TWI721177B - 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 hydraulic compositions. Various dispersants are widely used in the preparation of hydraulic compositions such as mortar and concrete. However, generally, if a dispersant is used to prepare a hydraulic composition, it will cause a large slump loss (decrease in fluidity with time), and a decrease in workability and workability. The present invention relates to a dispersion-retaining agent for hydraulic compositions capable of sufficiently preventing slump loss.

Conventionally, a dispersant for a hydraulic composition composed of a water-soluble ethylene-based copolymer has been proposed as a self-possibly capable of preventing slump loss (for example, refer to Patent Documents 1 to 4). However, these conventional proposals have a problem that they cannot sufficiently prevent the slump loss of the prepared hydraulic composition. Therefore, it has also been proposed to use an anti-slump 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 slump loss of the prepared hydraulic composition cannot be sufficiently prevented.

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

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

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

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

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

The problem to be solved by the present invention is to provide a dispersion-retaining agent for a hydraulic composition that can maintain the fluidity of the hydraulic composition even after a long period of self-kneading, and has less delay in hardening.

However, the inventors of the present invention have intensively studied to solve the above-mentioned problems and found that specific monomers having carboxyl groups in the molecules, specific monomers having polyalkylene glycol residues in the molecules, and, if necessary, can be combined with these monomers. The ethylene-based copolymer obtained by copolymerizing other monomers copolymerized by the monomer can be suitably used as a dispersion-retaining agent for hydraulic compositions.

That is, the dispersion-retaining agent for hydraulic compositions of the present invention contains an ethylene-based copolymer obtained from the monomer A shown in Chemical 1 below and the monomer B shown in Chemical 2 below. In addition, the dispersion-retaining agent for hydraulic compositions of the present invention contains monomer A shown in the following chemical 1, monomer B shown in the following chemical 2, and other monomers copolymerizable with these monomers C ethylene-based copolymer obtained.

[化1]

In Chemical 1 and Chemical 2,

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

p: 0 or 1

X: Organic group shown in Chemical 4 below

Y: Organic group shown in Chemical 5 below

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

[化3]-(CH ₂ ) _r -COOM ²

In chemistry 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 the 4,

AO: oxyalkylene with carbon number 2~4

m: an integer from 1 to 10

R ³ : Alkylene group, aromatic ring group or unsaturated hydrocarbon group which may also have heteroatoms

[化5]-(CH ₂ ) _s (CO) _t O(AO) _n -R ⁴

In 5,

s: an integer from 0 to 4

t: 0 or 1

AO: oxyalkylene with carbon number 2~4

n: an integer from 0 to 300

R ⁴ ：Hydrogen atom, alkyl group with 1-22 carbons or aliphatic acyl group with 1-22 carbons (wherein, when n=0, R ⁴ is an alkyl group with 1-22 carbons or 1-22 carbons Aliphatic base)

The dispersion-retaining agent for hydraulic compositions of the present invention (hereinafter referred to as the "dispersion-retaining agent of the present invention") contains: an ethylene-based copolymer obtained from monomer A shown in Formula 1 above and monomer B shown in Formula 2 above Combinations (hereinafter referred to as "ethylene copolymer P"), and containing ethylene copolymers (hereinafter referred to as "ethylene copolymers") obtained from the monomer A, the monomer B, and other monomers C that can be copolymerized with these It is the copolymer Q").

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

In the above-mentioned chemical 1, which represents the monomer A, R ¹ is a hydrogen atom, a methyl group, or an organic group shown in the above-mentioned chemical 3; p is 0 or 1; X is an organic group shown in the above-mentioned chemical 4; M ¹ is a hydrogen atom, ammonium Group, organic amine group, alkali metal or 1/2 equivalent of alkaline earth metal. In compound 3, r is 0 or 1; M ² is a hydrogen atom, ammonium group, organic amine group, alkali metal or 1/2 equivalent of alkaline earth metal, and the organic group shown in compound 3 is specifically a carboxyl group or a methylene carboxyl group .

Furthermore, in Chemical 4, AO is an oxyalkylene group having 2 to 4 carbon atoms; m is an integer of 1-10; and R ³ is an alkylene group, aromatic ring group or unsaturated hydrocarbon that may also have a heteroatom.

基、咪唑基、苯并咪唑基、三唑基、噻二唑基、噻唑基等。又，亦可具有雜原子的不飽和烴基係可舉例如：乙炔基、丙炔基、丁炔基、在該等的前後具有羰基、亞胺基的基，較佳係下述化6所示有機基。 In Chemical 4, the oxyalkylene series of AO may include, for example, oxyethylene, oxypropylene, and oxybutylene, preferably oxyethylene, oxypropylene, and more preferably oxyethylene. . These systems may be one type or two or more types. m is an integer of 1-10, preferably an integer of 1-5, more preferably 1 or 2. R ³ is an alkylene group, an aromatic ring group or an unsaturated hydrocarbon group which may also have a hetero atom, and the carbon number is not particularly limited. The alkylene series that may also have heteroatoms include, for example: methylene, ethylene, propylene, butylene, cyclohexyl, oxymethylene, oxyethylene, oxyethylene, oxygen Base butyl and so on. In addition, aromatic ring groups that may have heteroatoms include, for example, phenylene, benzylidene, naphthyl, thienyl, furanyl, pyrrolyl, benzothienyl, benzofuranyl, and benzofuranyl. Pyrrolyl, three

Group, imidazolyl, benzimidazolyl, triazolyl, thiadiazolyl, thiazolyl, etc. In addition, the unsaturated hydrocarbon group that may have a hetero atom includes, for example, an ethynyl group, a propynyl group, a butynyl group, and a group having a carbonyl group and an imino group before and after these groups, preferably as shown in the following chemical 6 Organic base.

In compound 6, R ⁵ is a C1-C22 alkylene group, aromatic ring group or unsaturated hydrocarbon group that may also have heteroatoms; u is an integer of 0-2; M ³ is a hydrogen atom, organic ammonium group, organic Base, alkali metal or 1/2 equivalent of alkaline earth metal.

In compound 6, R ⁵ may also have heteroatomic alkylene, aromatic group or unsaturated hydrocarbon group with carbon number of 1-22; related to alkylene, aromatic ring group or unsaturated hydrocarbon group that may also have heteroatom, It is the same as ^{R 3} in the above-mentioned chemical 4, and ^{among these, R 5} is preferably one having 1 to 22 carbon atoms, and more preferably one having 1 to 6 carbon atoms.

In Chemical 1, Chemical 3, and Chemical 6, M ¹ , M ² , and M ³ are hydrogen atoms, ammonium groups, organic amine groups, alkali metals, or 1/2 equivalent of alkaline earth metals. These systems may be one type or two or more types. Examples of the ammonium group include an ammonium group, a tetramethylammonium group, and a tetrabutylammonium group. In addition, the organic amine group may include, for example, alkylamino groups such as methylamino, dimethylamino, trimethylamino, and triethylamino; alkanolamino groups such as diethanolamine and triethanolamine; pyridinium, diethanolamine, etc. Aromatic amino groups such as lutidinium. In addition, examples of the alkali metal system include lithium, sodium, potassium, and cesium. However, examples of the alkaline earth metal series include calcium, magnesium, and barium. Among them, the case of alkaline earth metals is 1/2 equivalent.

Specific examples of the monomer A described above include, for example, 2-propenyloxyethyl succinic acid, 2-methacryloyloxyethyl succinic acid, 2-propenyloxyethyl hexahydrophthalic acid, 2 -Acrylic oxyethyl phthalic acid, etc., but also for example: hydroxyethyl (meth)acrylate, polyoxyethylene mono(meth)acrylate and other unsaturated carboxylic acid esters with hydroxyl groups at the end, and two to four Condensate of carboxylic acid anhydride. This condensate is obtained by condensation of an unsaturated carboxylic acid ester having a hydroxyl group at the terminal and a di-tetracarboxylic acid anhydride. Examples of unsaturated carboxylic acid esters that can be used for condensation include: hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, Polyoxyalkylene mono(meth)acrylate and the like. In addition, examples of di-tetracarboxylic acid anhydrides that can be used in the condensation include succinic anhydride, maleic anhydride, trimellitic anhydride, cyclohexyl-1,2-dicarboxylic anhydride, pyromellitic anhydride, and the like. Monomer A can use one or two or more of these condensates, and it is preferably a condensate of hydroxyethyl (meth)acrylate and di-tetravalent carboxylic anhydride.

The above-mentioned condensate system can be obtained by a known method. This system can include, for example, the method of heating and stirring an unsaturated carboxylic acid ester with a hydroxyl group at the end and a di-tetracarboxylic acid anhydride in the absence of a solvent; in the presence of a solvent and a condensing agent, the unsaturated carboxylic acid ester with a hydroxyl group at the end is made unsaturated Carboxylic acid ester, method of condensing with di-tetrabasic carboxylic acid anhydride, etc.

In the above-mentioned chemical 2 of the monomer B, R ² is a hydrogen atom, a methyl group, or the organic group shown in the above-mentioned chemical 3; and Y is the organic group shown in the above-mentioned chemical 5. In chemical 5, s is an integer from 0 to 4; t is 0 or 1; AO is an oxyalkylene group with 2 to 4 carbons; n is an integer from 0 to 300; R ⁴ is a hydrogen atom and carbon number is 1 to 22 The alkyl group or the aliphatic aliphatic group with 1 to 22 carbon atoms. However, when n=0, R ⁴ is an alkyl group with 1 to 22 carbons or an aliphatic acyl group with 1 to 22 carbons.

Examples of the R ⁴ system in Compound 5 include: 1) hydrogen atom; 2) methyl, ethyl, butyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl , Tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosanyl group, hexadecyl group, dodecyl group, hexadecyl group, Tetradecyl, pentadecyl, hexadecyl, decane, decyl, 2-methyl-pentyl, 2-ethyl-hexyl, 2-propyl-heptyl, 2- Butyl-octyl, 2-pentyl-nonyl, 2-hexyl-decyl, 2-heptyl-undecyl, 2-octyl-dodecyl, 2-nonyl-tridecyl , 2-decyl-tetradecyl, 2-undecyl-pentadecyl, 2-dodecyl-hexadecyl and other alkyl groups with 1 to 22 carbon atoms; 3) Methyl, Acetyl, propionyl, butyryl, hexyl, heptadecyl, octyl, nonyl, decyl, hexadecyl, octadecyl, hexadecenyl, eicosanyl Aliphatic aliphatic groups with 1 to 22 carbon atoms such as carbenyl and octadecenyl. Among them, R ^{4 is} preferably a hydrogen atom, an alkyl group having 1 to 4 carbons, and an aliphatic acyl group having 1 to 4 carbons.

The AO in Correlation 5 is the same as the AO in Chemical 4, n is an integer from 0 to 300, and (AO) n is preferably composed of 0 to 160 oxyethylene units and/or oxypropylene units ( Poly)oxyalkylene.

Specific examples of monomer B described above include, for example, hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, methyl acrylate, methyl methacrylate, and acrylic acid. Propyl ester, propyl methacrylate, butyl acrylate, butyl methacrylate, α-allyl-ω-acetyl-(poly)oxyethylene, α-allyl-ω-acetyl- (Poly)oxyethylene (poly)oxypropylene, α-allyl-ω-hydroxy-(poly)oxyethylene, α-allyl-ω-hydroxy-(poly)oxyethylene (poly)oxy Propylene, α-methacryl-ω-hydroxy-(poly)oxyethylene, α-methacryl-ω-methoxy-(poly)oxyethylene, α-methacryl-ω-hydroxy -(Poly)oxyethylene (poly)oxypropylene, α-methacryl-ω-acetyl-(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) (Base)-ω-hydroxy-(poly)oxyethylene (poly)oxypropylene, α-(3-methyl-3-butenyl)-ω-acetyl-(poly)oxyethylene (poly) Propylene oxide, α-acryloyl-ω-hydroxy-(poly)oxyethylene, α-acryloyl-ω-methoxy-(poly)oxyethylene, α-acryloyl-ω-butoxy -(Poly)oxyethylene, α-acryloyl-ω-methoxy-(poly)oxyethylene (poly)oxypropylene, α-methacryloyl-ω-hydroxy-(poly)oxy Ethylene, α-methacryloyl-ω-methoxy-(poly)oxyethylene, α-methacryloyl-ω-butoxy-(poly)oxyethylene, α-acryloyl -ω-Methoxy-(poly)oxyethylene (poly)oxypropylene, α-methacryloyl-ω-hydroxy-(poly)oxyethylene (poly)oxypropylene, α-methpropylene Acetyl-ω-acetyl-(poly)oxyethylene (poly)oxypropylene and the like.

The monomer B shown in Chemical 2 can be used at least one type or two or more, preferably two or more types are used, and more preferably, it contains monomer B when n is 0~8 in Chemical 5, and one of monomer B in Chemical 5. When n is 9 to 160, two types of monomer B, such as monomer B, are preferably contained from hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, methyl acrylate, One or more monomers B and other monomers B are selected among 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 one that, in addition to the above-mentioned monomer A and monomer B, is capable of copolymerizing with other monomers C that can be copolymerized. Examples of the other monomer C series include: 1) allyl sulfonic acid, methacrylic acid, alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, etc.; 2) acrylic acid, methacrylic acid , Crotonic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid and other acrylic monomers, such alkali metal salts, alkaline earth metal salts, ammonium salts, amine salts, methyl esters, Ethyl, anhydrous, etc.; 3) (meth)acrylamide, N-methyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, 2-(methyl) Acrylamide-2-methanesulfonic acid, 2-(meth)acrylamide-2-ethanesulfonic acid, 2-(meth)acrylamide-2-propanesulfonic acid, styrene, styrenesulfonic acid, etc. . Among them, the other monomer C is preferably an acrylic monomer.

In the ethylene copolymers P and Q, in the total monomers used, the ratio of the monomer A is preferably 1 to 99 mol%, more preferably 50 to 90 mol%. In addition, the ratio of monomer B is preferably 1 to 99 mol%, more preferably 1 to 55 mol%. In addition, 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 8,000 to 200,000, more preferably 9,000 to 150,000, and particularly preferably 10,000 to 100,000. In the present invention, the mass average molecular weight is a polyethylene glycol conversion value measured by a gel permeation chromatography analyzer (hereinafter referred to as "GPC").

The ethylene copolymers P and Q used for the dispersion-retaining agent of the present invention can be obtained according to a known method. Examples of this system include radical polymerization using water as a solvent, radical polymerization using an organic solvent as a solvent, radical polymerization without using a solvent, and the like. Examples of radical polymerization initiators used in the radical polymerization include peroxides such as hydrogen peroxide, ammonium persulfate, sodium persulfate, potassium persulfate, and azo compounds such as azobisisobutyronitrile. Those that decompose and generate free radicals at the polymerization reaction temperature can also include, for example, a redox initiator in which a reducing agent is appropriately used together. In order to be able to set the mass average molecular weight of the obtained ethylene-based copolymer in a desired range, a chain transfer agent may also be used. The chain transfer agent is under the premise that the molecular weight of the ethylene-based copolymer can be adjusted, and the rest is not particularly limited, and well-known chain transfer agents can be used. Specific examples include: 1) Mercaptoethanol, thioglycerol, thioacetic acid, mercaptopropionic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid, octyl thioacetate, and octyl 3-mercaptopropionate , 2-mercaptoethanesulfonic acid, n-dodecyl mercaptan, octyl mercaptan, thioglycolate and other mercaptan chain transfer agents; 2) carbon tetrachloride, carbon tetrabromide, dichloro Methane, bromoform, bromotrichloroethane and other halides; 3) α-methylstyrene dimer, α-terpinene, γ-terpinene, dipentene, terpinolene and other unsaturated hydrocarbons Compounds; 4) Primary alcohols such as 2-aminopropane-1-ol, secondary alcohols such as isopropanol; 5) Phosphorous acid, hypophosphorous acid, sodium hypophosphite, potassium hypophosphite, etc., sulfurous acid, hydrogen sulfite ( hydrogen sulfite), dithiosulfinic acid, metabisulfite, sodium sulfite, potassium sulfite, sodium bisulfite, potassium bisulfite, sodium dithiosulfinate, potassium dithiosulfinate, sodium metabisulfite, metabisulfite Potassium and other low-level oxides and their salts. In addition to the free radical polymerization described above, the ethylene copolymers P and Q can also be obtained by anionic polymerization and cationic polymerization. The initiators used in these polymerizations include, for example, alkali metals and butyl lithium. , Grignard reagent, metal alkoxides, boron trifluoride and other Lewis acids; sulfuric acid and other Brunsted acids, etc., preferably obtained by free radical polymerization in a solvent-free or water solvent.

The dispersion-retaining agent of the present invention is used as a mixing agent when preparing a hydraulic composition (for example, mortar, concrete), and sufficiently prevents the slump loss of the mortar and concrete prepared by using it. There are no special restrictions on the materials used in the preparation of mortar and concrete. For example, the binding materials include: 1) Ordinary Portland Cement, Early Strength Portland Cement, Medium Heat Portland Cement, Low Heat Portland Cement Various portland cements; 2) blast furnace cement, fly ash cement, silica fume cement and other mixed cements; 3) alumina cement, etc. In addition, the ratio of water/binding material is not particularly limited, and the ratio of water/binding material is preferably 20~70%, more preferably 35-65%. In addition, there are no particular restrictions on the types of other dispersants used in the preparation of mortar and concrete, and it is preferable to select one from among the oxycarboxylic acids and their salts, polycarboxylic acids, and aromatic sulfonic acids of the combined dispersant. Or two or more. Additives such as AE agents, defoamers, retarders, hardening accelerators, shrinkage inhibitors, and tackifiers can also be used when adjusting mortar and concrete. The amount of the dispersion retainer used in the present invention is not particularly limited. Relative to 100 parts by mass of the binding material, it is usually 0.005~1.0 parts by mass, preferably 0.005~0.5 parts by mass, and more preferably 0.01~ 0.5 parts by mass.

According to the dispersion retaining agent of the present invention, the slump loss of the hydraulic composition can be sufficiently prevented. If the dispersion retaining agent of the present invention is used in combination with a conventionally proposed dispersant for hydraulic composition, such as the above-mentioned water-soluble vinyl copolymer, the effects of both are multiplied and the hydraulic composition can be imparted with excellent fluidity over time.

[Example]

Hereinafter, in order to make the structure of the present invention more concrete, examples are given for description, but the present invention is not limited to these examples. In addition, in the following examples, etc., unless otherwise stated, "%" means "mass %", and "parts" means "parts by mass".

Test Division 1 (Synthesis of Monomer A)

‧Synthesis of monomer (A-5)

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

‧Synthesis of monomer (A-6)

0.13g，裝填入具備有溫度計、攪拌機、及空氣導入管的反應容器中，一邊依3mL/分的流量吹入乾燥空氣一邊升溫，於100℃溫度下進行反應10小時。待反應結束後，經冷卻，獲得丙烯酸羥丙酯與琥珀酸的單酯體(A-6)。 Combine 130.1 g of hydroxypropyl acrylate, 110.1 g of succinic anhydride, and phenothi

0.13 g was charged into 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 a temperature of 100°C for 10 hours. After the reaction is completed, after cooling, the monoester of hydroxypropyl acrylate and succinic acid (A-6) is obtained.

Test Division 2 (Synthesis of ethylene-based copolymers)

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

Put 29.2g of ion-exchanged water and 174.2g of α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53)oxyethylene into a thermometer, agitator, and a drip funnel. After stirring and uniformly dissolving in the reaction vessel with the nitrogen introduction tube, the environment is replaced with nitrogen, and the temperature of the reaction system is set to 65°C using a warm water bath. Next, 10.8 g of 3.5% hydrogen peroxide water was dropped over 3 hours, and an aqueous solution of 15.2 g of 2-propenoxyethyl succinic acid and 28.3 g of hydroxyethyl acrylate was dropped and suspended in 174.2 g of ion-exchanged water over 3 hours. And an aqueous solution in which 1.0 g of L-ascorbic acid and 0.8 g of mercaptoethanol were dissolved in 7.3 g of ion exchange was dropped over 4 hours. Then, the temperature was maintained at 65°C for 2 hours to complete the polymerization reaction. After the polymerization reaction is completed, a 30% aqueous sodium hydroxide solution is added to adjust the pH to 6, and the concentration is adjusted to 40% with ion-exchanged water to obtain an aqueous liquid of the reactant. Let this reactant be an ethylene-type copolymer (EX-1).

‧Example 2 {Synthesis of ethylene 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-methacryloxyethyl succinic acid, and hydroxyethyl acrylate 19.4 g of ester and 2.3 g of 3-mercaptopropionic acid were charged into the same reaction vessel as in Example 1, and the atmosphere was replaced with nitrogen while stirring, and the temperature of the reaction system was set to 70°C in a warm water bath. A 3.0% sodium persulfate 28.0 g aqueous solution was added to start the reaction. After 3 hours from the start of the reaction, add 3.0% sodium persulfate 6.8g aqueous solution and keep it at 70°C for 3 hours. After the polymerization reaction is over, add 30% sodium hydroxide aqueous solution to adjust the pH to 6, and use ion-exchanged water The concentration was adjusted to 40% to obtain an aqueous liquid of the reactant. Let this reactant be an ethylene-type copolymer (EX-2).

‧Example 3 {Synthesis of Ethylene 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 into the same reaction vessel as in Example 1. After uniformly dissolving while stirring, the environment was replaced with nitrogen, and the temperature of the reaction system was set to 65°C using a warm water bath. Next, 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 was suspended in 173.0 g of ion-exchanged water and dropped over 4 hours. An aqueous solution of 0.9 g of L-ascorbic acid and 0.7 g of 3-mercaptopropionic acid is dissolved in 6.1 g. Then, the temperature was maintained at 65°C for 2 hours to complete the polymerization reaction. After the polymerization reaction is completed, a 30% sodium hydroxide aqueous solution is added to adjust the pH to 6, and the concentration is adjusted to 40% with ion-exchange water to obtain an aqueous liquid of the reactant. Let this reactant be an ethylene-based copolymer (EX-3).

‧Example 4 {Synthesis of Ethylene 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 into the same reaction vessel as in Example 1. After uniformly dissolving while stirring, the environment was replaced with nitrogen, and the temperature of the reaction system was set to 65°C using a warm water bath. Next, 9.8 g of 4.0% hydrogen peroxide water was dropped 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. An aqueous solution containing 0.9 g of L-ascorbic acid and 1.1 g of 3-mercaptopropionic acid was dissolved in 7.8 g of ion exchange and dropped over 4 hours. Then, the temperature was maintained at 65°C for 2 hours to complete the polymerization reaction. After the polymerization reaction is completed, a 30% aqueous sodium hydroxide solution is added to adjust the pH to 6, and the concentration is adjusted to 40% by ion exchange water to obtain an aqueous liquid of the reactant. Let this reactant be an ethylene-based copolymer (EX-4).

‧Example 5~9 {Synthesis of ethylene copolymer (EX-5)~(EX-9)}

In the same manner as in Examples 1 to 4, but changing the type and amount of monomers used as described in Table 1, ethylene copolymers (EX-5) to (EX-9) were synthesized.

‧Comparative Example 1 {Synthesis of Ethylene Copolymer (CE-1)}

242.8g of ion-exchanged water, 370.0g of α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53)oxyethylene, and 0.7g of acrylic acid were filled in as in Example 1. In the same reaction vessel, after uniformly dissolving while stirring, the environment was replaced with nitrogen, and the temperature of the reaction system was set to 60°C using a warm water bath. Next, 48.8 g of a 4.3% sodium persulfate aqueous solution was dropped over 3.5 hours, and an aqueous solution of 18.7 g of acrylic acid dissolved in 21.6 g of ion-exchanged water was dropped over 3 hours, and 0.7 g of mercaptoethanol was dissolved in 46.7 g of ion exchanged water over 3.5 hours. Aqueous solution. Then, it was maintained at 60°C for 2 hours to complete the polymerization reaction. After the polymerization reaction is completed, a 30% sodium hydroxide aqueous solution is added to adjust the pH to 6, and the concentration is adjusted to 40% with ion-exchange water to obtain an aqueous liquid of the reactant. This reactant was referred to as an ethylene-based copolymer (CE-1).

‧Comparative example 2 {adjustment of CE-2}

The concentration of sodium gluconate is adjusted to 40% with ion-exchanged water.

For each ethylene-based copolymer synthesized above, the composition and mass average molecular weight are summarized in Table 1. In addition, for each ethylene-based copolymer, after removing water from the aqueous liquid, it was adjusted to a 5% solution with heavy water, and the measurement was performed with 300 MHz NMR, and it was confirmed that each monomer was polymerized. In addition, the mass average molecular weight was measured by GPC and expressed in terms of polyethylene glycol.

in FIG. 1,

A-1: 2-Propyloxyethyl succinic acid

A-2: 2-Methacryloxyethyl succinic acid

A-3: 2-propenyloxyethyl hexahydrophthalic acid

A-4: 2-propenyloxyethyl phthalic 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-Methylpropenyl-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 Dispersants for Hydraulic Compositions)

‧Concrete Modification

Put in the 55L forced double-shaft mixer in order: ordinary portland cement (made by Pacific Cement Company, specific gravity=3.16), fine aggregate (Oigawa water system sand, specific gravity=2.58), and coarse aggregate (Okazaki crushed stone, Specific gravity=2.68), after 5 seconds of hollow mixing, the target slump is 21±1.5cm, and the air volume becomes 4.5±0.5%, respectively according to: Compared with ordinary portland cement, high-performance AE water reduction (Trade name CHUPOL® HP-11 manufactured by Takemoto Oil & Fat Co., Ltd., hereinafter referred to as "HP-11") becomes 0.6 to 0.8%; compared to ordinary portland cement, test division 2 synthetic ethylene copolymers (EX-1) ~(EX-9) and (CE-1), (CE-2) 20% aqueous solution becomes 0.1~0.3%; compared with ordinary portland cement, AE agent (trade name AE-300 manufactured by Takemoto Oil Co., Ltd.) becomes 0.005%; Compared with ordinary portland cement, the defoamer (trade name AFK-2 manufactured by Takemoto Oil & Fat Co., Ltd.) was kneaded so that 0.001% was added, water was added, and kneaded for 90 seconds. According to this, the unit quantity of the prepared concrete is sorted out as shown in Table 2.

[Table 2]

‧Evaluation

Every 30 minutes from just after mixing, the slump, air volume, compressive strength after 24 hours, and bleeding rate of each static concrete were measured as follows, and the results are summarized as shown in Table 3.

‧ Slump fluidity: Measured according to JIS-A1150 for each static concrete immediately after mixing and every 30 minutes.

‧Air volume: Measured according to JIS-A1128 for each static concrete immediately after mixing and every 30 minutes.

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

‧Bleeding rate: Measured according to JIS-A1123.

In Table 3,

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

Addition ratio of ethylene-based copolymer (%): Test division 2 The 20% aqueous liquid of synthetic ethylene-based copolymer, etc., relative to the mass% of ordinary portland cement

The results of Table 3 corresponding to Tables 1 and 2 show that the dispersion-retaining agent of the present invention does not cause hardening delay and can maintain the fluidity of the hydraulic composition for a long time.

Claims (7)

A dispersion-retaining agent for hydraulic compositions, containing an ethylene copolymer obtained from monomer A shown in Chemical 1 below and monomer B shown in Chemical 2 below;

(In Chemicals 1 and 2, R ¹ , R ² : a hydrogen atom, a methyl group, or an organic group shown in Chemical 3 below p: 0 or 1 X: an organic group Y shown in Chemical 4 below: Show organic group M ¹ : hydrogen atom, ammonium group, organic amine group, alkali metal or 1/2 equivalent of alkaline earth metal) [化3]-(CH ₂ ) _r -COOM ² (in Chemical 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 Chemical 4, AO: carbon number 2~ 4's oxyalkylene group m: 1 or 2 R ³ : alkylene group, aromatic ring group or unsaturated hydrocarbon group that may also have heteroatoms) [化5]-(CH ₂ ) _s (CO) _t O(AO) _n -R ⁴ (In Chemical 5, s: an integer from 0 to 4 t: 0 or 1 AO: an oxyalkylene group with 2 to 4 carbons n: an integer from 0 to 300 R ⁴ : hydrogen atom, carbon number 1~ 22 alkyl group or aliphatic acyl group with 1-22 carbons (wherein, when n=0, R ⁴ is an alkyl group with 1-22 carbons or aliphatic acyl group with 1-22)). A dispersion-retaining agent for a hydraulic composition contains an ethylene copolymer obtained from the monomer A of claim 1, the monomer B of claim 1, and other monomers C copolymerizable with these monomers. The dispersion-retaining agent for hydraulic composition of claim 1 or 2, wherein R ^{3 in} Chemical 4 is an organic group shown in Chemical 6 below:

(In Chemical 6, R ⁵ : Alkylene, aromatic ring group or unsaturated hydrocarbon group with 1 to 22 carbon atoms, which may also have heteroatoms, u: an integer of 0 to 2 M ³ : hydrogen atom, ammonium group, organic amine group , Alkali metals or 1/2 equivalent of alkaline earth metals). According to claim 3, the dispersion-retaining agent for a hydraulic composition, wherein R ⁵ in Chem 6 is an alkylene group having 1 to 6 carbon atoms, an aromatic ring group, or an unsaturated hydrocarbon group. The dispersion retainer for hydraulic composition of claim 1 or 2, wherein the monomer A is a condensate of hydroxyethyl (meth)acrylate and di-tetracarboxylic anhydride. Such as claim 1 or 2 of the dispersion retaining agent for hydraulic composition, wherein the ethylene copolymer system has a mass average molecular weight of 8,000 to 200,000. Such as the dispersion-retaining agent for hydraulic composition of claim 1, wherein the total constitutional unit of the ethylene copolymer system is 100 moles based on the constitutional unit derived from the monomer A and the constitutional unit derived from the monomer B Contains 1 to 99 mol% of structural units derived from monomer A and 1 to 99 mol% of structural units derived from monomer B.