TW201902855A - Dispersion retention agent for hydraulic composition - Google Patents

Abstract

The invention provides a dispersion retention agent for hydraulic composition, by which the hydraulic composition still retains fluidity, and less curing retardation, even after kneading for a long period of time. The dispersion retention agent for hydraulic composition of the present invention is a vinyl copolymer, which uses a specific monomer having a carboxyl group in the molecule, a specific monomer having a residue of poly-alkylene glycol in the molecule, and optionally other monomers which can be copolymerized with these monomers, for copolymerization.

Description

 Dispersion retention agent for hydraulic composition  

The present invention relates to a dispersion retaining agent for a hydraulic composition. Various dispersing agents are widely used in the preparation of hydraulic compositions such as mortars and concrete. However, generally, when a hydraulic composition is prepared using a dispersing agent, the loss of twist (the deterioration of fluidity with time) is large, and the workability and workability are lowered. The present invention relates to a dispersion-preserving agent for a hydraulic composition capable of sufficiently preventing loss of twist.

In the prior art, a dispersing agent for a hydraulic composition composed of a water-soluble ethylene-based copolymer is proposed (see, for example, Patent Documents 1 to 4). However, these conventional proposals have a problem that the loss of twist of the prepared hydraulic composition cannot be sufficiently prevented. Therefore, it has also been proposed to use an anti-caries loss agent in combination with a dispersant for a hydraulic composition (for example, refer to Patent Document 5). However, this conventional proposal still has a problem that the loss of twist of the prepared hydraulic composition cannot be sufficiently prevented.

[Patent Document 1] Japanese Patent Laid-Open Publication No. SHO 63-285140

[Patent Document 2] Japanese Patent Laid-Open No. 1-226757

[Patent Document 3] Japanese Patent Laid-Open No. Hei 10-67549

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2003-335562

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2003-34565

The problem to be solved by the present invention is to provide a dispersion-preserving agent for a hydraulic composition which can maintain the fluidity of the hydraulic composition after a long period of time from the kneading.

However, the inventors of the present invention have intensively studied to solve the above problems, and as a result, have found that a specific monomer having a carboxyl group in a molecule, a specific monomer having a polyalkylene glycol residue in a molecule, and, if necessary, The ethylene-based copolymer obtained by copolymerization of another monomer copolymerized in the form of a copolymer can be suitably used as a dispersion-preserving agent for a hydraulic composition.

In other words, the dispersion-retaining agent for a hydraulic composition of the present invention contains an ethylene-based copolymer obtained from the monomer A shown in the following Formula 1 and the monomer B shown in the following Chemical Formula 2. Further, the dispersion-retaining agent for a hydraulic composition of the present invention contains the monomer A represented by the following Chemical 1, the monomer B represented by the following Chemical Formula 2, and the other monomer copolymerizable with the monomers. The ethylene-based copolymer obtained in C.

[Chemical 1]

In 1 and 2,

R ¹ , R ² : a hydrogen atom, a methyl group or an organic group represented by the following 3

p: 0 or 1

X: the organic group shown in the following 4

Y: the organic group shown in the following 5

M ¹ : hydrogen atom, ammonium group, organic amine group, alkali metal or 1/2 equivalent of alkaline earth metal

[Chemical 3]-(CH ₂ ) _r -COOM ²

In 3, r: 0 or 1

M ² : hydrogen atom, ammonium group, organic amine group, alkali metal or 1/2 equivalent of alkaline earth metal

[化4]-(AO) _m -R ³ -

In 4,

AO: an alkylene group having 2 to 4 carbon atoms

m: an integer from 1 to 10

R ³ : an alkylene group, an aromatic ring group or an unsaturated hydrocarbon group which may also have a hetero atom

[Chemical 5]-(CH ₂ ) _s (CO) _t O(AO) _n -R ⁴

5,

s: an integer from 0 to 4

t:0 or 1

AO: an alkylene group having 2 to 4 carbon atoms

n: an integer from 0 to 300

R ⁴ : a hydrogen atom, an alkyl group having 1 to 22 carbon atoms or an aliphatic fluorenyl group having 1 to 22 carbon atoms (wherein, when n = 0, R ⁴ is an alkyl group having 1 to 22 carbon atoms or a carbon number of 1 to 22) Aliphatic thiol)

The dispersion-retaining agent for a hydraulic composition of the present invention (hereinafter referred to as "dispersion retention agent of the present invention") contains an ethylene-based copolymer obtained by the monomer A shown in the above-mentioned Chemical Formula 1 and the monomer B shown in the above Chemical Formula 2 a compound (hereinafter referred to as "ethylene-based copolymer P") and a vinyl-based copolymer obtained from the monomer A, the monomer B, and another monomer C copolymerizable with the above (hereinafter referred to as "ethylene" For the co-polymer Q").

First, the ethylene-based copolymer P will be described. The ethylene-based copolymer P is a vinyl-based copolymer obtained from the monomer A and the monomer B, and the ratio of the two is not particularly limited, and is preferably in the total constituent unit, and is derived from the monomer A. The ethylene-based copolymer having a mass average molecular weight of 8,000 to 200,000 is contained in a ratio of 1 to 99 mol% of the unit 1 and 99 mol% of the constituent unit derived from the monomer B (total 100 mol%).

In the above-mentioned 1 of the monomer A, R ¹ is a hydrogen atom, a methyl group or an organic group represented by the above 3; p is 0 or 1; X is an organic group represented by the above 4; M ¹ is a hydrogen atom, ammonium Base, organic amine group, alkali metal or 1/2 equivalent of alkaline earth metal. In the formula 3, r is 0 or 1; M ² is a hydrogen atom, an ammonium group, an organic amine group, an alkali metal or a 1/2 equivalent of an alkaline earth metal, and the organic group represented by the formula 3 is a carboxyl group or a methylene carboxyl group. .

Further, in the chemical formula 4, AO is an alkylene group having 2 to 4 carbon atoms; m is an integer of 1 to 10; and R ³ may have an alkylene group, an aromatic ring group or an unsaturated hydrocarbon having a hetero atom.

In the formula 4, the oxyalkylene group of AO may, for example, be an ethyloxy group, an oxypropyl group or an oxybutyl group, preferably an oxy group extending to an ethyl group, an oxypropyl group, and more preferably an ethyl group. . These lines may be one type or two or more types. m is an integer from 1 to 10, preferably an integer from 1 to 5, more preferably 1 or 2. The R ³ system may have a hetero atomic alkylene group, an aromatic ring group or an unsaturated hydrocarbon group, and the carbon number is not particularly limited. Examples of the alkylene group which may have a hetero atom include a methylene group, an ethyl group, a propyl group, a butyl group, a cyclohexyl group, an oxymethylene group, an oxyethyl group, an oxypropyl group, and an oxygen group. Base butyl and the like. Further, the aromatic ring group which may have a hetero atom may, for example, be a phenylene group, a benzylidene group, an anthranyl group, a thienyl group, a furyl group, a pyrrolyl group, a benzothienyl group, a benzofuranyl group or a benzo group. Pyrrolyl, three Base, imidazolyl, benzimidazolyl, triazolyl, thiadiazolyl, thiazolyl, and the like. Further, the unsaturated hydrocarbon group which may have a hetero atom may, for example, be an ethynyl group, a propynyl group or a butynyl group, or a group having a carbonyl group or an imino group before or after the above, and is preferably represented by the following formula 6 Organic base.

In the formula 6, the R ⁵ system may have a heteroalkyl group having 1 to 22 carbon atoms, an aromatic ring group or an unsaturated hydrocarbon group; u is an integer of 0 to 2; a M ³ hydrogen atom, an organic ammonium group, or an organic group; Base, alkali metal or 1/2 equivalent of alkaline earth metal.

In the formula 6, the R ^{5 group} may have a heteroalkyl group having 1 to 22 carbon atoms, an aromatic group or an unsaturated hydrocarbon group; and an alkylene group, an aromatic ring group or an unsaturated hydrocarbon group which may have a hetero atom, It is the same as R ³ in the above-mentioned Chemical Formula 4, and R ⁵ is preferably one of those having 1 to 22 carbon atoms, preferably 1 to 6 carbon atoms.

In the formula 1, 3, and 6, M ¹ , M ² , and M ³ are hydrogen atoms, ammonium groups, organic amine groups, alkali metals, or 1/2 equivalents of alkaline earth metals. These lines may be one type or two or more types. The ammonium group may, for example, be an ammonium group, a tetramethylammonium group or a tetrabutylammonium group. Further, examples of the organic amine group include an alkylamino group such as a methylamino group, a dimethylamino group, a trimethylamino group or a triethylamino group; an alkanolamine group such as a diethanolamine group or a triethanolamine group; a pyridinium group; An aromatic amine group such as lutidinium. Further, examples of the alkali metal include lithium, sodium, potassium, rubidium, and the like. Further, the alkaline earth metal system may, for example, be calcium, magnesium or barium. Among them, the case of the alkaline earth metal is 1/2 equivalent.

Specific examples of the monomer A described above include, for example, 2-propenyloxyethyl succinic acid, 2-methylpropenyloxyethyl succinic acid, 2-propenyl oxyethyl hexahydrophthalic acid, and 2 - propylene oxime oxime acid, and the like, and examples thereof include unsaturated carboxylic acid esters having a terminal hydroxyl group such as hydroxyethyl (meth) acrylate or polyoxyethylene mono (meth) acrylate, and two to four a condensate of a carboxylic anhydride. This condensate is obtained by condensation of a hydroxyl group-containing unsaturated carboxylic acid ester with a di-tetracarboxylic acid anhydride. Examples of the unsaturated carboxylic acid ester which can be used for the condensation include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, and hydroxybutyl methacrylate. Polyoxyalkylene mono(meth)acrylate and the like. Further, examples of the di-tetracarboxylic carboxylic anhydride which can be used in the condensation include succinic anhydride, maleic anhydride, trimellitic anhydride, cyclohexyl-1,2-dicarboxylic anhydride, and pyromellitic anhydride. As the monomer A, one type or two or more types of the condensate may be used, and a condensate of hydroxyethyl (meth)acrylate and a di-tetracarboxylic acid anhydride is preferable.

The above condensate can be obtained by a known method. This is, for example, a method in which an unsaturated carboxylic acid ester having a hydroxyl group at the terminal and a di- or tetracarboxylic acid anhydride are heated and stirred in the absence of a solvent; in the presence of a solvent and a condensing agent, the terminal is unsaturated with a hydroxyl group. A method of condensing a carboxylic acid ester with a di- or tetracarboxylic acid anhydride.

In the above-mentioned 2 of the monomer B, the R ² -based hydrogen atom, the methyl group or the organic group represented by the above 3; and the Y-based organic group represented by the above 5. In the case of 5, s is an integer of 0 to 4; t is 0 or 1; AO is an alkylene group having 2 to 4 carbon atoms; n is an integer of 0 to 300; R ⁴ is a hydrogen atom, and carbon number is 1 to 22 An alkyl group or an aliphatic fluorenyl group having 1 to 22 carbon atoms. However, when n = 0, R ⁴ is an alkyl group having 1 to 22 carbon atoms or an aliphatic fluorenyl group having 1 to 22 carbon atoms.

The R ⁴ in the formula 5 may, for example, be: 1) a hydrogen atom; 2) a methyl group, an ethyl group, a butyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, a decyl group, an undecyl group or a dodecyl group. , tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl, decyl, decyl, decyl, decyl,廿tetraalkyl, perylene penta, hexaalkyl, anthranylene, octadecyl, 2-methyl-pentyl, 2-ethyl-hexyl, 2-propyl-heptyl, 2- Butyl-octyl, 2-pentyl-indenyl, 2-hexyl-indenyl, 2-heptyl-undecyl, 2-octyl-dodecyl, 2-decyl-tridecyl a 2- to 12-alkyl group such as 2-mercapto-tetradecyl, 2-undecyl-pentadecyl or 2-dodecyl-hexadecyl; 3) formazan, Ethyl, propyl, butyl, hexyl, heptadecyl, octyl, decyl, decyl, hexadecane, octadecyl, hexadecane, fluorene An aliphatic fluorenyl group having 1 to 22 carbon atoms such as a carbene group or an octadecene group. Among them, R ^{4 is} preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aliphatic fluorenyl group having 1 to 4 carbon atoms.

The AO system in the correlation 5 is the same as the AO in the above-mentioned chemical 4, and the n is an integer of 0 to 300, and the (AO)n is preferably composed of 0 to 160 oxyethylene units and/or oxypropylene units ( Poly)oxyalkylene.

Specific examples of the monomer B described above include, for example, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, methyl acrylate, methyl methacrylate, acrylic acid. Propyl ester, propyl methacrylate, butyl acrylate, butyl methacrylate, α-allyl-ω-ethinyl-(poly)oxyethylene, α-allyl-ω-ethenyl- (poly)oxyethylene (poly)oxypropylene, α-allyl-ω-hydroxy-(poly)oxyethylene, α-allyl-ω-hydroxy-(poly)oxyethylene (poly)oxy Propylene, α-methacrylo-ω-hydroxy-(poly)oxyethylene, α-methylpropenyl-ω-methoxy-(poly)oxyethylene, α-methylpropenyl-ω-hydroxyl -(poly)oxyethylene (poly)oxypropene, α-methylpropenyl-ω-ethinyl-(poly)oxyethylene, α-(3-methyl-3-butenyl)-ω -hydroxy-(poly)oxyethylene, α-(3-methyl-3-butenyl)-ω-butoxy-(poly)oxyethylene, α-(3-methyl-3-butene -ω-hydroxy-(poly)oxyethylene (poly)oxypropene, α-(3-methyl-3-butenyl)-ω-ethinyl-(poly)oxyethylene (poly) Oxypropene, α-acryloyl-ω-hydroxy-(poly)oxyethylene, α-propyl Iridyl-ω-methoxy-(poly)oxyethylene, α-acrylinyl-ω-butoxy-(poly)oxyethylene, α-acryloyl-ω-methoxy-(poly Ethylene oxide (poly)oxypropylene, α-methylpropenyl-ω-hydroxy-(poly)oxyethylene, α-methylpropenyl-ω-methoxy-(poly)oxyethylene , α-methacryloyl-ω-butoxy-(poly)oxyethylene, α-acryloyl-ω-methoxy-(poly)oxyethylene (poly)oxypropylene, α-A Acrylmercapto-ω-hydroxy-(poly)oxyethylene (poly)oxypropylene, α-methacryloyl-ω-ethenyl-(poly)oxyethylene (poly)oxypropylene, and the like.

The monomer B of the formula 2 may be used alone or in combination of two or more. It is preferred to use two or more kinds of the monomers B, and more preferably, the monomer B in the case where the n in the group 5 is 0 to 8, and the n is a monomer B such as 9 to 160, and particularly preferably contains hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, methyl acrylate, One type or two or more types of monomer B and another monomer B are selected from methyl methacrylate, propyl acrylate, propyl methacrylate, butyl acrylate, and butyl methacrylate.

Next, the ethylene-based copolymer Q will be described. The ethylene-based copolymer Q is copolymerized with the other monomer C copolymerized in addition to the above-mentioned monomer A and monomer B. Examples of the other monomer C include: 1) allylsulfonic acid, methacrylic acidsulfonic acid, such alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, and the like; 2) acrylic acid, methacrylic acid , acrylic acid monomers such as crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, such alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, methyl esters, Ethyl ester, anhydrate, etc.; 3) (meth) acrylamide, N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, 2-(methyl) Acrylamide-2-methanesulfonic acid, 2-(methyl)acrylamidoxime-2-ethanesulfonic acid, 2-(methyl)acrylamidoxime-2-propanesulfonic acid, styrene, styrenesulfonic acid, etc. . Among them, the other monomer C is preferably an acrylic monomer.

In the vinyl copolymers P and Q, the monomer A ratio is preferably from 1 to 99 mol%, more preferably from 50 to 90 mol%, based on the total monomers used. Further, the ratio of the monomer B is preferably from 1 to 99 mol%, more preferably from 1 to 55 mol%. Further, the ratio of the other monomer C is preferably 50 mol% or less, more preferably 25 mol% or less, and particularly preferably 10 mol% or less.

The mass average molecular weight of the ethylene-based copolymers P and Q is preferably from 8,000 to 200,000, more preferably from 9000 to 150,000, and particularly preferably from 10,000 to 100,000. Further, in the present invention, the mass average molecular weight is a polyethylene glycol equivalent value measured by a gel permeation chromatography analyzer (hereinafter referred to as "GPC").

The ethylene-based copolymers P and Q to be used in the dispersion-retaining agent of the present invention can be obtained by a known method. This may be, for example, radical polymerization using water as a solvent, radical polymerization using an organic solvent as a solvent, radical polymerization without using a solvent, or the like. The radical polymerization initiator used in the radical polymerization may, for example, be a peroxide such as hydrogen peroxide, ammonium persulfate, sodium persulfate or potassium persulfate; or an azo compound such as azobisisobutyronitrile. At the polymerization reaction temperature, a radical is decomposed and a radical is generated, and a redox initiator which suitably uses a reducing agent together is also mentioned. In order to set the mass average molecular weight of the obtained ethylene-based copolymer to a desired range, a chain transfer agent can also be used. The chain transfer agent is not particularly limited as long as it can adjust the molecular weight of the ethylene-based copolymer, and a known chain transfer agent can be used. Specifically, for example, 1) mercaptoethanol, thioglycerol, indole acetic acid, mercaptopropionic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl acetate, and octyl 3-mercaptopropionate a mercaptan chain transfer agent such as 2-mercaptoethanesulfonic acid, n-dodecyl mercaptan, octyl mercaptan or thioglycolate; 2) carbon tetrachloride, carbon tetrabromide, dichloro Halides such as methane, bromoform and bromotrichloroethane; 3) unsaturated hydrocarbons such as α-methylstyrene dimer, α-terpinene, γ-terpinene, dipentene and terpinolene a compound; 4) a primary alcohol such as 2-aminopropan-1-ol; a secondary alcohol such as isopropanol; 5) a phosphorous acid, hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, etc., sulfurous acid, hydrogensulfite ( Hydrogen sulfite), disulfic acid, pyrosulfite, sodium sulfite, potassium sulfite, sodium hydrogen sulfite, potassium hydrogen sulfite, sodium disulfoxide, potassium disulfoxide, sodium metabisulfite, pyrosulfite Lower oxides such as potassium and salts thereof. The ethylene-based copolymers P and Q are obtained by anionic polymerization or cationic polymerization in addition to the radical polymerization described above, and examples of the initiator used in the polymerization include alkali metal and butyl lithium. , a Grignard reagent, a metal alkoxide, a boronic acid such as boron trifluoride; a Brilliant acid such as sulfuric acid, etc., preferably a method obtained by radical polymerization carried out in a solvent-free or aqueous solvent.

The dispersion-retaining agent of the present invention is used as a mixing agent when preparing a hydraulic composition (for example, mortar or concrete), and sufficiently prevents the loss of twist of the mortar or concrete prepared by using the composition. The materials used for the preparation of mortar and concrete are not particularly limited. For example, the bonding materials may be, for example, 1) ordinary Portland cement, early strength Portland cement, medium heat Portland cement, low heat Portland cement. Such as various Portland cement; 2) blast furnace cement, fly ash cement, ash cement and other mixed cement; 3) alumina cement. Further, the water/bonding material ratio is not particularly limited, and the water/bonding material is preferably 20 to 70%, more preferably 35 to 65%. Further, the type of the other dispersing agent used in the preparation of the mortar or the concrete is not particularly limited, and it is preferred to select one of the oxycarboxylic acid and the salt thereof, the polycarboxylic acid system, and the aromatic sulfonic acid system from the dispersing agent to be used together. Or more than two. Additives such as AE agent, defoamer, retarder, hardening accelerator, shrinkage inhibitor, and tackifier can also be used for mortar and concrete adjustment. The amount of the dispersion-retaining agent to be used in the present invention is not particularly limited, and is usually 0.005 to 1.0 part by mass, preferably 0.005 to 0.5 part by mass, more preferably 0.01%, based on 100 parts by mass of the binder. 0.5 parts by mass.

According to the dispersion retaining agent of the present invention, the loss of twist of the hydraulic composition can be sufficiently prevented. When the dispersion-retaining agent of the present invention is used in combination with the above-mentioned water-soluble ethylene-based copolymer of a hydraulic composition for a hydraulic composition, the effect of the two components can be multiplied, and the hydraulic composition can be provided with excellent fluidity over time.

 [Examples]  

Hereinafter, in order to make the structure of the present invention more specific, examples and the like are described, but the present invention is not limited to the embodiment. In addition, in the following examples, etc., unless otherwise stated, "%" means "% by mass", and "part" means "parts by mass".

Test distinction 1 (synthesis of monomer A)

‧ Synthesis of monomer (A-5)

127.7 g of hydroxyethyl acrylate, 192.1 g of trimellitic anhydride, 0.64 g of 4-methoxyphenol, and 300 mL of pyridine were placed in a reaction vessel equipped with a thermometer, a stirrer, and an air introduction tube, and uniformly dissolved while stirring. The temperature was raised while blowing dry air at a flow rate of 5 mL/min, and the reaction was carried out at 80 ° C for 8 hours. After completion of the reaction, the pyridine was distilled off by an evaporator to obtain a monoester (A-5) of hydroxyethyl acrylate and trimellitic acid.

‧ Synthesis of monomer (A-6)

130.1 g of hydroxypropyl acrylate, 110.1 g of succinic anhydride, and phenolic thiophene 0.13 g was placed in a reaction vessel equipped with a thermometer, a stirrer, and an air introduction tube, and the temperature was raised while blowing dry air at a flow rate of 3 mL/min, and the reaction was carried out at 100 ° C for 10 hours. After completion of the reaction, upon cooling, a monoester (A-6) of hydroxypropyl acrylate and succinic acid was obtained.

Test distinction 2 (synthesis of ethylene-based copolymers)

‧Example 1 {Synthesis of ethylene-based copolymer (EX-1), etc.}

17.2 g of ion-exchanged water and 174.2 g of α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53)oxyethylene were charged in a thermometer, a stirrer, and a dropping funnel. In the reaction vessel of the nitrogen introduction tube, the mixture was uniformly dissolved while stirring, and then the environment was subjected to nitrogen substitution, and the temperature of the reaction system was set to 65 ° C by a warm water bath. Then, 10.8 g of 3.5% hydrogen peroxide water was dropped over 3 hours, and an aqueous solution of 15.2 g of 2-propenyloxyethyl succinic acid and 28.3 g of hydroxyethyl acrylate was dropped over 17 hours in 174.2 g of ion-exchanged water. An aqueous solution of 1.0 g of L-ascorbic acid and 0.8 g of mercaptoethanol was dissolved in 7.3 g of ion exchange over 4 hours. Then, it was maintained at 65 ° C for 2 hours to complete the polymerization. After completion of the polymerization reaction, a 30% aqueous sodium hydroxide solution was added to adjust to pH 6, and the concentration was adjusted to 40% by ion-exchanged water to obtain an aqueous liquid of the reactant. This reaction product was made into the ethylene-type copolymer (EX-1).

‧Example 2 {Synthesis of ethylene-based copolymer (EX-2)}

206.5 g of ion-exchanged water, 151.7 g of α-methacryloyl-ω-methoxy-poly(n=23)oxyethylene, 23.3 g of 2-methylpropenyloxyethyl succinic acid, and hydroxyethyl acrylate 19.4 g of an ester and 2.3 g of 3-mercaptopropionic acid were placed in the same reaction vessel as in Example 1, and the environment was subjected to nitrogen substitution while stirring, and the temperature of the reaction system was 70 ° C by a warm water bath. The reaction was started by adding 3.0% aqueous sodium persulfate solution of 28.0 g. After 3 hours from the start of the reaction, 3.0% aqueous solution of 3.0% sodium persulfate was added and kept at 70 ° C for 3 hours. After the polymerization reaction was completed, 30% aqueous sodium hydroxide solution was added to adjust to pH 6, and ion exchange water was used. The concentration was adjusted to 40% to obtain an aqueous liquid of the reactant. This reaction product was made into the ethylene-type copolymer (EX-2).

‧Example 3 {Synthesis of ethylene-based copolymer (EX-3)}

27.9 g of ion-exchanged water and 173.0 g of α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53)oxyethylene were charged in the same reaction container as in Example 1. After uniformly dissolving while stirring, the environment was subjected to nitrogen substitution, and the temperature of the reaction system was set to 65 ° C by a warm water bath. Then, 10.8 g of 3.5% hydrogen peroxide water was dropped over 3 hours, and an aqueous solution of 43.2 g of 2-propenyloxyethyl succinic acid suspended in 173.0 g of ion-exchanged water was dropped over 3 hours, and it was dropped in ion exchange for 4 hours. An aqueous solution of 0.9 g of L-ascorbic acid and 0.7 g of 3-mercaptopropionic acid was dissolved in 6.1 g. Then, it was maintained at 65 ° C for 2 hours to complete the polymerization. After completion of the polymerization reaction, a 30% aqueous sodium hydroxide solution was added to adjust to pH 6, and the concentration was adjusted to 40% by ion-exchanged water to obtain an aqueous liquid of the reactant. This reaction product was made into the ethylene-type copolymer (EX-3).

‧Example 4 {Synthesis of ethylene-based copolymer (EX-4)}

36.4 g of ion-exchanged water and 173.5 g of α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53)oxyethylene were charged in the same reaction container as in Example 1. After uniformly dissolving while stirring, the environment was subjected to nitrogen substitution, and the temperature of the reaction system was set to 65 ° C by a warm water bath. Next, 9.8 g of 4.0% hydrogen peroxide water was added dropwise over 3 hours, and 15.2 g of 2-propenyloxyethyl succinic acid, 26.0 g of hydroxyethyl acrylate and 2.2 g of acrylic acid were dissolved in 164.8 g of ion-exchanged water over 3 hours. The aqueous solution was dissolved in an aqueous solution of 0.9 g of L-ascorbic acid and 1.1 g of 3-mercaptopropionic acid in 7.8 g of ion exchange over 4 hours. Then, it was maintained at 65 ° C for 2 hours to complete the polymerization. After completion of the polymerization reaction, a 30% aqueous sodium hydroxide solution was added to adjust to pH 6, and the concentration was adjusted to 40% by ion exchange water to obtain an aqueous liquid of the reactant. This reaction product was made into the ethylene-type copolymer (EX-4).

‧Examples 5 to 9 {Synthesis of ethylene-based copolymer (EX-5) to (EX-9)

In the same manner as in the case of Examples 1 to 4, the types, amounts, and the like of the monomers to be used were changed to those described in Table 1, and ethylene-based copolymers (EX-5) to (EX-9) were synthesized.

‧Comparative Example 1 {Synthesis of ethylene-based copolymer (CE-1)}

242.8 g of ion-exchanged water, 370.0 g of α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53)oxyethylene, and 0.7 g of acrylic acid were charged in the same manner as in Example 1. In the same reaction vessel, the mixture was uniformly dissolved while stirring, and the environment was subjected to nitrogen substitution, and the temperature of the reaction system was set to 60 ° C by a warm water bath. Next, 48.8 g of a 4.3% sodium persulfate aqueous solution was added dropwise over 3.5 hours, and an aqueous solution of 18.7 g of acrylic acid was dissolved in 21.6 g of ion-exchanged water over 3 hours, and 0.7 g of thioglycol was dissolved in 46.7 g of ion exchange over 3.5 hours. Aqueous solution. Then, it was maintained at 60 ° C for 2 hours to complete the polymerization. After completion of the polymerization reaction, a 30% aqueous sodium hydroxide solution was added to adjust to pH 6, and the concentration was adjusted to 40% by ion-exchanged water to obtain an aqueous liquid of the reactant. This reaction product was made into the ethylene-type copolymer (CE-1).

‧Comparative Example 2 {Adjustment of CE-2}

Sodium gluconate was adjusted to a concentration of 40% using ion-exchanged water.

The composition and the mass average molecular weight of each of the ethylene-based copolymers synthesized above were summarized in Table 1. In addition, water was removed from the aqueous solution of each of the ethylene-based copolymers, and then a solution of 5% was adjusted with heavy water, and it was confirmed by NMR measurement at 300 MHz that each monomer was polymerized. Further, the mass average molecular weight was measured by GPC and expressed in terms of polyethylene glycol.

in FIG. 1,

A-1: 2-propenyloxyethyl succinic acid

A-2: 2-Methylacryloyloxyethyl succinic acid

A-3: 2-propenyloxyethyl hexahydrophthalic acid

A-4: 2-propenyloxyethyl decanoic acid

A-5: monoester of hydroxyethyl acrylate and trimellitic acid

A-6: monoester of hydroxypropyl acrylate and succinic acid

M-1: α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53)oxyethylene

M-2: α-methacryloyl-ω-methoxy-poly(n=23)oxyethylene

M-3: α-methacryloyl-ω-methoxy-poly(n=45)oxyethylene

M-4: α-methacryloyl-ω-hydroxy-poly(n=113)oxyethylene

M-5: α-methacryloyl-ω-methoxy-poly(n=9)oxyethylene

M-6: hydroxyethyl acrylate

M-7: Methyl acrylate

M-8: Hydroxypropyl acrylate

C-1: Acrylic

C-2: methacrylic acid

Test Division 3 (Evaluation of dispersant for hydraulic composition)

‧Modulation of concrete

In the 55L forced double-shaft mixer, it is put into order: ordinary Putlan cement (made by Pacific Cement Co., Ltd., specific gravity = 3.16), fine aggregate (Dajingchuan water system sand, specific gravity = 2.58), and coarse aggregate (Okazaki gravel, Specific gravity = 2.68), after 5 seconds of hollow mixing, according to the target range of 21 ± 1.5cm, and the amount of air is 4.5 ± 0.5%, respectively: relative to ordinary Putlan cement, high performance AE water reduction The agent (CHUPOL® HP-11, hereinafter referred to as "HP-11" manufactured by Takeshi Oil Co., Ltd.) is 0.6 to 0.8%; the test distinguishes two synthetic ethylene-based copolymers (EX-1) from ordinary Portland cement. ~(EX-9) and (CE-1), (CE-2) 20% aqueous solution is 0.1 to 0.3%; AE agent (product name AE-300 manufactured by Takeshi Oil Co., Ltd.) becomes 0.005%; compared with the ordinary Portland cement, the defoaming agent (trade name: AFK-2, manufactured by Takemoto Oil Co., Ltd.) was mixed and put into water in a manner of 0.001%, and kneaded for 90 seconds. The unit amount of the concrete prepared according to this is as shown in Table 2.

[Table 2]

‧Evaluation

The turbidity, the amount of air, the compressive strength after 24 hours, and the bleeding rate of each concrete which were allowed to stand were measured every 30 minutes from the time of the kneading, and the results are shown in Table 3.

‧ Turbulence: Each concrete that was allowed to stand was measured in accordance with JIS-A1150 immediately after the kneading and every 30 minutes.

‧ Air volume: After each kneading, and every 30 minutes, the concrete for standing was measured according to JIS-A1128.

‧Compressive strength: According to JIS-A1108, the sample size was set to 100 mm in diameter × 200 mm in height, and the measurement was performed according to the age of the material for 24 hours.

‧ bleeding rate: measured according to JIS-A1123.

In Table 3,

HP-11 addition ratio (%): relative to the mass of ordinary Putlan cement with HP-11%

Addition ratio (%) of the ethylene-based copolymer: a test to distinguish 20% aqueous solution of two synthetic ethylene-based copolymers, etc., with respect to the mass% of ordinary Portland cement

As is apparent from the results of Table 3 corresponding to Tables 1 and 2, the dispersion-retaining agent according to the present invention can maintain the fluidity of the hydraulic composition for a long period of time without causing a hardening delay.

Claims (10)

A dispersion-retaining agent for a hydraulic composition, which comprises a vinyl-based copolymer obtained from the monomer A shown in the following formula 1 and the monomer B shown in the following formula 2; (In 1 and 2, R ¹ and R ^{2 are a} hydrogen atom, a methyl group or an organic group represented by the following 3: p: 0 or 1 X: an organic group Y represented by the following 4: 5 Show organic group M ¹ : hydrogen atom, ammonium group, organic amine group, alkali metal or 1/2 equivalent of alkaline earth metal) [Chemical 3]-(CH ₂ ) _r -COOM ² (in 3, r: 0 or 1 M ² : hydrogen atom, ammonium group, organic amine group, alkali metal or 1/2 equivalent of alkaline earth metal) [Chemical 4]-(AO) _m -R ³ - (in 4, AO: carbon number 2~ 4 oxyalkylene m: an integer of 1 to 10 R ³ : an alkylene group having an hetero atom, an aromatic ring group or an unsaturated hydrocarbon group) [5]-(CH ₂ ) _s (CO) _t O ( AO) _n -R ⁴ (in 5, s: an integer of 0 to 4 t: 0 or 1 AO: an alkyl group having 2 to 4 carbon atoms and an alkyl group n: an integer of 0 to 300 R ⁴ : a hydrogen atom, a carbon number An alkyl group of 1 to 22 or an aliphatic fluorenyl group having 1 to 22 carbon atoms (wherein, when n = 0, R ⁴ is an alkyl group having 1 to 22 carbon atoms or an aliphatic fluorenyl group having 1 to 22 carbon atoms)).  A dispersion-retaining agent for a hydraulic composition, which comprises the ethylene-based copolymer obtained from the monomer A of the claim 1, the monomer B of the claim 1, and the other monomer C copolymerizable with the monomers.   The dispersion-retaining agent for a hydraulic composition according to claim 1 or 2, wherein R ³ in the compound 4 is an organic group represented by the following 6: (Chem. 6, R ⁵ : an alkyl group having 1 to 22 carbon atoms which may have a hetero atom, an aromatic ring group or an unsaturated hydrocarbon group u: an integer of 0 to 2 M ³ : a hydrogen atom, an ammonium group, an organic amine group , alkali metal or 1/2 equivalent of alkaline earth metal). The dispersion-retaining agent for a hydraulic composition according to claim 1 or 2, wherein R ⁵ in the group 6 is an alkylene group having 1 to 6 carbon atoms, an aromatic ring group or an unsaturated hydrocarbon group.  The dispersion-retaining agent for a hydraulic composition according to claim 1 or 2, wherein the monomer A is a condensate of hydroxyethyl (meth)acrylate and a di-tetracarboxylic anhydride.    The dispersion-retaining agent for a water-hardening composition according to claim 1 or 2, wherein the ethylene-based copolymerization system has a mass average molecular weight of 8,000 to 200,000.    The dispersion-retaining agent for a hydraulic composition according to claim 3, wherein the ethylene-based copolymerization system is a total of 100, and the constituent unit derived from the monomer A and the constituent unit derived from the monomer B become 100 The % of the ear is contained in a ratio of 1 to 99 mol% of the constituent unit derived from the monomer A, and 1 to 99 mol% of the constituent unit derived from the monomer B.    The dispersion-retaining agent for a hydraulic composition according to claim 4, wherein the ethylene-based copolymerization system is a total of 100, and the constituent unit derived from the monomer A and the constituent unit derived from the monomer B become 100 The % of the ear is contained in a ratio of 1 to 99 mol% of the constituent unit derived from the monomer A, and 1 to 99 mol% of the constituent unit derived from the monomer B.    The dispersion-retaining agent for a hydraulic composition according to claim 5, wherein the ethylene-based copolymerization system is a total of 100, and the constituent unit derived from the monomer A and the constituent unit derived from the monomer B become 100 The % of the ear is contained in a ratio of 1 to 99 mol% of the constituent unit derived from the monomer A, and 1 to 99 mol% of the constituent unit derived from the monomer B.    The dispersion-retaining agent for a hydraulic composition according to claim 6, wherein the ethylene-based copolymerization system is a total of 100, and the constituent unit derived from the monomer A and the constituent unit derived from the monomer B become 100 The % of the ear is contained in a ratio of 1 to 99 mol% of the constituent unit derived from the monomer A, and 1 to 99 mol% of the constituent unit derived from the monomer B.