphoric acid ester (A) and 9.1 g of 3-mercaptopropionic acid and ammonium persulfate. Two of 7.8 g dissolved in 44 g of water were added dropwise over 1.5 hours. After aging for 1 hour, a solution prepared by dissolving 3.1 g of ammonium persulfate in 18 g of water was dropped over 30 minutes, and then aging was performed at the same temperature (80 ° C.) for 1.5 hours. After completion of aging, the mixture was neutralized with 33.0 g of a 32% aqueous sodium hydroxide solution to obtain a copolymer A-5 having a weight average molecular weight of 21000 and Mw / Mn of 1.18. (Monomer polymerization pH: 1.1, reaction rate 98%)

  Tables 1 to 3 show the compositions of the asphalt emulsifying dispersant of the present invention used in Examples and Comparative Examples.

  The molecular weight of the copolymer in the table is the weight average molecular weight determined from the molecular weight in terms of gel permeation chromatography method / sodium polystyrene sulfonate. In the table, EO represents ethylene oxide, and the next number in parentheses represents the average number of moles added. POE is an abbreviation for polyoxyethylene, and EOp is the average number of moles of ethylene oxide added. Mw is a weight average molecular weight.

(Production of asphalt emulsion composition)
Straight asphalt with a penetration of 80 to 100 was heated and melted at 145 ° C. A total of 5.0% by weight (2.0% by weight based on the asphalt emulsion composition) of the water-soluble copolymers and emulsifiers shown in Tables 1 to 3 is dissolved in warm water at 50 ° C. at a predetermined ratio. Prepared. 60 parts by weight of the molten asphalt and 40 parts by weight of the emulsifying dispersant were simultaneously passed through a colloid mill (5000 rpm) to obtain an asphalt emulsion composition. After the obtained asphalt emulsion composition was cooled to room temperature, the storage stability, cement mixing property, mixing state and residual stability of the asphalt emulsion were measured by the following methods. The results are shown in Table 4.

(Storage stability of asphalt emulsion composition)
Based on the JIS K 2280 “Storage Stability” test method, the asphalt emulsion storage stability of the asphalt emulsion composition after standing at 25 ° C. for 24 hours was measured. The lower the numerical value, the less the asphalt emulsion is separated.

(Cement mixing)
Measured according to the cement mixing test method, page 497, “Handbook of Pavement Test Methods” (December 20, 1993, 6th edition) edited by Japan Road Association. The smaller the measured value, the better the mixability between the cement and the asphalt emulsion composition.

(Residual stability)
A specimen was prepared by the Marshall stability test method on page 507 of “Handbook of Pavement Test Method”, and the ratio of water immersion strength to non-water immersion strength was defined as residual stability. The higher the residual stability, the better the durability. The curing conditions were as follows: after curing for 28 days in the atmosphere at 20 ° C., the specimen for water immersion strength measurement was cured for 7 days in 20 ° C. water, and the specimen for non-water immersion strength measurement was cured for 7 days in the air at 20 ° C.

(Mixed state)
The mixing state at the time of producing the room temperature asphalt mixture for pavement was evaluated as the mixing property of the aggregate. That is, 35 parts by weight of crushed stone No. 6, 42 parts by weight of fine sand, 6 parts by weight of screenings, 7 parts by weight of ordinary Portland cement, 10 parts by weight of asphalt emulsion composition, and in Comparative Example 11, a foaming agent (aluminum powder C-250, Nakajima Metal Foil Powder Industry Co., Ltd. (0.2 part by weight) was put into a mortar mixer and mixed for 2 minutes to produce an asphalt mixture. The mixing amount for one batch is 10 kg. The state of mixing of the mixture (surface diameter of about 30 cm) in the mixer immediately after kneading is visually observed, and the state of uniform mixing without separation of No. 6 crushed stone and other components is “good”. Three-stage evaluation was performed, assuming that the state in which 10 crushed stones were separated was “normal” and the state in which 11 or more crushed stones were separated was “bad”.

表４から明らかなように、本発明のアスファルト乳化分散剤は、乳剤組成物のセメント混合性を飛躍的に改良すると共に、骨材混合性をも改善しアスファルト合材の作業性を良好にする。また、乳剤組成物の貯蔵安定性も良好となる。さらに、本発明のアスファルト乳化分散剤で乳化したアスファルト乳剤組成物を用いた舗装用合材の残留安定度は十分に高く実用上問題ない強度を有しており、耐久性に優れる道路舗装体を得ることができる。

As is apparent from Table 4, the asphalt emulsifying dispersant of the present invention dramatically improves the cement mixing property of the emulsion composition and also improves the aggregate mixing property, thereby improving the workability of the asphalt mixture. . Also, the storage stability of the emulsion composition is improved. Furthermore, the residual stability of the pavement mixture using the asphalt emulsion composition emulsified with the asphalt emulsifying dispersant of the present invention has a sufficiently high residual strength that is not problematic in practice, and a road pavement having excellent durability. Obtainable.

Claims (5)

Monomer 1 represented by the following general formula (1), monomer 2 represented by the following general formula (2), and monomer 3 represented by the following general formula (3) are copolymerized An asphalt emulsifying dispersant containing the polymer A obtained as described above.

[Wherein R ¹ and R ² are each a hydrogen atom or a methyl group, R ³ is a hydrogen atom or — (CH ₂ ) q (CO) pO (AO) rR ⁴ , and AO is an oxyalkylene having 2 to 4 carbon atoms. Group or oxystyrene group, p is a number of 0 or 1, q is a number of 0 to 2, p and q are not simultaneously 0, r is an average added mole number of AO, a number of 3 to 300, R ⁴ Represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. ]

[Wherein R ¹¹ is a hydrogen atom or a methyl group, R ¹² is an alkylene group having 2 to 12 carbon atoms, m1 is a number of 1 to 30, M ³ and M ⁴ are a hydrogen atom, an alkali metal or an alkaline earth metal, respectively. Represents. ]

[Wherein R ¹³ and R ¹⁵ are each a hydrogen atom or a methyl group, R ¹⁴ and R ¹⁶ are each an alkylene group having 2 to 12 carbon atoms, m2 and m3 are each a number of 1 to 30 and M ⁵ is Represents a hydrogen atom, an alkali metal or an alkaline earth metal. ] The asphalt emulsifying dispersant according to claim 1, wherein the polymer A is obtained by copolymerizing the monomers 1 to 3 at a pH of 7 or less. The asphalt emulsifying dispersant according to claim 1 or 2, wherein the polymer A is obtained by copolymerizing monomers 1 to 3 in the presence of a chain transfer agent. The asphalt emulsifying dispersant according to any one of claims 1 to 3, further comprising at least one selected from the group consisting of an anionic emulsifier, a cationic emulsifier, a nonionic emulsifier, and an amphoteric emulsifier. An oil-in-water asphalt emulsion composition containing asphalt, the asphalt emulsifying dispersant according to any one of claims 1 to 4, and water.