JP6749786B2 - Admixture for hydraulic composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to an admixture for a hydraulic composition and a hydraulic composition.

The dispersant for hydraulic composition is a chemical admixture used to disperse cement particles to reduce the amount of unit water required to obtain a required slump and improve workability of the hydraulic composition. Is.
As a dispersant for a hydraulic composition, conventionally, a naphthalene dispersant such as a naphthalene sulfonic acid formaldehyde condensate, a polycarboxylic acid dispersant such as a copolymer of a carboxylic acid and a monomer having an alkylene glycol chain. Melamine-based dispersants such as melamine sulfonic acid formaldehyde condensate are known.

On the other hand, attempts have been made to increase the viscosity of hydraulic compositions to improve the separation resistance of materials. Thickeners are used as one means to improve the viscosity of hydraulic compositions. Known examples of thickeners include cellulose derivatives such as methyl cellulose and hydroxyethyl cellulose, and synthetic polymers.

It has been proposed that a dispersant for a hydraulic composition and a thickener be prepared as a one-part formulation to obtain an admixture that can appropriately impart fluidity and viscosity to the hydraulic composition.
Patent Document 1 discloses an aqueous mixture of a specific vinyl polymer emulsion and a specific water-soluble vinyl copolymer, the liquidity of which shows a pH of 4 to 8 and the viscosity of which is generated by a hydration reaction of cement. Disclosed is a high-performance water-reducing agent composition comprising an aqueous mixture which is more than doubled in a pH range of 9 or more due to hydroxide.
Patent Document 2 discloses a weight average molecular weight obtained by copolymerizing a monomer composition containing a specific monomer (a1) having an oxyalkylene group and a specific monomer (a2) having a carboxyl group. Copolymer (1) of 10,000 to 500,000 and a monomer composition containing a polymerizable monomer (b1) having at least a carboxyl group, a (meth)acrylic acid ester and (b2) are used. Copolymer (2) having a weight average molecular weight of 100,000 to 10,000,000 obtained by polymerization (however, the weight average molecular weight of the copolymer (2) is larger than that of the copolymer (1)). And 99% by weight to 50% by weight of the copolymer (1) and 1% to 50% by weight of the copolymer (2) are disclosed.
In Patent Document 3, at least two or more kinds of (meth)acrylic acid alkyl ester-based monomers composed of methyl acrylate and other (meth)acrylic acid alkyl ester are the main components, and the amount of the methyl acrylate is Disclosed is a cement admixture containing a cement additive comprising a copolymer obtained by polymerizing a monomer component that is equal to or more than the amount of other (meth)acrylic acid alkyl ester. .. Patent Document 3 discloses that the cement admixture further contains a cement water reducing agent.

JP, 9-71447, A JP 2001-89212 A JP, 11-209155, A

However, when the polymer compound of the dispersant and the polymer compound of the thickener are made into an aqueous one-component type preparation, the storage stability tends to deteriorate. In the examples of Patent Document 1, it is shown that the viscosity of the high-performance water reducing agent composition does not change even after standing at 30° C. for 6 months. However, depending on the season or region, there is a possibility that the temperature may become higher or the temperature inside the storage tank may locally rise.
The present invention provides a one-pack type admixture for hydraulic composition, which can impart excellent fluidity and material separation resistance to the hydraulic composition and has more excellent storage stability.

The present invention relates to an admixture for a hydraulic composition containing the following component (A) and component (B).
Component (A): Alkali-thickening polymer (B) component: Consists of a monomer (1b) represented by the following general formula (1b) and a monomer (2b) represented by the following general formula (2b). A copolymer which is included as a monomer and in which the total amount of the monomer (1b) and the monomer (2b) in the constituent monomers is 90% by mass or more and 100% by mass or less.

[In the formula,
R ^1b and R ^2b : may be the same or different, and are a hydrogen atom or a methyl group R ^3b : hydrogen atom or —COO(AO) _n1 X ¹
X ¹ : a hydrogen atom or an alkyl group having 1 to 4 carbon atoms AO: a group selected from an ethyleneoxy group and a propyleneoxy group n1: an average addition mole number of AO, and a number of 100 or more and 300 or less q: 0 or more 2 The following numbers are shown. ]

[In the formula,
R ^4b , R ^5b , R ^6b : which may be the same or different, are a hydrogen atom, a methyl group or (CH ₂ ) _r COOM ² , and (CH ₂ ) _r COOM ² is COOM ¹ or another (CH ₂ ) It may form an anhydride with _r COOM ² , in which case M ¹ and M ² of those groups are absent.
M ¹ and M ^2, which may be the same or different, are a hydrogen atom, an alkali metal, an alkaline earth metal (1/2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group or Alkenyl group r: Indicates a number of 0 or more and 2 or less. ]

The present invention relates to a hydraulic composition containing the admixture for hydraulic composition of the present invention, hydraulic powder, and water.

The present invention also relates to the use of a mixture containing the component (A) and the component (B) as an admixture for a hydraulic composition.

According to the present invention, there is provided a one-pack type admixture for a hydraulic composition, which can impart excellent fluidity and material separation resistance to the hydraulic composition and has more excellent storage stability. The admixture for hydraulic compositions of the present invention has excellent long-term storage stability at high temperatures. In addition, the admixture for hydraulic composition of the present invention maintains the performance as an admixture even after being stored at high temperature.

[Admixture for hydraulic composition]
<(A) component>

The component (A) is an alkali thickening polymer.
The alkali-thickening type polymer has a property that when the polymer is contacted with an alkali, for example, an alkali of cement, it is neutralized and becomes soluble in water to increase the viscosity of a mixture containing the polymer and water. Say. For example, the alkali-thickening polymer may be a polymer in which a mixture containing the polymer and water having a pH of less than 9 thickens at a pH of 9 or more. Whether or not the polymer is of the alkali thickening type can be confirmed, for example, by the viscosity at pH 12.5 of the mixture containing the polymer and water being twice or more the viscosity at pH less than 9. The ratio of polymer to water in the mixture is arbitrary, and the temperature for measuring pH and viscosity can be selected as 20°C. The mixture may be an aqueous solution, an emulsion or a slurry. The method for measuring the viscosity may be the method described in Examples.

Examples of the alkali thickening polymer as the component (A) include copolymers containing an unsaturated compound (1a) containing an acidic group and an ethylenically unsaturated compound (2a) as constituent monomers. In this copolymer, the total amount of (1a) and (2a) in the constituent monomers is preferably 80% by mass or more, more preferably 90% by mass or more, and preferably 100% by mass or less. , May be 100% by mass.

Examples of the acidic group of the unsaturated compound (1a) containing an acidic group include a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, and a phenolic hydroxyl group. These may be salts.

Examples of the unsaturated compound (1a) containing an acidic group include unsaturated carboxylic acids (1a ₁ ).
As the unsaturated carboxylic acid (1a ₁ ),
Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, aconitic acid, and crotonic acid,
Unsaturated carboxylic acid anhydrides such as maleic anhydride and citraconic anhydride, and unsaturated carboxylic half esters such as monomethyl itaconate, monobutyl itaconate and monoethyl maleate,
And so on.

Further, as the unsaturated compound (1a) containing an acidic group,
Unsaturated sulfonic acids such as vinyl sulfonic acid, methallyl sulfonic acid, 2-(meth)acrylamido-2-methylpropane sulfonic acid,
Unsaturated phosphoric acid such as 2-((meth)acryloyloxy)ethyl phosphate and bis[2-((meth)acryloyloxy)ethyl hydrogen phosphate;
Unsaturated phenols such as vinylphenol,
And so on.

As the unsaturated compound (1a) containing an acidic group, an unsaturated carboxylic acid (1a ₁ ) is preferable. As the unsaturated carboxylic acid (1a ₁ ), a monomer (1a′) selected from acrylic acid and methacrylic acid is preferable, and methacrylic acid is more preferable.

Examples of the ethylenically unsaturated compound (2a) include (2a ₁ ) ethylene, cyanovinyl such as (2a ₂ ) acrylonitrile and methacrylonitrile, acrylic acid such as (2a ₃ ) methyl acrylate, ethyl acrylate, and butyl acrylate. Esters, methacrylic acid esters such as (2a ₄ ) methyl methacrylate, ethyl methacrylate, butyl methacrylate, hydroxyethyl methacrylate, and glycidyl methacrylate, (2a ₅ ) vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, Vinyl stearate, vinyl octylate, neodecanoic acid vinyl ester and other vinyl ester of aliphatic carboxylic acid having 3 to 18 carbon atoms, (2a ₆ ) methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, phenyl vinyl ether and other vinyl ether monomers, ( 2a ₇ ) polyfunctional vinyl monomers such as allyl methacrylate, (2a ₈ ) unsaturated hydrocarbons such as styrene and butadiene, and (2a ₉ ) acrylamide, methacrylamide, N-isopropylacrylamide, N-isopropylmethacrylamide, N And unsaturated amide compounds such as vinylpyrrolidone.
In addition, the compound containing an acidic group is excluded from the ethylenically unsaturated compound (2a). Therefore, the unsaturated compound (1a) containing an acidic group does not correspond to the ethylenically unsaturated compound (2a).

The ethylenically unsaturated compound (2a) is preferably a monomer (2a') selected from acrylic acid ester and methacrylic acid ester. The acrylic ester preferably has 1 to 8 carbon atoms in the ester portion. The methacrylic acid ester preferably has 1 to 4 carbon atoms in the ester portion. The monomer (2a') selected from acrylic acid ester and methacrylic acid ester is preferably one or more kinds of monomers selected from methyl acrylate, ethyl acrylate, methyl methacrylate and ethyl methacrylate.

The component (A) is preferably a copolymer containing an unsaturated carboxylic acid (1a ₁ ) and an ethylenically unsaturated compound (2a) as constituent monomers.
When the component (A) is a copolymer of the unsaturated carboxylic acid (1a ₁ ) and the ethylenically unsaturated compound (2a), the mass ratio of unsaturated carboxylic acid/ethylenically unsaturated compound is good From the viewpoint of obtaining viscosity, it is preferably 0.05 or more, more preferably 0.2 or more, even more preferably 0.4 or more, and preferably 20 or less, more preferably 5 or less, even more preferably 2. It is 5 or less. In this copolymer, the total amount of unsaturated carboxylic acid and ethylenically unsaturated compound in the constituent monomers is preferably 80% by mass or more, more preferably 90% by mass or more, and preferably 100% by mass or less. And may be 100% by mass.
Examples of the method for polymerizing the unsaturated carboxylic acid and the ethylenically unsaturated compound include emulsion polymerization, suspension polymerization, solution polymerization, bulk polymerization and the like.

The component (A) is a copolymer containing a monomer (1a′) selected from acrylic acid and methacrylic acid and a monomer (2a′) selected from acrylic acid ester and methacrylic acid ester as constituent monomers. A combination [hereinafter, referred to as a copolymer (A)] is more preferable.
Also in the copolymer (A), the monomer (2a′) is preferably one or more kinds of monomers selected from methyl acrylate, ethyl acrylate, methyl methacrylate and ethyl methacrylate.
From the viewpoint of material separation resistance of the hydraulic composition and storage stability of the admixture, the copolymer (A) is a monomer in the total of the monomer (1a′) and the monomer (2a′). The proportion of (1a′) is preferably 20% by mass or more, more preferably 30% by mass or more, further preferably 35% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, further preferably Is 55% by mass or less, more preferably 50% by mass or less, even more preferably 47% by mass or less, still more preferably 42% by mass or less.
In the copolymer (A), the total amount of the monomer (1a′) and the monomer (2a′) in the constituent monomers is preferably 60% by mass or more, more preferably 70% by mass or more, More preferably 80 mass% or more, even more preferably 85 mass% or more, even more preferably 90 mass% or more, even more preferably 95 mass% or more, and preferably 100 mass% or less, at 100 mass% It may be.

The component (A) preferably has a weight average molecular weight of 100,000 or more and 10,000,000 or less from the viewpoint of material separation resistance of the hydraulic composition and storage stability of the admixture. The weight average molecular weight of the component (A) is more preferably 150,000 or more, still more preferably 200,000 or more, even more preferably 250,000 or more, still more preferably 300,000 or more, still more preferably 500,000. And more preferably 8,000,000 or less, more preferably 5,000,000 or less, even more preferably 3,000,000 or less, still more preferably 2,000,000 or less, still more preferably Is 1,700,000 or less, more preferably 1,200,000 or less, still more preferably 700,000 or less.

The component (A) has a number average molecular weight of preferably 20,000 or more, more preferably 30,000 or more, and further preferably 35, from the viewpoint of material separation resistance of the hydraulic composition and storage stability of the admixture. ,000,000 or more, more preferably 40,000 or more, even more preferably 80,000 or more, and preferably 8,000,000 or less, more preferably 5,000,000 or less, even more preferably 2,000. 2,000 or less, more preferably 1,000,000 or less, still more preferably 500,000 or less, still more preferably 300,000 or less, still more preferably 250,000 or less, still more preferably 200,000 or less. , More preferably 180,000 or less, still more preferably 170,000 or less, still more preferably 165,000 or less, still more preferably 150,000 or less, still more preferably 100,000 or less.

The component (A) has a weight average molecular weight (Mw) to number average molecular weight (Mn) ratio of Mw/Mn of preferably 1 from the viewpoint of material separation resistance of the hydraulic composition and storage stability of the admixture. .1 or more, more preferably 2.0 or more, still more preferably 4.0 or more, still more preferably 5.0 or more, and preferably 10.0 or less, more preferably 8.0 or less, further preferably 7 or more. It is less than or equal to 0.0.

The weight average molecular weight and the number average molecular weight of the component (A) are measured by the gel permeation chromatography (GPC) method under the following conditions, respectively.
*GPC condition Device: GPC (HLC-8320GPC) Tosoh Corporation Column: TsKgelα-M+TsKgelα-M (Tosoh Corporation)
Eluent: 60 mmol/L phosphoric acid, 50 mmol/L LiBr-DMF
Flow rate: 1.0 mL/min
Column temperature: 40°C
Detection: RI
Sample size: 1 mg/mL
Standard substance: polystyrene conversion (monodisperse polystyrene with known molecular weight, molecular weight: 590, 3600, 30,000, 96400, 929000, 8420,000)

In the present invention, the component (A) is preferably the copolymer (A). In the present invention, the component (A) is more preferably the copolymer (A) having a weight average molecular weight within the above range.

The component (A) is available in the form of emulsion. An emulsion containing the component (A) may be used for preparing the admixture for a hydraulic composition of the present invention.

<(B) component>
The component (B) contains the monomer (1b) represented by the general formula (1b) and the monomer (2b) represented by the general formula (2b) as constituent monomers.
In formula (1b), R ^1b is preferably a hydrogen atom.
In general formula (1b), R ^2b is preferably a methyl group.
In general formula (1b), R ^3b is preferably a hydrogen atom.
In formula (1b), X ¹ is preferably a hydrogen atom or a methyl group, more preferably a methyl group.
In general formula (1b), AO is preferably an ethyleneoxy group. AO preferably contains an ethyleneoxy group.
In the general formula (1b), n1 is the average number of moles of AO added, and from the viewpoint of the storage stability of the admixture, 100 or more, preferably 110 or more, and 300 or less, preferably 250 or less, more preferably The number is 200 or less, more preferably 150 or less.
In general formula (1b), q is preferably 0.

In formula (2b), R ^4b is preferably a hydrogen atom.
In general formula (2b), R ^5b is preferably a methyl group.
In general formula (2b), R ^6b is preferably a hydrogen atom.
The _{(CH 2)} r COOM ^{2, COOM 1} or another _{(CH 2)} may form a r COOM ² and anhydride, in which case, ^M 1, ^{M 2} in these groups are not present.
M ¹ and M ² may be the same or different and each is a hydrogen atom, an alkali metal, an alkaline earth metal (1/2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group or It is an alkenyl group.
The alkyl group, hydroalkyl group, and alkenyl group of M ¹ and M ² each preferably have 1 to 4 carbon atoms.
M ¹ and M ² may be the same or different and are preferably a hydrogen atom, an alkali metal, an alkaline earth metal (1/2 atom), an ammonium group or an alkylammonium group, and a hydrogen atom, an alkali metal or an alkaline earth. A group metal (1/2 atom) or an ammonium group is more preferable, a hydrogen atom, an alkali metal or an alkaline earth metal (1/2 atom) is further preferable, and a hydrogen atom or an alkali metal is even more preferable.
Formula (2b) in the _{(CH ²⁾} r COOM ₂ r is 1 are preferred.

In the component (B), the total amount of the monomer (1b) and the monomer (2b) in the constituent monomers is 90% by mass or more, preferably 92% by mass or more, more preferably 95% by mass or more, And it is 100 mass% or less. This total amount may be 100% by weight.

In the component (B), the proportion of the monomer (2b) in the total of the monomer (1b) and the monomer (2b) is from the viewpoint of fluidity of the hydraulic composition and storage stability of the admixture. , Preferably 2% by mass or more, more preferably 4% by mass or more, further preferably 5% by mass or more, and preferably 50% by mass or less, more preferably 20% by mass or less, further preferably 15% by mass or less, It is more preferably 10% by mass or less.

The weight average molecular weight of the component (B) is preferably 20,000 or more, more preferably 30,000 or more, still more preferably 40,000 or more, from the viewpoint of fluidity of the hydraulic composition and storage stability of the admixture. , More preferably 50,000 or more, and preferably 100,000 or less, more preferably less than 100,000, further preferably 70,000 or less, still more preferably 60,000 or less.

The number average molecular weight of the component (B) is preferably 15,000 or more, more preferably 25,000 or more, further preferably 35,000 or more from the viewpoint of fluidity of the hydraulic composition and storage stability of the admixture. , And preferably 80,000 or less, more preferably 50,000 or less.

The component (B) has a weight average molecular weight (Mw) and number average molecular weight (Mn) ratio of Mw/Mn of preferably 1 from the viewpoint of material separation resistance of the hydraulic composition and storage stability of the admixture. 0.0 or more, more preferably 1.1 or more, further preferably 1.2 or more, and preferably 7.0 or less, more preferably 4.5 or less, still more preferably 2.0 or less.

The weight average molecular weight and the number average molecular weight of the component (B) are measured by the gel permeation chromatography (GPC) method under the following conditions, respectively.
*GPC conditions Device: GPC (HLC-8320GPC) Tosoh Corporation Column: G4000PWXL+G2500PWXL (Tosoh Corporation)
Eluent: 0.2 M phosphoric acid buffer _/ CH 3 CN = _9/1
Flow rate: 1.0 mL/min
Column temperature: 40°C
Detection: RI
Sample size: 0.2mg/mL
Standard substance: Polyethylene glycol equivalent (monodisperse polyethylene glycol with known molecular weight, molecular weight 87500, 250,000, 145,000, 46,000, 24,000)

<Composition, etc.>
The admixture for a hydraulic composition of the present invention preferably contains the component (A) in an amount of 0.5% by mass or more, and more preferably 1.0% by mass, from the viewpoint of material separation resistance and fluidity of the hydraulic composition. The above content is more preferably 1.5 mass% or more, and preferably 10.0 mass% or less, more preferably 8.0 mass% or less, still more preferably 5.0 mass% or less.

The admixture for a hydraulic composition of the present invention preferably contains the component (B) in an amount of 10% by mass or more, more preferably 15%, from the viewpoints of fluidity of the hydraulic composition, handleability of the admixture, and storage stability. It is contained in an amount of not less than 20% by mass, preferably not less than 20% by mass, more preferably not less than 23% by mass, further preferably not more than 40% by mass, more preferably not more than 35% by mass, further preferably not more than 30% by mass.

From the viewpoint of material separation resistance and fluidity of the hydraulic composition, the admixture for a hydraulic composition of the present invention preferably has a mass ratio of component (A)/component (B) of 0.01 or more, It is preferably 0.03 or more, more preferably 0.06 or more, and preferably 10 or less, more preferably 8 or less, still more preferably 6 or less.

The admixture for hydraulic compositions of the present invention preferably contains water. According to the present invention, an admixture for a hydraulic composition containing the component (A), the component (B) and water is provided. In the admixture for hydraulic composition of the present invention, the total content of the components (A) and (B) in the admixture is preferably 10% by mass or more, more preferably 15% by mass or more, and further preferably It is 20% by mass or more, and preferably 40% by mass or less, more preferably 35% by mass or less, and further preferably 30% by mass or less.

In the admixture for a hydraulic composition of the present invention containing the component (A), the component (B) and water, the pH at 20° C. is preferably 3.0 or more, more preferably 4.0 or more, and preferably Is 7.0 or less, and more preferably 6.5 or less.

In the admixture for a hydraulic composition of the present invention containing the component (A), the component (B) and water, the viscosity at 20° C. is preferably 10 mPa·s or more, more preferably from the viewpoint of handleability of the admixture. Is 20 mPa·s or more, and preferably 500 mPa·s or less, more preferably 300 mPa·s or less. Here, the viscosity of the admixture for hydraulic compositions can be measured by the method described in Examples.

The admixture for a hydraulic composition of the present invention includes, as optional components, an antifoaming agent, an antiseptic agent, a fast-setting component of a hydraulic composition, a curing accelerator, a curing retarder, an AE agent, a waterproofing agent, a shrinkage-reducing agent and A rusting agent, a crack reducing agent, a pH adjusting agent and other surfactants can be contained.

The application of the hydraulic composition to which the admixture for hydraulic composition of the present invention is applied is not limited, but mainly for high-fluidity concrete, underwater non-separable concrete, for sprayed concrete, concrete Examples include next products, concrete structures, and pump pumping improvement.

The present invention relates to the use of a mixture containing the component (A) and the component (B) as an admixture for a hydraulic composition. For this use, the matters described in the admixture for hydraulic composition of the present invention can be appropriately applied.

[Hydraulic composition]
The present invention relates to a hydraulic composition containing the admixture for hydraulic composition of the present invention, hydraulic powder, and water. That is, the present invention relates to a hydraulic composition containing the above-mentioned component (A), component (B), hydraulic powder, and water.
Specific examples of the admixture for hydraulic composition used in the hydraulic composition of the present invention and preferable examples of each component are the same as those of the admixture for hydraulic composition of the present invention.

Examples of hydraulic powders include ordinary Portland cement, early-strength cement, ultra-early-strength Portland cement, sulfate resistant Portland cement, low heat Portland cement, white cement, and ecocement (for example, JIS R 5214).
Further, the hydraulic powder may include powder having no hydraulic property. Examples of the powder having no hydraulic property include calcium carbonate, gypsum dihydrate, and the like. From the viewpoint of availability, calcium carbonate is preferred. In the hydraulic composition, the amount of the powder having no hydraulic property is preferably 0 kg/m ³ or more, more preferably 40 kg/m ³ or more, further preferably from the viewpoint of workability and cured physical properties of the hydraulic composition. It is 80 kg/m ³ or more, and preferably 600 kg/m ³ or less, more preferably 500 kg/m ³ or less, still more preferably 400 kg/m ³ or less.

Examples of the composition of the hydraulic composition include mortar and concrete. Of these, mortar and concrete using cement are preferable, and rich-mixed concrete with a large amount of cement is preferable in terms of excellent material separation resistance.

The W/P of the hydraulic composition is preferably 20% or more, more preferably 25% or more, and preferably 55% or less, more preferably 45, from the viewpoint of obtaining concrete having excellent separation resistance and high fluidity. % Or less. W/P is the mass percentage (mass %) of water and hydraulic powder in the slurry. When the hydraulic powder is cement, it may be abbreviated as W/C.

Applications of the hydraulic composition are not limited, but mainly include underwater concrete, sprayed concrete, secondary concrete products, and concrete structures.

<Synthesis example of component (A)>
Production Example A1 (Production of Copolymer A-1)
Into a glass reaction vessel (four-necked flask) equipped with a stirrer, 2 g of surfactant EMER 20C manufactured by Kao Co., Ltd. and 200 g of water were charged, nitrogen substitution was performed while stirring, and the temperature was raised to 70° C. in a nitrogen atmosphere. After the temperature in the system reached 70° C., an aqueous solution containing 0.61 g of ammonium persulfate and 5 g of ion-exchanged water was added. On the other hand, 40 g of acrylic acid, 30 g of ethyl acrylate, and 30 g of ethyl methacrylate were charged as monomers into the dropping funnel and added dropwise to the above reaction vessel at a constant rate over 3 hours. After the dropping was completed, the temperature was raised to 75° C., and the mixture was aged for 3 hours. After completion of aging, the mixture was cooled to 40° C. or lower to obtain a copolymer (A-1) having a weight average molecular weight of 1650,000. Then, the solid content was adjusted to 30% by mass with water to obtain an aqueous emulsion containing the copolymer A-1.
An aqueous emulsion of copolymer A-1 having a solid content of 1.0% by weight gave pH 2.7 and a viscosity of 4.5 mPa·s, while a 10% by weight aqueous sodium hydroxide solution gave a pH of 12.5 and a solid content of 1 Since the aqueous emulsion of the copolymer A-1 adjusted to 0.0% by mass gave a viscosity of 175.0 mPa·s, it was determined that the copolymer A-1 was an alkali thickening polymer. Both pH and viscosity are values at 20° C. (the same applies to the following production examples). The viscosity was measured with a B type viscometer (BM type VISCOMETER: manufactured by TOKIMEC INC., measurement condition: rotor No. 2, 60 rpm). The pH was measured with a pH meter (HM-30S: manufactured by Toa DKK).

Production Example A2 (Production of Copolymer A-2)
A copolymer was produced in the same manner as in Production Example A1 except that 50 g of acrylic acid and 50 g of ethyl acrylate were used as monomers, and the solid content was adjusted to 30% by mass with water to contain the copolymer A-2. An aqueous emulsion was obtained. The weight average molecular weight of the copolymer A-2 was 20,60,000.
An aqueous emulsion of copolymer A-2 having a solid content of 1.0% by weight gave pH 2.7 and a viscosity of 4.5 mPa·s, while a 10% by weight aqueous sodium hydroxide solution gave a pH of 12.5 and a solid content of 1 Since the aqueous emulsion of the copolymer A-2 adjusted to 0.0% by mass gave a viscosity of 165.0 mPa·s, it was determined that the copolymer A-2 was an alkali thickening polymer.

Production Example A3 (Production of Copolymer A-3)
A copolymer was produced in the same manner as in Production Example A1 except that 50 g of acrylic acid and 50 g of ethyl methacrylate were used as monomers, and the solid content was adjusted to 30% by mass with water to contain the copolymer A-3. An aqueous emulsion was obtained. The weight average molecular weight of the copolymer A-3 was 1,450,000.
An aqueous emulsion of copolymer A-3 having a solid content of 1.0% by mass gave pH 2.7 and a viscosity (20° C.) of 4.5 mPa·s, while a 10% by mass aqueous sodium hydroxide solution produced a pH of 12.5. Since the aqueous emulsion of the copolymer A-3 adjusted to have a solid content of 1.0% by mass gave a viscosity (20° C.) of 150.0 mPa·s, the copolymer A-3 was an alkali thickening polymer. I decided it was.

Production Example A4 (Production of Copolymer A-4)
A copolymer was produced in the same manner as in Production Example A1 except that the monomers were 50 g of methacrylic acid and 50 g of ethyl acrylate, and the solid content was adjusted to 30% by mass with water to contain the copolymer A-4. An aqueous emulsion was obtained. The weight average molecular weight of the copolymer A-4 was 1,600,000.
An aqueous emulsion of copolymer A-4 having a solid content of 1.0% by weight gave pH 2.7 and a viscosity of 4.5 mPa·s, while a 10% by weight aqueous sodium hydroxide solution gave a pH of 12.5 and a solid content of 1 Since the aqueous emulsion of the copolymer A-4 adjusted to 0.0% by mass gave a viscosity of 165.0 mPa·s, it was determined that the copolymer A-4 was an alkali thickening polymer.

Production Example A5 (Production of Copolymer A-5)
A copolymer was produced in the same manner as in Production Example A1 except that the monomers were 50 g of methacrylic acid and 50 g of ethyl methacrylate, and the solid content was adjusted to 30% by mass with water to contain the copolymer A-5. An aqueous emulsion was obtained. The weight average molecular weight of the copolymer A-5 was 19,50,000.
An aqueous emulsion of copolymer A-5 having a solid content of 1.0% by weight gave pH 2.7 and a viscosity of 4.5 mPa·s, while a 10% by weight aqueous sodium hydroxide solution gave a pH of 12.5 and a solid content of 1 Since the aqueous emulsion of the copolymer A-5 adjusted to 0.0% by mass gave a viscosity of 155.0 mPa·s, the copolymer A-5 was judged to be an alkali thickening polymer.

Production Example A6 (Production of Copolymer A-6)
A copolymer was produced in the same manner as in Production Example A1 except that the monomers were 45 g of methacrylic acid, 50 g of ethyl acrylate, and 5 g of stearoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 30), and were solidified using water. The content was adjusted to 30% by mass to obtain an aqueous emulsion containing the copolymer A-6. The weight average molecular weight of the copolymer A-6 was 2,160,000.
An aqueous emulsion of copolymer A-6 having a solid content of 1.0% by weight gave pH 2.7 and a viscosity of 4.5 mPa·s, while a 10% by weight aqueous sodium hydroxide solution gave a pH of 12.5 and a solid content of 1 Since the aqueous emulsion of the copolymer A-6 adjusted to 0.0% by mass gave a viscosity of 155.0 mPa·s, it was determined that the copolymer A-6 was an alkali thickening polymer.

<Synthesis Example of Component (B) and Comparative Copolymer>
Production Example B1 (Production of Copolymer B-1)
114 g of water was charged into a glass reaction vessel equipped with a stirrer (four-necked flask), the atmosphere was replaced with nitrogen while stirring, and the temperature was raised to 80° C. in a nitrogen atmosphere. 279 g of a 60% by weight aqueous solution of ω-methoxypolyethylene glycol monomethacrylate (average added mole number of ethylene oxide 120: ester purity 100% by weight), methacrylic acid (reagent: Wako Pure Chemical Industries, Ltd.) 24.1 g, and 3-mercapto. An aqueous solution in which 1.2 g of propionic acid was mixed and dissolved and an aqueous solution in which 1.9 g of ammonium persulfate was dissolved in 45 g of water were dropped into the above reaction vessel over 1.5 hours. Then, the mixture was aged at 80° C. for 1 hour, an aqueous solution of 0.8 g of ammonium persulfate dissolved in 15 g of water was added dropwise over 30 minutes, and subsequently aged at 80° C. for 1.5 hours. After the aging was completed, the mixture was cooled to 40°C or lower to obtain a copolymer (B-1) having a weight average molecular weight of 41,700. The mass ratio of ω-methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 120)/methacrylic acid was 87.4/12.6 [10/90 (molar ratio)]. Then, the solid content was adjusted to 40 mass% with water to obtain a 40 mass% aqueous solution of B-1. Copolymer B-1 was not an alkali thickening type.

Production Example B2 (Production of Copolymer B-2)
In Production Example B1, a copolymer was produced in the same manner as in Production Example B1 except that 300 g of a 60 mass% ω-methoxypolyethylene glycol monomethacrylate aqueous solution and 11.5 g of methacrylic acid were used. The mass ratio of ω-methoxypolyethylene glycol monomethacrylate (average added mole number of ethylene oxide: 120)/methacrylic acid was 94.0/6.0 [20/80 (molar ratio)]. After completion of aging and cooling, the solid content was adjusted to 40% by mass with water to obtain an aqueous solution containing the copolymer B-2. The weight average molecular weight of the copolymer B-2 was 55,000. Copolymer B-2 was not an alkali thickening type.

Production Example B3 (Production of Copolymer B'-1)
Except that ω-methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 23) and methacrylic acid were used as monomers at a mass ratio of 82.7/17.3 [27/73 (molar ratio)]. Produced a copolymer in the same manner as in Production Example B1. After completion of aging and cooling, the solid content was adjusted to 40% by mass with water to obtain an aqueous solution containing the copolymer B'-1. The weight average molecular weight of the copolymer B′-1 was 51,800.

Table 1 shows the copolymer of the component (A) obtained in the above production example. In addition, Table 2 shows the copolymers of the component (B) obtained in the above Production Examples and the comparative copolymers. In Table 2, components not corresponding to the component (B) are also shown in the column of the component (B) for convenience. The number average molecular weight (Mn) of each copolymer is also shown in Tables 1 and 2.

EO 30 mol of methacrylic acid stearyl: stearoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 30)

Methacrylic acid (methoxy polyethylene glycol 120 mol) ester: ω-methoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 120) [In the general formula (1b), R ^1b is a hydrogen atom, R ^2b is a methyl group, and R ^3b is hydrogen. Atom, X ¹ is a methyl group, AO is an ethyleneoxy group, n1 is 120 and q is 0]
Methacrylic acid (methoxypolyethylene glycol 23 mol) ester: ω-methoxypolyethylene glycol monomethacrylate (ethylene oxide average addition mole number 23) [Conveniently represented by the structure of the general formula (1b), R ^{1b in the} general formula (1b). Is a hydrogen atom, R ^2b is a methyl group, R ^3b is a hydrogen atom, X ¹ is a methyl group, AO is an ethyleneoxy group, n1 is 23, and q is 0]
B'-2: As the naphthalenesulfonic acid formalin condensate, Mighty 150 manufactured by Kao Corporation was used.

<Storage stability>
Component (A), component (B) and water were mixed in the proportions shown in Table 3, and the pH was adjusted to 5.5 with sodium hydroxide to obtain a one-pack type admixture for hydraulic composition. At the time of mixing, as the component (A), an aqueous emulsion having a solid content concentration of 30 mass% was used. In addition, during the mixing, as the component (B), an aqueous solution having a solid content concentration of 40 mass% was used.
The obtained admixture for hydraulic composition was placed in a 300 g container and stored at 40° C. for a predetermined period, and then the appearance of each was visually observed. The appearance was evaluated according to the following criteria. The results are shown in Table 3. In Table 3, the value of the comprehensive evaluation is the sum of the evaluation results of each period obtained by digitizing each evaluation as follows, and the larger the value, the higher the evaluation.
○: Homogeneous solution (2 points)
Δ: Slight precipitation on the bottom (1 point)
×: precipitation (0 points)

In Table 3, mass% is mass% in the hydraulic composition admixture (the balance is water). In Table 3, components that do not correspond to the component (B) are also shown in the column of the component (B) for convenience.

<Flowability and material separation resistance>
Using some of the admixtures for hydraulic compositions shown in Table 3, the fluidity and the material separation resistance to the concrete having the composition shown in Table 4 were evaluated. As the admixture for hydraulic composition, the one which was stored at 40° C. for 3 days after preparation was used. Since the admixture for hydraulic compositions of Comparative Example 1-1 caused precipitation, it was used by stirring and mixing uniformly. The results are shown in Table 5.

(1) Concrete Mixing Concrete was prepared using the following components in the amounts shown in Table 4.
Water: tap water cement: Ordinary portland cement, density 3.16 g / cm ³ (of the Pacific Ocean Cement Co. ordinary Portland cement and Sumitomo Osaka Cement Co., Ltd. ordinary Portland cement 1: 1 (mass ratio) mixture)
・Calcium carbonate: Neoflow 150, manufactured by Shimizu Industry Co., Ltd., density 2.71 g/cm ^3.
・Sand: Joyo sand, density 2.54 g/cm ³
・Gravel: Crushed stone from Iejima, density 2.63 g/cm ³

(2) Manufacture of concrete With the composition shown in Table 4, concrete was manufactured. After the gravel was introduced into the forced twin-screw mixer, sand, cement and calcium carbonate were introduced and stirring was started. Kneading water obtained by mixing the admixture for hydraulic composition and tap water was added at the same time when the mixer started stirring. 120 seconds after the start, concrete was discharged from the mixer. The hydraulic composition admixture was added in an amount of 0.8% by mass based on the amount of powder. The powder amount is the total amount of cement and calcium carbonate.

(2) Fluidity The slump flow value of concrete was measured according to JIS A 1150.

(3) Material Separation Resistance The concrete immediately after being discharged from the mixer was visually (visually) evaluated. The evaluation criteria are as follows.
○: Aggregate separation and water separation were not performed ×: Aggregate separation and water separation

Claims (12)

An admixture for a hydraulic composition containing the following component (A) and component (B).
Component (A): Alkali-thickening polymer (B) component: Consists of a monomer (1b) represented by the following general formula (1b) and a monomer (2b) represented by the following general formula (2b). A copolymer which is included as a monomer and in which the total amount of the monomer (1b) and the monomer (2b) in the constituent monomers is 90% by mass or more and 100% by mass or less.

[In the formula,
R ^1b and R ^2b : may be the same or different, and are a hydrogen atom or a methyl group R ^3b : hydrogen atom or —COO(AO) _n1 X ¹
X ¹ : a hydrogen atom or an alkyl group having 1 to 4 carbon atoms AO: a group selected from an ethyleneoxy group and a propyleneoxy group n1: an average number of moles of AO added, a number of 110 or more and 300 or less q: 0 or more 2 The following numbers are shown. ]

[In the formula,
R ^4b , R ^5b , R ^6b : which may be the same or different, are a hydrogen atom, a methyl group or (CH ₂ ) _r COOM ² , and (CH ₂ ) _r COOM ² is COOM ¹ or another (CH ₂ ) It may form an anhydride with _r COOM ² , in which case M ¹ and M ² of those groups are absent.
M ¹ and M ^2, which may be the same or different, are a hydrogen atom, an alkali metal, an alkaline earth metal (1/2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group or Alkenyl group r: Indicates a number of 0 or more and 2 or less. ] The admixture for hydraulic compositions according to claim 1, wherein the weight average molecular weight of the component (A) is 100,000 or more and 10,000,000 or less. The admixture for a hydraulic composition according to claim 1 or 2, wherein the component (B) has a weight average molecular weight of 20,000 or more and 100,000 or less. The ratio of the monomer (2b) to the total of the monomer (1b) and the monomer (2b) of the component (B) is 2% by mass or more and 50% by mass or less. An admixture for a hydraulic composition as described. The component (A) is a copolymer containing an unsaturated compound (1a) containing an acidic group and an ethylenically unsaturated compound (2a) as constituent monomers. Admixture for hydraulic composition. The hydraulic property according to any one of claims 1 to 5, wherein the component (A) is a copolymer containing an unsaturated carboxylic acid (1a1) and an ethylenically unsaturated compound (2a) as constituent monomers. Admixture for composition. Component (A) is a copolymer containing a monomer (1a') selected from acrylic acid and methacrylic acid and a monomer (2a') selected from acrylic acid ester and methacrylic acid ester as constituent monomers. The admixture for hydraulic compositions according to any one of claims 1 to 6, which is a united body. The hydraulic composition according to claim 7, wherein the monomer (2a′) is at least one monomer selected from the group consisting of methyl acrylate, ethyl acrylate, methyl methacrylate and ethyl methacrylate. Admixture. The admixture for hydraulic compositions according to any one of claims 1 to 8, which contains water. A hydraulic composition containing the admixture for hydraulic composition according to any one of claims 1 to 9, hydraulic powder, and water. Use of a mixture containing the following component (A) and component (B) as an admixture for a hydraulic composition.
Component (A): Alkali-thickening polymer (B) component: Consists of a monomer (1b) represented by the following general formula (1b) and a monomer (2b) represented by the following general formula (2b). A copolymer which is included as a monomer and in which the total amount of the monomer (1b) and the monomer (2b) in the constituent monomers is 90% by mass or more and 100% by mass or less.

[In the formula,
R ^1b and R ^2b : may be the same or different, and are a hydrogen atom or a methyl group R ^3b : hydrogen atom or —COO(AO) _n1 X ¹
X ¹ : a hydrogen atom or an alkyl group having 1 to 4 carbon atoms AO: a group selected from an ethyleneoxy group and a propyleneoxy group n1: an average number of moles of AO added, a number of 110 or more and 300 or less q: 0 or more 2 The following numbers are shown. ]

[In the formula,
R ^4b , R ^5b , R ^6b : which may be the same or different, are a hydrogen atom, a methyl group or (CH ₂ ) _r COOM ² , and (CH ₂ ) _r COOM ² is COOM ¹ or another (CH ₂ ) It may form an anhydride with _r COOM ² , in which case M ¹ and M ² of those groups are absent.
M ¹ and M ^2, which may be the same or different, are a hydrogen atom, an alkali metal, an alkaline earth metal (1/2 atom), an ammonium group, an alkylammonium group, a substituted alkylammonium group, an alkyl group, a hydroalkyl group or Alkenyl group r: Indicates a number of 0 or more and 2 or less. ] The use according to claim 11, wherein the component (A) is a copolymer containing an unsaturated compound having an acidic group and an ethylenically unsaturated compound as constituent monomers.