Dispersant composition for hydraulic composition and hydraulic composition

Abstract

To provide dispersant showing good kneadability improvement to a hydraulic composition.SOLUTION: A dispersant composition for hydraulic composition containing a component (A) and a component (B) which comprise specified copolymers being different from each other is provided. Also, a hydraulic composition containing a hydraulic powder, water, and the dispersant composition for hydraulic composition is provided.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a dispersant composition for a hydraulic composition and a hydraulic composition. [Background technology]

[0002] 2. Description of the Related Art Admixtures containing acrylic acid-based polyethylene glycol ethers for imparting fluidity to hydraulic compositions such as concrete are known.

[0003] For example, Patent Document 1 discloses a dispersant for a clay-containing hydraulic composition, which contains three types of acrylic acid copolymers and an acrylic acid copolymer to which ethylene oxide is added via an ether bond. Patent Document 2 discloses (A): an admixture for hydraulic compositions, which contains a polycarboxylic acid copolymer, (B) has a contact angle of 80° or less in an aqueous solution with a solid content of 30% as measured in accordance with JIS-R-3257, and (C) has a glass transition temperature (Tg) of 35°C or more. Furthermore, Patent Document 3 discloses an additive for hydraulic compositions, which contains a copolymer (A) which is a structural unit formed from a structural unit (1): polyethylene glycol isoprenyl ether, and a structural unit (2): an unsaturated carboxylic acid and / or a salt thereof, in which 80 to 100 mol % of the unsaturated carboxylic acid and / or a salt thereof is a structural unit formed from one or more selected from (meth)acrylic acid and / or a salt thereof, and which further has a structure derived from a hydrophobic chain transfer agent containing a sulfur atom, and has a mass average molecular weight of 100,000 or more and 2,000,000 or less in terms of polyethylene glycol as measured by gel permeation chromatography. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-18729 A [Patent Document 2] JP 2020-183341 A [Patent Document 3] WO2020 / 100211 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there has been no disclosure to date of improvements in the improvement of mixability when such a dispersant is used. [Means for solving the problem]

[0006] The present invention relates to a dispersant composition for a hydraulic composition comprising the following components (A) and (B): (A) Component: General formula (a1) [ka] [In the formula, R 1a represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. a represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. A structural unit (A1) represented by the formula: General formula (a2) [ka] [In the formula, R 2a represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X a represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. na represents the average number of moles added of 20 to 150. R 3a represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom.] A structural unit (A2) represented by the formula: and optionally the general formula (a3) [ka] [In the formula, R 4a R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 5a represents an alkyl group having 1 to 18 carbon atoms or a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom.] A copolymer having a structural unit (A3) represented by the following formula: Copolymer A, in which the proportion of the structural unit (A1) relative to the total of the structural units (A1), (A2), and (A3) is 3% by mass or more and less than 10% by mass. (B) Ingredients: General formula (b1) [ka] [In the formula, R 1b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. b represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. A structural unit (B1) represented by the formula: General formula (b2) [ka] [In the formula, R 2b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X b represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. nb represents the average number of moles added of 30 to 150. R 3b represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. A copolymer having a structural unit (B2) represented by the following formula: Copolymer B, in which the proportion of the structural unit (B1) relative to the total of the structural units (B1) and (B2) is 20% by mass or more and less than 35% by mass. Effect of the Invention

[0007] According to the present invention, it is possible to provide a dispersant composition for a hydraulic composition that can realize good improvement in mixing finish. Moreover, according to the present invention, a hydraulic composition containing the dispersant for hydraulic compositions can be provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] The dispersant composition for hydraulic compositions of the present invention contains the following components (A) and (B): (A) Component: General formula (A1) [ka] [In the formula, R 1a represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. a represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. A structural unit (A1) represented by the formula: General formula (A2) [ka] [In the formula, R 2a represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X a represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. na represents the average number of moles added of 20 to 150. R 3a represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom.] A structural unit (A2) represented by the formula: and optionally the general formula (a3) [ka] [In the formula, R 4a R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 5a represents an alkyl group having 1 to 18 carbon atoms or a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom.] A copolymer having a structural unit (A3) represented by the following formula: Copolymer A, in which the proportion of the structural unit (A1) relative to the total of the structural units (A1), (A2), and (A3) is 3% by mass or more and less than 10% by mass. (B) Ingredients: General formula (b1) [ka] [In the formula, R 1b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. b represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. A structural unit (B1) represented by the formula: General formula (b2) [ka] [In the formula, R 2b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X b represents a methylene group, an ethylene group, or a carbonyl group. nb represents the number of moles added of 30 or more and 150 or less. R 3b represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. A copolymer B having a structural unit (B2) represented by the following formula: Copolymer B, in which the proportion of the structural unit (B1) relative to the total of the structural units (B1) and (B2) is 20% by mass or more and less than 35% by mass.

[0009] First, the components (A) and (B) will be described. The component (A) is represented by the general formula (a1) [ka] [In the formula, R 1a represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. a represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. A structural unit (A1) represented by general formula (a2) [ka] [In the formula, R 2a represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X a represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. na represents the average number of moles added of 20 to 150. R 3a represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom.] and optionally a structural unit (A2) represented by general formula (a3) [ka] [In the formula, R 4a R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 5a represents an alkyl group having 1 to 18 carbon atoms or a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom.] Copolymer A has a structural unit (A3) represented by the following formula:

[0010] The structural unit (A1) represented by general formula (a1) can be introduced into the copolymer A by using a monomer represented by general formula (a1') as the raw material. [ka] [In the formula, R 1a represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. a represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium.

[0011] M in general formula (a1') aExamples of the cation include a hydrogen atom, alkali metals such as lithium, sodium, and potassium, and alkaline earth metals such as magnesium and calcium. In view of good dispersibility, a hydrogen atom or an alkali metal is preferred.

[0012] R in general formula (a1') 1a Examples of the alkyl group include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, etc. In terms of obtaining the copolymer in good yield, a hydrogen atom and a methyl group are preferred, and a hydrogen atom is more preferred.

[0013] The structural unit (A2) represented by general formula (a2) can be introduced into copolymer A by using a monomer represented by general formula (a2') as the raw material. [ka] [In the formula, R 2a represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X a represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. na represents an average number of moles added of 20 to 150. R 3a represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom.]

[0014] R in general formula (a2') 2a Specific examples of the alkyl group include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, etc. In terms of obtaining the copolymer in good yield, a hydrogen atom and a methyl group are preferred, and a hydrogen atom is more preferred.

[0015] X in general formula (a2') a Examples of the alkylene group include alkylene groups such as methylene, ethylene, propylene and butylene groups, and carbonyl groups. In view of good mortar flow performance, alkylene groups are preferred, and methylene and ethylene groups are more preferred.

[0016] In terms of good mortar flow performance, na in the general formula (a2') is preferably 20 or more, more preferably 40 or more, and even more preferably 50 or more, and is preferably 150 or less, more preferably 100 or less, and even more preferably 80 or less. In the present application, two or more monomers of the general formula (a2') may be used. When two or more monomers are used, the average number of moles added na is defined as the average number of moles added calculated according to the molar ratio thereof.

[0017] R in general formula (a2') 3a Specific examples of the alkyl group include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, a hexyl group, a 2-ethylhexyl group, a cyclohexyl group, an octyl group, a cyclooctyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, etc. In terms of good dispersibility, a hydrogen atom and a methyl group are preferred, and a hydrogen atom is more preferred.

[0018] The structural unit (A3) represented by general formula (a3) ​​can be introduced into copolymer A by using a monomer represented by general formula (a3') as the raw material. [ka] [In the formula, R 4a R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. 5a represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom.]

[0019] R in general formula (a3') 4a Specific examples of the alkyl group include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, etc. In terms of obtaining a copolymer in good yield, a hydrogen atom and a methyl group are preferred.

[0020] R in general formula (a3') 5aSpecific examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, hexyl, 2-ethylhexyl, cyclohexyl, octyl, cyclooctyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, etc. The methyl or 2-ethylhexyl group is preferred because of its good fluidity retention.

[0021] Even if the structural unit (A3) is not contained in the copolymer A, good mortar flow performance is sufficiently exhibited.

[0022] The proportion of the structural unit (A1) relative to the total of the structural units (A1), (A2), and (A3) is preferably 3 mass% or more, more preferably 4 mass% or more, and even more preferably 5 mass% or more, in terms of good mortar flow performance, and is preferably less than 10 mass%, more preferably less than 9 mass%.

[0023] The weight average molecular weight (Mw) of component (A) is preferably at least 10,000, more preferably at least 30,000, from the viewpoint of good shape retention and vibration resistance, and is preferably at most 80,000, more preferably at most 70,000. In addition, the ratio of Mw to number average molecular weight (Mn), Mw / Mn, is preferably at least 1.0 and not more than 2.0, from the viewpoint of good performance as a dispersant.

[0024] The (A) component can be produced under the conditions for copolymerization of general-purpose vinyl polymers. For example, water can be used as the solvent. The reaction temperature can be in the range of 50°C to 100°C. The reaction time depends on the reaction temperature, but can be in the range of 0.5 hours to 10 hours. The pH during production is preferably 3 or less.

[0025] The component (A) may be added as it is in the form of a copolymer, or may be added together with a suitable solvent (or dispersion medium). The solvent (or dispersion medium) is preferably water, and adding it together with water is preferred from the viewpoint of convenience. When adding it as a water solution (or dispersion), it is necessary to add the amount of water required for the composition of the present application, but this amount can be ignored when the concentration of the water solution (or dispersion) is high or the amount added is small.

[0026] Next, the component (B) will be described. The component (B) is represented by the general formula (b1) [ka] [In the formula, R 1b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. b represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. A structural unit (B1) represented by the formula: General formula (b2) [ka] [In the formula, R 2b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X b represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. nb represents the average number of moles added of 30 to 150. R 3b represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. Copolymer B has a structural unit (B2) represented by the following formula:

[0027] The structural unit (B1) represented by general formula (b1) can be introduced into copolymer B by using a monomer represented by general formula (b1') as the raw material. [ka] [In the formula, R 1brepresents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. a represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium.

[0028] M in general formula (b1') b Examples of the cation include a hydrogen atom, alkali metals such as lithium, sodium, and potassium, and alkaline earth metals such as magnesium and calcium. In view of good dispersibility, a hydrogen atom or an alkali metal is preferred.

[0029] R in general formula (b1') 1b Examples of the alkyl group include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, etc. In terms of good mortar flow performance, a hydrogen atom and a methyl group are preferred, and a methyl group is more preferred.

[0030] The structural unit (B2) represented by general formula (b2) can be introduced into copolymer B by using a monomer represented by general formula (b2') as the raw material. [ka] [In the formula, R 2b represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X b represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms. nb represents the average number of moles added of 30 to 150. R 3b represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.

[0031] R in general formula (b2') 2b Specific examples of the alkyl group include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, etc. In terms of obtaining the copolymer in good yield, a hydrogen atom and a methyl group are preferred, and a methyl group is more preferred.

[0032] X in general formula (b2') bExamples of the alkyl group include alkylene groups such as methylene, ethylene, propylene, and butylene, and carbonyl groups. The carbonyl group is preferred because it provides good mortar flow performance.

[0033] In terms of good mortar flow performance, nb in general formula (b2') is preferably 30 or more, more preferably 40 or more, even more preferably 50 or more, and is preferably 150 or less, more preferably 130 or less. In the present application, two or more monomers of general formula (b2') may be used. When two or more monomers are used, the average number of moles added nb is defined as the average number of moles added calculated according to the molar ratio thereof.

[0034] R in general formula (b2') 3b Specific examples of the alkyl group include a hydrogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a tert-butyl group, a hexyl group, a 2-ethylhexyl group, a cyclohexyl group, an octyl group, a cyclooctyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, etc. In terms of good dispersibility, a hydrogen atom and a methyl group are preferred, and a methyl group is more preferred.

[0035] The proportion of the structural unit (B1) relative to the total of the structural units (B1) and (B2) is preferably 20 mass% or more, more preferably 22 mass% or more, in terms of good mortar flow performance, and is preferably less than 35 mass%, more preferably less than 30 mass%, and even more preferably less than 25 mass%.

[0036] The weight average molecular weight (Mw) of component (B) is preferably 10,000 or more, more preferably 20,000 or more, in terms of good mortar flow performance, and is preferably 80,000 or less, more preferably 70,000 or less. In addition, the ratio of Mw to number average molecular weight (Mn), Mw / Mn, is preferably 1.0 or more and 2.0 or less, in terms of good performance as a dispersant.

[0037] The (B) component can be produced under the conditions for copolymerization of general-purpose vinyl polymers. For example, water can be used as the solvent. The reaction temperature can be in the range of 50°C to 100°C. The reaction time varies depending on the reaction temperature, but can be in the range of 0.5 hours to 10 hours. The pH during production is preferably 3 or less.

[0038] The amount of component (A) added is preferably 0.01 mass % or more, more preferably 0.05 mass % or more, based on the hydraulic powder in the hydraulic composition, in terms of good dispersibility of the hydraulic composition, and is preferably 1.0 mass % or less, more preferably 0.5 mass % or less, and even more preferably 0.3 mass % or less.

[0039] The amount of component (B) added is preferably 0.01 mass % or more, more preferably 0.05 mass % or more, based on the hydraulic powder in the hydraulic composition, in terms of good dispersibility of the hydraulic composition, and is preferably 1.0 mass % or less, more preferably 0.4 mass % or less, and even more preferably 0.2 mass % or less.

[0040] The component (B) may be added as it is in the form of a copolymer, or may be added together with a suitable solvent (or dispersion medium). The solvent (or dispersion medium) is preferably water, and adding it together with water is preferred from the viewpoint of convenience. When it is added as a water solution (or dispersion), it is necessary to add the amount of water required for the composition of the present application, but this amount can be ignored when the concentration of the water solution (or dispersion) is high or the amount added is small.

[0041] The mass ratio of component (A) to component (B), [component (A) / component (B)], is preferably 10 or less, more preferably 3 or less, even more preferably 2 or less, and is preferably 0.5 or more, more preferably 1 or more.

[0042] The hydraulic composition dispersant composition of the present invention may contain additives such as foaming agents, thickeners, foaming agents, preservatives, and antifoaming agents in addition to the components (A) and (B). These additives may be contained in an amount of 0.01% by mass or more and 2% by mass or less relative to the components (A) and (B). The antifoaming agents include one or more types of antifoaming agents selected from silicone-based antifoaming agents, fatty acid ester-based antifoaming agents, ether-based antifoaming agents, polyalkylene oxide-based antifoaming agents, alkyl phosphate ester-based antifoaming agents, and acetylene glycol-based antifoaming agents. The defoaming agent is preferably one or more defoaming agents selected from silicone-based defoaming agents, fatty acid ester-based defoaming agents, and ether-based defoaming agents.

[0043] The hydraulic powder used in the hydraulic composition of the present invention is a powder that hardens when mixed with water, and examples thereof include ordinary Portland cement, high-early-strength Portland cement, ultra-high-early-strength Portland cement, sulfate-resistant Portland cement, low-heat Portland cement, white Portland cement, and ecocement (e.g., JIS R5214, etc.). Among these, from the viewpoint of shortening the time required for the hydraulic composition to reach a required strength, a cement selected from early-early-strength Portland cement, ordinary Portland cement, sulfate-resistant Portland cement, and white Portland cement is preferred, and a cement selected from early-early-strength Portland cement and ordinary Portland cement is more preferred.

[0044] The water contained in the hydraulic composition of the present invention is preferably water that is free of impurities and is appropriately purified, but well water and industrial water may also be used. Tap water, purified water, and ion-exchanged water are preferred.

[0045] In addition, the ratio of water to the hydraulic powder in the hydraulic composition is preferably 5 mass% or more, more preferably 10 mass% or more, and preferably 45 mass% or less, more preferably 40 mass% or less, and even more preferably 35 mass% or less, from the viewpoints of strength expression and moldability of the hydraulic composition.

[0046] The dispersant of the present invention has a good mortar flow value and a funnel flow time, and therefore can be used as a dispersant for hydraulic compositions. In addition, a hydraulic composition containing the dispersant of the present invention and having a good mortar flow value and a funnel flow time can be provided. EXAMPLES

[0047] <Examples and Comparative Examples> The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to the following descriptions.

[0048] The materials used in the examples and comparative examples are shown below. <Component (A)> Copolymer A was produced using the following compounds as raw materials for the structural units (A1) and (A2). Raw materials for structural unit (A1): acrylic acid or methacrylic acid Raw material for structural unit (A2): 3-methyl-3-butenyl ether of polyethylene glycol represented by the following formula (1) (hereinafter referred to as TPEG66), [ka] 2-methyl-2-propenyl ether of polyethylene glycol (hereinafter referred to as HPEG) represented by the following formula (2): [ka] [wherein p is 55 (referred to as HPEG55) or 60 (referred to as HPEG60)] Or, methyl polyethylene glycol methacrylate ester (hereinafter referred to as MEPEG) represented by the following formula (3): [ka] [In the formula, nb represents 120 (referred to as MEPEG120)]

[0049] <Production of component (A) by copolymerization reaction> Taking the component (A) of Comparative Example 1 as an example, a method for producing the component (A) will be described below. 220.7 parts of TPEG66 and 141.3 parts of water were charged into a glass reaction vessel equipped with a stirrer, and the mixture was replaced with nitrogen while stirring, and the temperature was raised to 80°C in a nitrogen atmosphere. Then, 0.7 parts of hydrogen peroxide (35%) was added. An aqueous solution of 21.3 parts of acrylic acid dissolved in 31.9 parts and an aqueous solution of 1.2 parts of 3-mercaptopropionic acid dissolved in 38.0 parts of water were dropped into the vessel over 3.0 hours, and an aqueous solution of 0.3 parts of L-ascorbic acid dissolved in water was dropped into the vessel over 3.5 hours. Then, the mixture was aged at the same temperature (80°C) for 1 hour. After the aging, the mixture was neutralized with 12.3 parts of 48% aqueous sodium hydroxide solution to obtain an aqueous solution containing a copolymer (A) having a weight average molecular weight of 56,000. A reaction product containing and water was obtained.

[0050] <(B) component> Copolymer B was produced using the following compounds as raw materials for the structural units (B1) and (B2). Raw material for structural unit (B1): methacrylic acid Raw material for structural unit (B2): MEPEG represented by the following formula (3) [ka] [In the formula, nb represents 23 (referred to as MEPEG23), 60 (referred to as MEPEG60), or 120 (referred to as MEPEG120).] MEPEG60 was obtained by mixing MEPEG120 (nb is 120) and MEPEG23 (nb is 23) in a molar ratio of 3.6 / 5.9. The nb of the resulting mixture was calculated from the nb value and molar fraction of each component using the following formula. 120×(3.6 / 9.5)+23×(5.9 / 9.5)=60

[0051] <Production of component (B) by copolymerization reaction> Taking the component (B) of Comparative Example 4 as an example, a method for producing the component (B) will be described below. 432.42 parts of water was charged into a glass reaction vessel equipped with a stirrer, and the mixture was replaced with nitrogen while stirring, and the temperature was raised to 80°C in a nitrogen atmosphere. (i) A solution obtained by mixing and dissolving 447.95 parts of an aqueous solution containing methacrylic acid and MEPEG120 ester (water content 39.15% by mass, methacrylic acid content 2.97% by mass, MEPEG120 ester content 51.37% by mass), 56.27 parts of methacrylic acid, and 6.98 parts of 2-mercaptoethanol, and (ii) an aqueous solution obtained by dissolving 4.85 parts of ammonium persulfate in 19.40 parts of water, were each dropped into the vessel over 1.5 hours. Next, an aqueous solution obtained by dissolving 3.88 parts of ammonium persulfate in 15.52 parts of water was dropped over 30 minutes, and then the mixture was aged at the same temperature (80°C) for 1 hour. After the aging was completed, the mixture was neutralized with 9.86 parts of a 48% aqueous sodium hydroxide solution to obtain a water-containing (B) component.

[0052] Table 1 shows the hydraulic composition dispersant compositions produced in the Examples and Comparative Examples, and the mass ratio of the (A) component to the (B) component cement. [Table 1]

[0053] <Other materials> Cement: Ordinary Portland cement manufactured by Taiheiyo Cement Corporation and Sumitomo Osaka A 1:1 mixture of ordinary Portland cement (density 3.16 g / cm3) manufactured by Cement Co., Ltd. 3 ) Fine aggregate: mountain sand, density 2.72g / cm 3

[0054] <Production of hydraulic composition> 400 parts by weight of cement and 700 parts by weight of fine aggregate were added to a mortar mixer specified in JIS R5201, and dry mixing (60 rpm, 10 seconds) was performed. Thereafter, water containing component (A) or component (B) was added so as to obtain the content shown in Table 1, and the mixture was kneaded (60 rpm, 120 seconds) to prepare the hydraulic composition shown in Table 2.

[0055] Using the hydraulic composition dispersant compositions of each of the Examples and Comparative Examples in Table 2, evaluations were performed on mortar flow, funnel flow time, and viscosity over time.

[0056] <Evaluation of mortar flow> The hydraulic compositions immediately after mixing and 20 minutes after mixing were filled into a flow cone (upper diameter 70 mm x lower diameter 100 mm x height 60 mm) according to JIS R 5201, and the flow was measured on a 30 cm x 30 cm plastic plate.

[0057] <Evaluation of funnel flow time> The hydraulic composition immediately after mixing and 20 minutes after mixing were measured using a hydraulic composition flow time measuring device consisting of a 300 mm long cylinder with a tapered shape having an upper inlet opening with an opening diameter of 100 mm and a lower outlet opening with an opening diameter of 20 mm. The outlet part was blocked with a rubber plug, the hydraulic composition sample was filled up to the surface of the inlet opening (a fixed amount), the rubber plug of the outlet part was removed, and the time until all of the hydraulic composition was discharged was measured (see Examples 1 to 6 of JP 2001-215185 A).

[0058] <Evaluation of viscosity over time> The time taken for the mixture to flow through the funnel after 20 minutes of kneading was divided by the time taken for the mixture to flow through the funnel immediately after kneading (percentage %), and this was taken as the viscosity over time.

[0059] The results are shown in Table 2. [Table 2]

[0060] In Examples 1 to 4, the mortar flow was good, being 199 to 210 mm immediately after mixing and 293 to 320 mm after 20 minutes of mixing. The funnel flow time was 12.1 to 12.6 seconds immediately after mixing and 10.3 to 11.3 seconds after 20 minutes of mixing, and the viscosity over time was calculated to be 85 to 91%. In Comparative Example 1, which did not contain component (B) and had a large na value of component (A) (120), the mortar flow was larger than in the Examples. In Comparative Example 2, even though na was set to 66, the funnel flow time after 20 minutes of kneading was longer than in the Examples, since component (B) was not contained. In Comparative Example 3, which did not contain component (A), the mortar flow value was large, and the mixture did not flow down the funnel after 20 minutes of kneading. In Comparative Example 4, which contained a large amount of (A1) in component (A), the funnel flow time after 20 minutes of kneading was long at 23.5 seconds, and in Comparative Example 5, which had a small nb of component (B), the mortar flow after 20 minutes of kneading was large.

[0061] In this way, by optimizing the composition ratio of the (A) component and the (B) component and na and nb, a dispersant composition having a good mortar flow value and funnel flow time could be obtained.

Claims

1. A dispersant composition for hydraulic compositions comprising the following components (A) and (B): Component (A): General formula (a1) 【Chemical 1】 [In the formula, R １ａ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ａ represents a hydrogen atom, an alkali metal, an alkaline earth metal (half an atom), ammonium, or an organic ammonium. A structural unit (A1) represented by the formula: General formula (a2) 【Chemistry 2】 [In the formula, R ２ａ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ａ represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms; and na represents the average number of moles added of 20 to 150. ３ａ represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, or a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom. A structural unit (A2) represented by the formula: and optionally a compound of general formula (a3) 【Chemistry 3】 [In the formula, R ４ａ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ５ａ represents an alkyl group having 1 to 18 carbon atoms or a hydrocarbon group having 1 to 4 carbon atoms which may contain a heteroatom. A copolymer having a structural unit (A3) represented by the following formula: Copolymer A, in which the proportion of the structural unit (A1) relative to the total of the structural units (A1), (A2), and (A3) is 3% by mass or more and less than 10% by mass. (B) Component: General formula (b1) 【Chemistry 4】 [In the formula, R １ｂ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ｂ represents a hydrogen atom, an alkali metal, an alkaline earth metal (half an atom), ammonium, or an organic ammonium. A structural unit (B1) represented by the formula: General formula (b2) 【Chemistry 5】 [In the formula, R ２ｂ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ｂ represents an alkylene group or a carbonyl group having 1 to 4 carbon atoms; nb represents the average number of moles added of 30 to 150. ３ｂ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. A copolymer having a structural unit (B2) represented by the following formula: Copolymer B, in which the proportion of the structural unit (B1) relative to the total of the structural units (B1) and (B2) is 20% by mass or more and less than 35% by mass.

2. X in general formula (a2) ａ The dispersant composition for hydraulic compositions according to claim 1, wherein is an alkylene group having 1 to 4 carbon atoms.

3. X in general formula (b2) ｂ The dispersant composition for hydraulic compositions according to claim 1, wherein is a carbonyl group.

4. 2. The dispersant composition for hydraulic compositions according to claim 1, wherein nb of the structural unit (B2) is 30 or more and 130 or less.

5. The dispersant composition for hydraulic compositions according to claim 1 , which does not contain the structural unit (A3).

6. 2. The dispersant composition for hydraulic compositions according to claim 1, wherein the weight average molecular weight of component (A) is 10,000 or more and 80,000 or less.

7. 2. The dispersant composition for hydraulic compositions according to claim 1, wherein the weight average molecular weight of component (B) is 10,000 or more and 80,000 or less.

8. A hydraulic composition comprising a hydraulic powder containing cement, water, and the dispersant composition for hydraulic compositions according to any one of claims 1 to 7.

9. 9. The hydraulic composition according to claim 8, wherein the ratio of water to hydraulic powder is 5% by mass or more and 45% by mass or less.

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