TWI783106B - Additive for hydraulic composition and hydraulic composition - Google Patents

Abstract

The present invention provides an additive for a hydraulic composition, which can obtain sufficient fluidity, can use a dispersant and a thickener as a single liquid, and greatly reduces material segregation, that is, has high material segregation resistance.

The additive for a hydraulic composition and the hydraulic composition of the present invention contain, as component A, a polymer having a structural unit composed of acrylic acid and/or its salt and having a mass average molecular weight of not less than 100,000 and not more than 50,000,000, and An ethylene copolymer having specific structural units 1 and 2 and containing 1 to 99% by mass of the structural unit 1 and 1 to 99% by mass of the structural unit 2 is used as the B component.

Description

Additive for hydraulic composition and hydraulic composition

The present invention relates to an additive for hydraulic composition. More specifically, it relates to an additive for hydraulic compositions that has good fluidity, can use a dispersant and a thickener as a single liquid, and has high resistance to material segregation, and can be used in cement compositions and the like.

Conventionally, lignosulfonic acid-based dispersants, naphthalenesulfonic acid-based dispersants, melaminesulfonic acid-based dispersants, or polycarboxylic acid-based dispersants have been used to impart fluidity to hydraulic compositions such as mortar and concrete. agent as a dispersant. In recent years, in order to improve filling properties, labor saving, and improve workability, there are more and more opportunities to use hydraulic compositions that further improve fluidity. As such a hydraulic composition, for example, high-fluidity concrete such as high-flow concrete having a slump of about 500 to 700 mm or medium-flow concrete having a slump of about 350 to 500 mm can be used.

Various techniques have been proposed in order to obtain such a hydraulic composition. For example, Patent Document 1 proposes to impart fluidity to concrete by using a specific polycarboxylic acid-based dispersant and a mixture of a copolymer of a carboxylic acid monomer and a (meth)acrylic acid ester. and resistance to material segregation. Furthermore, Patent Document 1 discloses that a specific polycarboxylic acid-based dispersant and a copolymer of a carboxylic acid monomer and a (meth)acrylic ester can be combined and supplied as a one-liquid type mixing agent as raw material components.

Also, Patent Document 2 proposes that concrete with high filling properties and high fluidity can be obtained by using specific low-substituted hydroxypropyl cellulose.

[Prior Art Literature]

patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2001-89212

Patent Document 2: Japanese Patent Application Laid-Open No. 4-139047

A thickener is used to reduce material segregation of the hydraulic composition. However, when a thickener and a dispersant are used together, there is a problem that if there is too much thickener, sufficient fluidity cannot be obtained even if the amount of the dispersant is increased, and if there is little thickener, sufficient fluidity cannot be obtained. Reduce material segregation.

Also, when low-substituted hydroxypropyl cellulose is used, there is a problem that it cannot be mono-liquidized as an aqueous solution because of low compatibility with dispersant components.

The techniques described in Patent Documents 1 and 2 cannot solve these problems. Therefore, the problem to be solved by the present invention is to provide an additive for a hydraulic composition, which can obtain sufficient fluidity, and can use a dispersant and a thickener as a single liquid, and greatly reduce material segregation, that is, High resistance to material segregation.

As a result of studies conducted by the present inventors to solve the above-mentioned problems, it was found that the use of an additive for a hydraulic composition having a specific polymer is suitable. According to the present invention, the following additives for hydraulic compositions are provided.

[1] An additive for a hydraulic composition comprising the following component A and the following component B; component A: has a structural unit composed of acrylic acid and/or its salt, and has a mass average molecular weight of 100,000 to 50,000,000 Component B: an ethylene copolymer having the following constituent unit 1 and constituent unit 2 in the molecule, and containing 1 to 99% by mass of constituent unit 1 and 1 to 99% by mass of constituent unit 2; constituent unit 1 : a structural unit formed by the following monomer 1; structural unit 2: a structural unit formed by a carboxylic acid monomer having a vinyl group in the molecule; monomer 1: an unsaturated (poly ) alkanediol:

In formula (1), R ¹ , R ² and R ³ are the same or different groups, and are selected from at least one of the organic groups represented by hydrogen atom, methyl group and -(CH ₂ )rCOOM, and wherein R ^1. At least one of R ² and R ³ represents a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group with 1 to 20 carbons, and R ⁵ O represents 1 of an oxyalkylene group with 2 to 4 carbons One or more kinds, p represents an integer from 0 to 5, q represents an integer from 0 or 1, m represents an integer from 1 to 300, r represents an integer from 0 to 2, and M represents a hydrogen atom or a metal atom.

[2] The additive for hydraulic compositions according to [1], wherein the component B is an ethylene copolymer further containing 0 to 30% by mass of the following structural unit 3; and the constituent unit formed by the monomer 3 copolymerized with the carboxylic acid monomer.

[3] The additive for a hydraulic composition according to [1] or [2], wherein the mass % of the component A relative to the component B is 0.01 to 1 mass %.

[4] The additive for a hydraulic composition according to any one of the above [1] to [3], wherein the mass average molecular weight of the component A is not less than 500,000 and not more than 10,000,000.

[5] The additive for a hydraulic composition according to any one of [1] to [4], which is used in a hydraulic composition with a water binder ratio of 35 to 65% and a slump of 35 to 70 cm .

[6] A hydraulic composition containing the additive for a hydraulic composition according to any one of [1] to [5].

[7] The hydraulic composition according to [6], which further contains a binder.

[8] The hydraulic composition according to [7], wherein the total mass parts of the component A and the component B is 0.1 to 2 parts by mass with respect to 100 parts by mass of the binder.

According to the additive for hydraulic compositions of the present invention, sufficient fluidity can be obtained, and the dispersant and thickener can be used as a single liquid, and material segregation can be greatly reduced, that is, material segregation resistance can be improved. Effect.

Embodiments of the present invention will be described below. However, the present invention is not limited to the following embodiments. Therefore, it should be understood that appropriate changes, improvements, and the like can be added to the following embodiments based on the general knowledge of practitioners without departing from the gist of the present invention. In addition, in the following examples etc., unless otherwise stated, % means mass %, and a part means a mass part.

The additive for hydraulic compositions of this embodiment is an additive for hydraulic compositions containing A component and B component.

The A component used for the additive for hydraulic compositions of this embodiment is a polymer which has the structural unit which consists of acrylic acid and/or its salt. Here, the type of acrylate is not particularly limited, and examples thereof include alkali metal salts such as sodium or potassium salts, alkaline earth metal salts such as calcium or magnesium salts, ammonium salts, diethanolamine salts, or triethanolamine salts. Amine salts, etc. From the viewpoint of ease of use and ease of acquisition, sodium salts and ammonium salts are preferred, and sodium salts are more preferred. Moreover, acrylic acid and/or its salt may be only 1 type, and may be 2 or more types.

The lower limit of the mass average molecular weight of the polymer of component A used in the additive for the hydraulic composition of this embodiment is 100,000 or more, preferably 500,000 or more, more preferably More than 1,000,000, more preferably more than 2,000,000, more preferably more than 3,000,000; the upper limit is less than 5,000,000, preferably less than 4,000,000, more preferably less than 3,000,000, more preferably less than 2,000,000, and more preferably less than 1,000,000.

Component B used in the additive for the hydraulic composition of this embodiment is an ethylene copolymer having the structural unit 1 and the structural unit 2 in the molecule.

The constituent unit 1 is formed from the monomer 1 . Monomer 1 is an unsaturated (poly)alkylene glycol represented by the following formula (1).

In formula (1), R ¹ , R ² and R ³ are mutually different groups, and are selected from at least one type of organic groups represented by hydrogen atom, methyl group and -(CH ₂ )rCOOM, wherein R ¹ , At least one of R2 and ^R3 represents a ^hydrogen atom or a methyl group. R ⁴ represents a hydrogen atom or a hydrocarbon group with 1 to 20 carbons. As such a hydrocarbon group, a methyl group, an ethyl group, a propyl group, a butyl group, etc. are mentioned. R ⁵ O represents one or more kinds of oxyalkylene groups having 2 to 4 carbon atoms. As such an oxyalkylene group, an oxyethylene group, an oxypropylene group, etc. are mentioned. In the case of two or more kinds of oxyalkylene groups, any addition form such as random addition, block addition, and alternate addition may be used. p represents an integer from 0 to 5, q represents 0 or 1, m represents an integer from 1 to 300, r represents an integer from 0 to 2, and M represents a hydrogen atom or a metal atom.

Examples of such monomers 1 include α-vinyl-ω-hydroxy (poly)oxybutylene (poly)oxyethylene, α-allyl-ω-methoxy-(poly)oxyethylene, α -Allyl-ω-methoxy-(poly)oxyethylene (poly)oxypropylene, α-allyl-ω-hydroxyl-(poly)oxyethylene, α-allyl-ω-hydroxyl-(poly ) oxyethylene (poly)oxypropylene, α-methallyl-ω-hydroxyl-(poly)oxyethylene, α-methallyl-ω-methoxy-(poly)oxyethylene, α-form Allyl-ω-hydroxy-(poly)oxyethylene (poly)oxypropylene, α-methallyl-ω-acetyl-(poly)oxyethylene, α-(3-methyl-3- Butenyl)-ω-hydroxy-(poly)oxyethylene, α-(3-methyl-3-butene base)-ω-butoxy-(poly)oxyethylene, α-(3-methyl-3-butenyl)-ω-hydroxy-(poly)oxyethylene (poly)oxypropylene, α-(3- Methyl-3-butenyl)-ω-acetyl-(poly)oxyethylene(poly)oxypropylene, α-acryl-ω-hydroxy-(poly)oxyethylene, α-acryl-ω -Methoxy-(poly)oxyethylene, α-acryl-ω-butoxy-(poly)oxyethylene, α-acryl-ω-methoxy-(poly)oxyethylene (poly)oxy Propylene, α-methacryl-ω-hydroxy-(poly)oxyethylene, α-methacryl-ω-methoxy-(poly)oxyethylene, α-methacryl-ω- Butoxy-(poly)oxyethylene, α-acryl-ω-methoxy-(poly)oxyethylene (poly)oxypropylene, α-methacryl-ω-hydroxy-(poly)oxyethylene (Poly)oxypropylene, α-methacryl-ω-acetyl-(poly)oxyethylene (poly)oxypropylene; unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid and Monoesters of (poly)oxyethylene; monoesters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid with (poly)oxyethylene (poly)oxypropylene.

The constitutional unit 2 is formed of a carboxylic acid monomer. The carboxylic acid monomer system here is a monomer that does not have an ester group or an amide group. The carboxylic acid monomer has a vinyl group in its molecule. Examples of such carboxylic acid monomers include (meth)acrylic acid, crotonic acid, maleic acid (anhydride), itaconic acid (anhydride), fumaric acid, and salts thereof. The salt is not particularly limited, and examples thereof include alkali metal salts such as sodium salts and potassium salts; alkaline earth metal salts such as calcium salts and magnesium salts; and amine salts such as ammonium salts, diethanolamine salts, and triethanolamine salts. Among them, sodium salt and calcium salt are preferred.

The ethylene copolymer of the component B used in the additive for hydraulic compositions of this embodiment may further contain the structural unit 3 as an arbitrary structural unit in a molecule|numerator. The constituent unit 3 can be formed from the monomer 3 copolymerizable with the monomer 1 and the carboxylic acid monomer.

Monomer 3 is not particularly limited as long as it can be copolymerized with monomer 1 and a carboxylic acid monomer, and examples thereof include alkyl (meth)acrylates such as methyl acrylate, methyl methacrylate, and butyl acrylate. Monomers; unsaturated amides such as (meth)acrylamide and N,N-dimethyl(meth)acrylamide; unsaturated cyanides such as (meth)acrylonitrile; maleic acid or Monoesters of unsaturated dicarboxylic acids such as fumaric acid and alkyl or alkenyl alcohols with 1 to 22 carbon atoms; or unsaturated dicarboxylic acids such as maleic acid or fumaric acid and (poly) Alkanediol or unsaturated dicarboxylic acid esters such as monoester or diester of alkyl or alkenyl alcohols with 1 to 22 carbons; unsaturated carboxylic acid or unsaturated dicarboxylic acid with 1 to 22 carbons Amide monomers such as monoamides or diamides of amines; amide monomers such as monoamides or diamides of unsaturated carboxylic acids or unsaturated dicarboxylic acids and amines with 1 to 22 carbon atoms Reaction products of (meth)acrylic acid obtained by adding ethylene oxide or propylene oxide to nitrogen atoms having active hydrogen in those obtained by condensation of alkyl dicarboxylic acids and polyethylene polyamines; not Monoamides or diamides of saturated carboxylic acids or unsaturated dicarboxylic acids and amines with a carbon number of 1 to 22, such as amide monomers; add ethylene oxide or propylene oxide to make alkyl dicarboxylates Those formed by the condensation of acid and polyethylene polyamine, which have nitrogen atoms with active hydrogen, react with glycidyl (meth)acrylate, that is, polyamide polyamine monomers; composed of (methyl) Sulfonic acid monomers composed of allyl sulfonic acid or ethylene sulfonic acid and their salts; 2-(methacryloxy)ethyl phosphate or bis[2-(methacrylic acid) Phosphoric acid-based monomers composed of acyloxy)ethyl]esters and their salts, etc.

Component B used in the hydraulic composition additive of this embodiment contains 1 to 99% by mass of the constituent unit 1, preferably 70 to 99% by mass, more preferably 75 to 99% by mass, and further Preferably, it contains 80-99% by mass; it contains 1-99% by mass of the constituent unit 2, preferably contains 1-30% by mass, more preferably contains 25-99% by mass, and is still more preferably contains 1-20% by mass. In addition, in the component B used in the hydraulic composition additive of the present embodiment, it is preferable to contain 0 to 30% by mass of the constituent unit 3, more preferably to contain 0 to 20% by mass, and even more preferably to contain 0 to 30% by mass. 10% by mass, more preferably 0 to 5% by mass.

In component B used in the additive for hydraulic compositions of this embodiment, the total of the constituent units 1 and 2 is preferably at least 80% by mass, more preferably at least 85% by mass, and still more preferably at least 90% by mass. , more preferably more than 95% by mass.

The mass average molecular weight of component B used in the hydraulic composition additive of this embodiment can be measured by gel permeation chromatography, and is preferably 2,000 to 500,000 in terms of polyethylene glycol, more preferably 5,000 to 200,000 , preferably 10000~100000.

This B component can be obtained by conventional free radical polymerization. For example, it can be manufactured by various methods. Among them, methods performed by radical polymerization using water in a solvent, radical polymerization using an organic solvent in a solvent, and solventless radical polymerization are exemplified. The reaction temperature in the radical polymerization is preferably from 0 to 120°C, more preferably from 20 to 100°C, and still more preferably from 50 to 90°C. The radical polymerization initiator used for radical polymerization includes peroxides such as hydrogen peroxide, ammonium persulfate, sodium persulfate, and potassium persulfate, or 2,2-azobis(2-formamidine The type of azo compounds such as 2,2-azobis(isobutyronitrile) and 2,2-azobis(isobutyronitrile) is not particularly limited as long as it decomposes at the polymerization reaction temperature to generate free radicals. These can also be used as reducing substances such as sulfite and ascorbic acid, and can also be used as a redox initiator in combination with an amine or the like. In order to make the mass average molecular weight of the obtained B component within the expected range, chains of 2-mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thioglycolic acid, thioglycerol, thiomalic acid, etc. transfer agent. These radical polymerization initiators, reducing substances, and chain transfer agents may be used alone or in combination of two or more.

In the hydraulic composition additive of this embodiment, the concentration of A component and B component is not particularly limited, but from the viewpoint of obtaining sufficient fluidity and sufficient material segregation inhibiting effect, the concentration of A component relative to B The mass % of a component is preferably 0.01-1 mass %, More preferably, it is 0.02-1 mass %, More preferably, it is 0.05-0.5 mass %.

Next, the hydraulic composition of this embodiment is demonstrated. The hydraulic composition of this embodiment contains the additive for hydraulic compositions of this embodiment.

In the method of adding the additive for hydraulic compositions to the hydraulic composition, A component and B component may be added independently, respectively, and may add simultaneously. Components A and B may be added to the hydraulic composition slurry as powders, and components A and B may be dispersed or dissolved in a liquid anti-shrinkage agent or a liquid antifoaming agent. Add it to the hydraulic composition slurry, and also in the state where the A component and the B component are dissolved in water Add to hydraulic composition mud.

In addition, when the ethylene copolymer of component B is used as an aqueous solution, the pH of the 1% by mass aqueous solution of component B is preferably from 2 to 7, more preferably 2 from the viewpoint of compatibility between component A and component B. ~6, preferably 2~5.

The hydraulic composition of this embodiment is prepared by using the additives for the hydraulic composition of this embodiment described above, and is preferably a cement composition such as cement slurry, mortar, and concrete. The cement composition is made of at least cement as a binder, but cement can also be used alone, and cement and pozzolanic substances or latent hydraulic fine powder mixed materials can also be used together. Examples of such cement include various Portland cements such as ordinary Portland cement, early-strength Portland cement, medium-heat Portland cement, and low-heat Portland cement, blast furnace cement, fly ash cement, and silica fume. Various mixed cements such as cement. Moreover, as a fine powder mixing material, blast furnace stone fine powder, silica fume, fly ash, etc. are mentioned.

It is also preferable that the hydraulic composition of this embodiment contains aggregates. Any appropriate aggregate such as fine aggregate or coarse aggregate can be used as the aggregate. Among such aggregates, examples of fine aggregates include river sand, mountain sand, land sand, silica sand, crushed sand, and blast furnace stone fine aggregates, and examples of coarse aggregates include river gravel and mountain gravel. , land gravel, crushed stone, blast furnace stone coarse aggregate, etc.

In the hydraulic composition of this embodiment, the total mass parts of components A and B are preferably 0.1 to 2 parts by mass, more preferably 0.1 to 1.5 parts by mass, and even more preferably 0.1 parts by mass relative to 100 parts by mass of the binder. ~1 part by mass.

In the range that does not impair the effect, the hydraulic composition of this embodiment can be suitably contained: for example, an AE adjuster composed of an anionic surfactant, such as an oxyalkylene-based antifoaming agent, such as an oxycarboxylic acid Retarders composed of salts, hardening accelerators composed of alkanolamines, shrinkage reducers composed of polyoxyalkylene alkyl ethers, preservatives composed of isothiazoline compounds, For example, waterproofing agents composed of higher fatty acid derivatives, such as Rust inhibitors composed of nitrates, etc.

The hydraulic composition of this embodiment is easily affected by the fluidity of clay. It is preferably used when the water-binder ratio is 35~65%, more preferably 40~65%, and even more preferably 40~60%. used in . In addition, the water binder ratio refers to the mass parts of water with respect to 100 mass parts of binders such as cement in the hydraulic composition, and when water is 50 mass parts, the water binder ratio is 50%.

From the viewpoint of filling properties in formwork and the like, the hydraulic composition of this embodiment has a slump fluidity of preferably 350 to 700 mm, more preferably 400 to 700 mm, and still more preferably 450 to 700 mm. In addition, the slump refers to the diameter spread when the hydraulic composition such as concrete is filled into the slump cone and the cone is lifted by the method of slump measurement. The slump fluidity can be measured according to JIS-A1150, for example.

[Example]

Test category 1 (polymer of acrylic acid and/or its salt as component A)

A summary of the polymers of acrylic acid and/or its salts used is shown in Table 1.

In Table 1,

A-1: Sodium polyacrylate (Aron A-20P-X manufactured by Toa Gosei Co., Ltd. with a molecular weight of 5 million)

A-2: Polyacrylic acid (1,000,000 polyacrylic acid manufactured by Wako Pure Chemical Industries, Ltd.)

A-3: Polyacrylic acid (250,000 polyacrylic acid manufactured by Wako Pure Chemical Industries, Ltd.)

Ar-1: polyacrylic acid (25,000 polyacrylic acid manufactured by Wako Pure Chemical Industries, Ltd.)

Ar-2: Sodium polyacrylate (completely neutralized polyacrylic acid 5,000 manufactured by Wako Pure Chemical Industries, Ltd. with 30% aqueous sodium hydroxide solution)

R-3: Hydroxypropylmethylcellulose (Metolose Hi90SH30000 manufactured by Shin-Etsu Chemical Co., Ltd.)

R-4: Hydroxypropylmethylcellulose (Metolose Hi90SH100000 manufactured by Shin-Etsu Chemical Co., Ltd.)

d-1: Structural unit formed of sodium acrylate

d-2: Structural unit composed of acrylic acid

d-3: Structural unit composed of acrylic acid

d-4: Structural unit composed of acrylic acid

d-5: Constituent unit formed of sodium acrylate

Test category 2 (manufacture of ethylene copolymer as component B)

Production example 1 (production of ethylene copolymer (B-1))

Put 250 g of distilled water and 330 g of α-(3-methyl-3-butenyl)-ω-hydroxyl-poly(n=50) oxyethylene into a reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, and a nitrogen introduction tube ( The same container was used hereinafter), and after stirring to dissolve uniformly, the gas atmosphere was replaced with nitrogen, and the temperature of the reaction system was maintained at 65° C. with a warm water bath. Next, 16 g of 1% hydrogen peroxide water was dripped over 3 hours, and at the same time, an aqueous solution obtained by uniformly dissolving 30 g of acrylic acid in 80 g of ion-exchanged water was dripped over 3 hours, and at the same time, 2 g of ascorbic acid and An aqueous solution obtained by dissolving 3 g of thioglycolic acid in 14 g of ion-exchanged water. Thereafter, the temperature of the reaction system was maintained at 65° C. for 2 hours to complete the polymerization reaction. Thereafter, a 30% aqueous sodium hydroxide solution was added to the reaction system to adjust the pH to 3, and the concentration was adjusted to 40% with ion-exchanged water to obtain a reaction mixture. The reaction mixture was analyzed by gel permeation chromatography (GPC), and the mass average molecular weight was 35,000. take the reactant as Ethylene copolymer (B-1).

Production example 2 (production of ethylene copolymer (B-2))

150 g of distilled water was placed in the reaction container, the gas atmosphere was replaced with nitrogen, and the temperature of the reaction system was kept at 60° C. under the nitrogen atmosphere. Next, 150 g of distilled water, 20 g of methacrylic acid, 320 g of α-hydroxy-ω-methacryl-poly(n=2)propylene poly(n=113)oxyethylene, 10 g of ethyl hydroxyacrylate and 3-mercaptopropyl 3.5 g of the acid was uniformly mixed to prepare an aqueous monomer mixture solution. The monomer mixture aqueous solution and 24 g of a 10% sodium persulfate aqueous solution were simultaneously dropped into a reaction vessel over 4 hours to perform a radical copolymerization reaction, and then 6 g of a 10% sodium persulfate aqueous solution was dropped over 1 hour to perform a reaction. Thereafter, the temperature of the reaction system was maintained at 60° C. for 1 hour to perform a radical copolymerization reaction. Next, after cooling the reaction system to room temperature, an aqueous sodium hydroxide solution was added to adjust the pH to 5, and the concentration was adjusted to 40% with distilled water to obtain a reaction mixture. The reaction mixture was analyzed by gel permeation chromatography (GPC), and the mass average molecular weight was 43,000. This reaction mixture was referred to as an ethylene copolymer (B-2).

Production example 3 (production of ethylene copolymer (B-3))

150 g of distilled water was placed in the reaction container, the gas atmosphere was replaced with nitrogen, and the temperature of the reaction system was kept at 60° C. under the nitrogen atmosphere. Next, 150 g of distilled water, 35 g of methacrylic acid, 300 g of α-methoxy-ω-methacryl-poly(n=23)oxyethylene, 5 g of methyl acrylate and 3.5 g of 3-mercaptopropionic acid were uniformly mixed, To prepare an aqueous monomer mixture solution. The monomer mixture aqueous solution and 24 g of a 10% sodium persulfate aqueous solution were simultaneously dropped into a reaction vessel over 4 hours to perform a radical copolymerization reaction, and then 6 g of a 10% sodium persulfate aqueous solution was dropped over 1 hour to perform a reaction. Thereafter, the temperature of the reaction system was maintained at 60° C. for 1 hour to perform a radical copolymerization reaction. Next, after cooling the reaction system to room temperature, an aqueous sodium hydroxide solution was added to adjust the pH to 4, and the concentration was adjusted to 40% with distilled water to obtain a reaction mixture. The reaction mixture was analyzed by gel permeation chromatography (GPC), and the mass average molecular weight was 43,000. This reaction mixture was referred to as an ethylene copolymer (B-3). about The ethylene copolymers produced above are summarized in Table 2.

In Table 2,

*1: Type of ethylene copolymer of component B

*2: Type of monomer 1 that forms constituent unit 1

*3: The type of carboxylic acid monomer forming the constituent unit 2

*4: The type of monomer 3 that forms the constituent unit 3

Proportion: the unit is mass %

Monomers (e-1)~(e-4): monomers represented by formula (1) shown in Table 3 below

Monomer (f-1): Acrylic acid

Monomer (f-2): Methacrylic acid

Monomer (g-1): methyl acrylate

In Table 3,

EO: oxyethylene

PO: oxypropylene

EO(113)+PO(2): Addition of EO 113mol and PO 2mol totaling 115mol

Test category 3 (measurement of mass average molecular weight of components A and B)

The mass average molecular weights of A component and B component were measured by the following method. The results are shown in Tables 1 and 2.

Measurement of mass average molecular weight of component A

The mass average molecular weight of the polymer of acrylic acid and/or its salt in component A is carried out by gel permeation chromatography-multi-angle light scattering method (GPC-MALS method) and/or gel permeation chromatography method (GPC method) Measurements were performed under the following conditions. In addition, if the mass average molecular weight of polyacrylic acid exceeds 500,000, it cannot be measured by the GPC method, so the GPC-MALS method is used for the mass average molecular weight of polyacrylic acid exceeding 500,000. In addition, in A-3 and Ar-1, the difference between the molecular weights of the GPC-MALS method and the GPC method is within ±3%, and they are considered to be the same.

Measurement conditions

GPC-MALS method

Detectors: Differential Refractometer (RI), Multi-Angle Light Scattering Detector (MALS)

String: Showa Denko OHpak SB-807 HQ+SB-806M HQ

Eluent: 0.1M Tris buffer (pH=0.9, add 0.1M potassium chloride)/acetonitrile mixed solvent (mixing volume ratio: 7/3)

Flow rate: 0.5mL/min

Column temperature: 40°C

GPC method

Detector: differential refractometer (RI)

String: Showa Denko OHpak SB-G+SB-806M HQ+SB-806M HQ

Eluent: 50mM sodium nitrate aqueous solution

Flow rate: 0.7mL/min

Column temperature: 40°C

Standard substance: sodium polyacrylate manufactured by Agilent

Measurement of mass average molecular weight of component B

The mass average molecular weight of the ethylene copolymer of component B is measured by gel permeation chromatography (GPC method), and the conditions are as follows.

Measurement conditions

Detector: differential refractometer (RI)

String: Showa Denko OHpak SB-G+SB-806M HQ+SB-806M HQ

Eluent: 50mM sodium nitrate aqueous solution

Flow rate: 0.7mL/min

Column temperature: 40°C

Standard material: polyethylene glycol/oxide (PEG/PEO) manufactured by Agilent

Test category 4 (confirmation of compatibility)

Regarding the miscibility of the solution, when the ethylene copolymer of the B component was 20%, the ratio of the A component and the B component shown in Table 4 was fully stirred and mixed, and measured visually according to the following criteria. The concentration of the solution was adjusted using tap water.

Judgment criteria for miscibility

A: The degree of sedimentation or sedimentation cannot be discerned

B: Slight turbidity confirmed

C: Precipitation or settlement is confirmed

Test Category 5 (Preparation of Concrete Compositions as Hydraulic Compositions)

Under the blending conditions described in Table 5, concrete compositions were prepared in the following manner. Put ordinary portland cement (density 3.16g/cm ³ ) and fly ash (density 2.29g/cm ³ , loss on ignition 2.3% ), fine powder of blast furnace stone (density 2.88g/cm ³ ), and put in land sand from the Oigawa River system as fine aggregate (density 2.58g/cm ³ ) and crushed stone from Okazaki as coarse aggregate (density 2.68g/cm 3 ). cm ³ ), dry mixing was carried out for 10 seconds. After that, add a defoamer (manufactured by Takemoto Oil Co., Ltd.: Trade name AFK-2), the additive for the hydraulic composition used in the test category 4 was thrown in together with the mixing water, and kneaded for 90 seconds. In addition, additives and defoamers are considered part of the water.

The mixing of the blended materials and the following tests are carried out in an environment where the material temperature is set at 20±3°C, the room temperature is set at 20±3°C, and the humidity is set at 60% or more. For the concrete compositions prepared in each example, the slump fluidity immediately after mixing, the air volume immediately after mixing, the segregation resistance immediately after mixing, and the overflow after mixing were obtained in the following manner . A summary of the results is shown in Table 6.

Slump: for the concrete composition just after mixing, measure after lifting the slump cone for 3 minutes according to JIS-A1150.

Air volume: Measured in accordance with JIS-A1128 for the concrete composition immediately after mixing.

Segregation resistance: For the concrete composition just after mixing, after lifting the slump cone for 3 minutes, measure it visually according to the following criteria.

(Criteria for judging resistance to segregation)

A: Very good (aggregate and mortar, no separation of slurry)

B: Good (aggregate and mortar, slurry are slightly separated)

C: Poor (aggregate and mortar, slurry separation)

D: very poor (aggregate and mortar. Slurry is clearly separated)

Spillage: Measured in accordance with JIS-A1123 for the concrete composition immediately after mixing.

In Table 6,

*1: Total mass parts (solid content) of (A) component and (B) component with respect to 100 mass parts of adhesive

result

As shown in Table 6, compared with Comparative Example 6 containing only B component but not containing A component, Examples 10 to 18 containing A component and B component showed sufficient segregation resistance. It can also be seen that, compared with the comparative example, the overflow amount of each embodiment is also less. In addition, as shown in Table 4, additives ADR4 and ADR5, in which hydroxypropylmethylcellulose was blended instead of component A, had poor compatibility and no one-component property.

[industrial availability]

The additive for a hydraulic composition of the present invention can be used as an additive when preparing a hydraulic composition.

Claims (8)

An additive for a hydraulic composition, which contains the following component A and the following component B; component A: a polymer composed of acrylic acid and/or its salt, and its mass average molecular weight is not less than 100,000 and not more than 50,000,000; Component B: an ethylene copolymer having the following constituent unit 1 and constituent unit 2 in the molecule, and containing 1 to 99% by mass of constituent unit 1 and 1 to 99% by mass of constituent unit 2; constituent unit 1: composed of the following The structural unit formed by monomer 1; the structural unit 2: the structural unit formed by the carboxylic acid monomer 2 having a vinyl group in the molecule; the monomer 1: the unsaturated (poly)alkane shown in the following formula (1) alcohol:

In formula (1), R ¹ , R ² and R ³ are the same or different groups, and are selected from at least one of the organic groups represented by hydrogen atom, methyl group and -(CH ₂ )rCOOM, and wherein R ^1. At least one of R ² and R ³ represents a hydrogen atom or a methyl group, R ⁴ represents a hydrogen atom or a hydrocarbon group with 1 to 20 carbons, and R ⁵ O represents 1 of an oxyalkylene group with 2 to 4 carbons One or more kinds, p represents an integer from 0 to 5, q represents an integer from 0 or 1, m represents an integer from 1 to 300, r represents an integer from 0 to 2, and M represents a hydrogen atom or a metal atom. Such as the additive for hydraulic composition of claim 1, wherein, the B component is an ethylene copolymer further containing 0 to 30% by mass of the following structural unit 3; A structural unit formed by monomer 3 copolymerized with acid monomer 2. The additive for a hydraulic composition according to claim 1, wherein the mass % of the component A relative to the component B is 0.01 to 1 mass %. The additive for hydraulic compositions as claimed in item 1, wherein the mass average molecular weight of the component A is More than 500,000 and less than 1,000,000. For example, the additive for hydraulic compositions of claim 1, which is used for hydraulic compositions with a water-binder ratio of 35-65% and a slump fluidity of 35-70 cm. A hydraulic composition, which contains the additive for a hydraulic composition according to claim 1. As the hydraulic composition of claim 6, it further contains a binder. The hydraulic composition according to claim 7, wherein the total mass parts of the component A and the component B is 0.1 to 2 parts by mass relative to 100 parts by mass of the binder.