Dispersant for hydraulic composition for spraying

Abstract

This dispersant for a hydraulic composition for spraying contains a copolymer (A) having: a constitutional unit (I) derived from a monomer represented by general formula (A1); and a constitutional unit (II) derived from a monomer represented by general formula (A2).

Description

Dispersant for sprayed hydraulic composition

[0001] The present invention relates to a dispersant for a sprayed hydraulic composition, a sprayed hydraulic composition, a method for producing a sprayed hydraulic composition, a spraying method, and use as a dispersant for a sprayed hydraulic composition.

[0002] Background Art In order to prevent the collapse of exposed natural ground such as tunnel excavation, a spraying method using quick-setting concrete or quick-setting mortar containing a quick-setting agent in concrete has been performed. In this method, sprayed concrete is usually prepared at a weighing and mixing plant for cement, aggregate, and water installed at the excavation site, and then transported by an agitator truck and transferred to a spraying machine. Then, the sprayed concrete and the quick-setting agent are joined and mixed by a line that pneumatically transports the sprayed concrete to the discharge port by a pump of the spraying machine and a line that pneumatically transports the quick-setting agent from the other side through a joining pipe provided in the middle, and it is a method of spraying the quick-setting sprayed concrete onto the natural ground surface until it reaches a specific thickness.

[0003] Japanese Patent Laid-Open No. 11-349369 discloses high-strength fresh concrete having a water / cement ratio containing cement, fine aggregate, coarse aggregate, a cement dispersant, and water, using a specific cement as the cement and a specific cement dispersant as the cement dispersant, and containing a specific cement dispersant in a predetermined ratio with respect to such a specific cement, and using it in a wet spraying concrete method. Further, Japanese Patent Laid-Open No. 2021-75436 discloses an adhesion reducing agent for a pipe for a sprayed hydraulic composition containing (A) a polymer having a weight average molecular weight of 20,000 or more and 6,500,000 or less containing a monomer selected from acrylic acid or its salt, an acrylic acid ester, methacrylic acid or its salt, a methacrylic acid ester, and acrylamide, and (B) a quick-setting agent.

[0004] Summary of the Invention In sprayable hydraulic compositions, polycarboxylic acid-based dispersants are used from the viewpoint of workability and pumpability. However, while polycarboxylic acid-based dispersants make sprayable hydraulic compositions flow easily, they tend to have difficulty in developing strength and relatively poor moldability (the shape collapses even after molding) compared to other dispersants. On the other hand, when trying to ensure the strength development and moldability of sprayable hydraulic compositions, there is a problem of reduced workability such as nozzle clogging due to decreased fluidity of the sprayable hydraulic composition. The present invention provides a dispersant for sprayable hydraulic compositions that is excellent in moldability and strength development and suppresses nozzle clogging, a sprayable hydraulic composition, a method for manufacturing a sprayable hydraulic composition, a spraying method, and use as a dispersant for sprayable hydraulic compositions.

[0005] In one embodiment, the present invention provides a dispersant for sprayable hydraulic compositions, which contains (A) a copolymer (A) having a monomer-derived constituent unit (I) represented by the following general formula (A1) and a monomer-derived constituent unit (II) represented by the following general formula (A2).

[0006]

[0007] [In the formula, R １ａ This represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ This represents a hydrogen atom, alkali metal, alkaline earth metal (half atom), ammonium, or organic ammonium.

[0008]

[0009] [In the formula, R ２ａ X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ represents an alkylene group or carbonyl group having 1 to 4 carbon atoms. AO represents an alkylene oxy group having 2 or 3 carbon atoms. n1 is the average number of moles of AO added, and is a number of 100 or more. R ３ａ This represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.

[0010] Furthermore, in another embodiment, the present invention provides a sprayable hydraulic composition containing the dispersant for sprayable hydraulic compositions.

[0011] Furthermore, in another embodiment, the present invention provides a method for producing a sprayable hydraulic composition, comprising mixing the dispersant for sprayable hydraulic compositions with hydraulic powder.

[0012] Furthermore, in another embodiment, the present invention provides a spraying method in which a hydraulic composition containing hydraulic powder and water is mixed with a dispersant for the sprayed hydraulic composition and sprayed onto an object.

[0013] Furthermore, in another embodiment, the present invention provides the use of the copolymer (A) as a dispersant for sprayable hydraulic compositions.

[0014] The present invention provides a dispersant for sprayable hydraulic compositions that exhibits excellent moldability and strength development, and suppresses nozzle clogging; a sprayable hydraulic composition; a method for producing a sprayable hydraulic composition; a spraying method; and the use of the dispersant for sprayable hydraulic compositions.

[0015] Modes for Carrying Out the Invention The mechanism by which a sprayable hydraulic composition containing the dispersant for sprayable hydraulic compositions of the present invention exhibits excellent moldability and strength development, and suppresses nozzle clogging, is not clear, but is presumed to be as follows: The copolymer (A) has constituent units (II) having polyoxyalkylene chains with an average number of added moles of 100 moles or more that exhibit strong steric repulsion, thereby providing strong steric repulsion and strong dispersibility, and it is presumed that the sprayable hydraulic composition before spraying becomes easier to atomize and discharge. Furthermore, when the sprayable hydraulic composition is atomized, it can be strongly compacted during spraying, which is presumed to improve the strength development and shape retention of the sprayable hydraulic composition. It should be noted that the use of the dispersant for sprayable hydraulic compositions, sprayable hydraulic compositions, methods for producing sprayable hydraulic compositions, spraying methods, and dispersants for sprayable hydraulic compositions of the present invention is not limited to the above mechanism.

[0016] <Dispersant for Spraying Hydraulic Composition> In an exemplary embodiment, the dispersant for spraying hydraulic composition of the present invention contains a copolymer (A) having a structural unit (I) derived from a monomer represented by the following general formula (A1) [hereinafter also referred to as structural unit (I)], and a structural unit (II) derived from a monomer represented by the following general formula (A2) [hereinafter also referred to as structural unit (II)].

[0017]

[0018] [In the formula, R １ａ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. M １ represents a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. ]

[0019]

[0020] [In the formula, R ２ａ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. X １ represents an alkylene group having 1 to 4 carbon atoms or a carbonyl group. AO represents an alkyleneoxy group having 2 or 3 carbon atoms. n1 is the average number of moles of AO added, and represents a number of 100 or more. R ３ａ represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. ]

[0021] <Copolymer (A)> The copolymer (A) contains, as structural units, a structural unit (I) derived from a monomer represented by the general formula (A1) and a structural unit (II) derived from a monomer represented by the general formula (A2).

[0022] In the general formula (A1), R １ａ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and from the viewpoints of the moldability, strength development property of the hydraulic composition and suppression of nozzle clogging, a hydrogen atom or a methyl group is preferable, and a methyl group is more preferable. In the general formula (A1), M １ includes a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2 atom), ammonium, or an organic ammonium. M １The preferred material is an alkali metal, ammonium, or organic ammonium. Examples of alkali metals include sodium and potassium. Examples of organic ammonium include alkanolammonium.

[0023] In general formula (A2), R ２ａ R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, a hydrogen atom or a methyl group is preferred, and a methyl group is more preferred. In general formula (A2), R ３ａ X represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. From the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, an alkyl group having 1 to 18 carbon atoms is preferred, and a propyl group, ethyl group, or methyl group is more preferred. In general formula (A2), X １ is an alkylene group having 1 to 4 carbon atoms, or a carbonyl group (CO group), with a carbonyl group (CO group) being preferred. In general formula (A2), AO represents an alkylene oxy group having 2 or 3 carbon atoms, and an ethylene oxy group is preferred from the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition. When AO contains an ethylene oxy group and a propylene oxy group, the ethylene oxy group and the propylene oxy group may be block-bonded or randomly bonded. In general formula (A2), n1 represents the average number of moles added of AO groups, and from the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition, it is a number of 100 or more, preferably 105 or more, more preferably 110 or more, and preferably 200 or less, more preferably 150 or less, and even more preferably 130 or less. Alternatively, in general formula (A2), n1 is preferably a number between 100 and 200, more preferably between 105 and 150, and even more preferably between 110 and 130, from the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition.

[0024] In copolymer (A), the molar ratio of constituent unit (I) to constituent unit (II) [(I) / (II)] is preferably 0.5 or more, more preferably 1.0 or more, and even more preferably 1.5 or more, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, and preferably 30 or less, more preferably 25 or less, and even more preferably 20 or less. Alternatively, in copolymer (A), the molar ratio of constituent unit (I) to constituent unit (II) [(I) / (II)] is preferably 0.5 or more and 30 or less, more preferably 1.0 or more and 25 or less, and even more preferably 1.5 or more and 20 or less, from the same viewpoint. In this invention, the amount of constituent units in copolymer (A) may be calculated based on the amount of monomer used in the synthesis of copolymer (A).

[0025] From the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, the copolymer (A) has a ratio of constituent unit (II) to the total of constituent unit (I) [(II) / [(I)+(II)]] which is preferably 1% by mass or more, more preferably 2% by mass or more, and preferably 30% by mass or less, and more preferably 26% by mass or less. Alternatively, from the same viewpoint, the copolymer (A) has a ratio of constituent unit (II) to the total of constituent unit (I) [(II) / [(I)+(II)]] which is preferably 1% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 26% by mass or less.

[0026] Furthermore, the copolymer (A) has a total proportion of constituent units (I) and (II) in all constituent units that is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less, and may be 100% by mass, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition. Alternatively, the copolymer (A) has a total proportion of constituent units (I) and (II) in all constituent units that is preferably 80% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less, and even more preferably 95% by mass or more and 100% by mass or less, from the same viewpoint.

[0027] From the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, copolymer (A) preferably has a weight-average molecular weight (Mw) of 5,000 or more, more preferably 10,000 or more, even more preferably 20,000 or more, and preferably 200,000 or less, more preferably 150,000 or less, and even more preferably 100,000 or less. Alternatively, from the same viewpoint, copolymer (A) preferably has a weight-average molecular weight (Mw) of 5,000 or more and 200,000 or less, more preferably 10,000 or more and 150,000 or less, and even more preferably 20,000 or more and 100,000 or less. The weight-average molecular weight of copolymer (A) was measured by GPC under the following conditions: high-speed GPC instrument (HLC-8320GPC, Tosoh Corporation), detector: RI, column: G4000PWXL + G2500PWXL (anion), mobile phase: 0.2 M phosphate buffer / acetonitrile = 9 / 1, flow rate: 1.0 mL / min, column temperature: 40°C, standard substance: polyethylene glycol.

[0028] From the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition, copolymer (A) preferably has a proportion of compounds with a molecular weight of 8,000 or less (hereinafter also referred to as the low molecular weight ratio) of 5.0% by mass or more, more preferably 6.0% by mass or more, and preferably 15.0% by mass or less, and more preferably 14.0% by mass or less. Alternatively, from the same viewpoint, copolymer (A) preferably has a low molecular weight ratio of 5.0% by mass or more and 15.0% by mass or less, and more preferably 6.0% by mass or more and 14.0% by mass or less. The low molecular weight ratio of copolymer (A) is calculated by the ratio of peak areas using the GPC method described above.

[0029] From the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, copolymer (A) preferably has a number average molecular weight (Mn) of 5,000 or more, more preferably 7,000 or more, even more preferably 8,500 or more, and preferably 200,000 or less, more preferably 100,000 or less, and even more preferably 40,000 or less. Alternatively, from the same viewpoint, copolymer (A) preferably has a number average molecular weight (Mn) of 5,000 or more and 200,000 or less, more preferably 7,000 or more and 100,000 or less, and even more preferably 8,500 or more and 40,000 or less. The number-average molecular weight (Mn) of copolymer (A) was measured by GPC under the following conditions: high-speed GPC instrument (HLC-8320GPC, Tosoh Corporation), detector: RI, column: G4000PWXL + G2500PWXL (anion), mobile phase: 0.2 M phosphate buffer / acetonitrile = 9 / 1, flow rate: 1.0 mL / min., column temperature: 40°C, standard substance: polyethylene glycol.

[0030] The polydispersity (Mw / Mn) of copolymer (A) is preferably 1.02 or higher, more preferably 2.0 or higher, even more preferably 2.5 or higher, and from the same viewpoint, preferably 10 or lower, more preferably 8 or lower, and even more preferably 6 or lower. Alternatively, the polydispersity (Mw / Mn) of copolymer (A) is preferably 1.02 or higher and 10 or lower, more preferably 2.0 or higher and 8 or lower, and even more preferably 2.5 or higher and 6 or lower, from the same viewpoint. The polydispersity (Mw / Mn) of copolymer (A) is calculated as the ratio (Mw / Mn) of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn) of copolymer (A).

[0031] The copolymer (A) may be a copolymer that optionally contains constituent units (III) derived from monomers represented by the following general formula (A3) [hereinafter also referred to as constituent units (III)].

[0032]

[0033] [In the formula, R ４ａ X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ２represents an alkylene group or carbonyl group having 1 to 4 carbon atoms. AO represents an alkylene oxy group having 2 or 3 carbon atoms. n2 is the average number of moles of AO added, and represents a number between 5 and 100. R ５ａ This represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0034] In general formula (A3), R ４ａ R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, a hydrogen atom or a methyl group is preferred, and a methyl group is more preferred. In general formula (A3), R ５ａ X represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. From the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, an alkyl group having 1 to 2 carbon atoms is preferred, and a methyl group is more preferred. In general formula (A3), X ２ is an alkylene group having 1 to 4 carbon atoms, or a carbonyl group (CO group), with a carbonyl group (CO group) being preferred. In general formula (A3), AO represents an alkylene oxy group having 2 to 3 carbon atoms, and an ethylene oxy group is preferred from the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition. When AO contains an ethylene oxy group and a propylene oxy group, the ethylene oxy group and the propylene oxy group may be block-bonded or randomly bonded. In general formula (A3), n2 represents the average number of moles added of AO groups, and from the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition, it is a number of 5 or more, preferably 9 or more, more preferably 20 or more, and less than 100, preferably 90 or less, more preferably 80 or less, and even more preferably 70 or less. Alternatively, from the same viewpoint, n2 is a number of 5 or more and less than 100, preferably 5 or more and 90 or less, more preferably 9 or more and 80 or less, and even more preferably 20 or more and 70 or less.

[0035] When copolymer (A) has constituent unit (III), the molar ratio of constituent unit (II) to constituent unit (III) [(II) / (III)] in copolymer (A) is preferably 0.05 or more, more preferably 0.10 or more, even more preferably 0.16 or more, and from the same viewpoint, preferably 100 or less, more preferably 90 or less, and even more preferably 80 or less. Alternatively, when copolymer (A) has constituent unit (III), the molar ratio [(II) / (III)] is preferably 0.05 or more and 100 or less, more preferably 0.10 or more and 90 or less, and even more preferably 0.16 or more and 80 or less.

[0036] In copolymer (A), the average number of moles of AO added to constituent unit (II) and constituent unit (III) is preferably 10 or more, more preferably 20 or more, even more preferably 30 or more, and from the same viewpoint, preferably 200 or less, more preferably 150 or less, and even more preferably 120 or less. Alternatively, in copolymer (A), the average number of moles of AO added to constituent unit (II) and constituent unit (III) is preferably 10 to 200, more preferably 20 to 150, and even more preferably 30 to 120.

[0037] The average number of moles of AO added to constituent units (II) and (III) is the molar ratio of constituent unit (II) to the total number of constituent units constituting copolymer (A). ＩＩ and the molar ratio of constituent unit (III) to all constituent units constituting (A) ＩIＩ Based on the average number of moles added n1 in the monomer-derived constituent unit (II) represented by general formula (A2) and the average number of moles added n2 in the monomer-derived constituent unit (III) represented by general formula (A3), the following formula (1) is used to calculate: Average number of moles added of AO between constituent unit (II) and constituent unit (III) = [Mole ratio of constituent unit (II)] ＩＩ ×n1] + [Molar ratio of constituent unit (II)] ＩIＩ ×n2〕〕 / 〔[Molar ratio of constituent unit (II) ＩＩ ] + [molar ratio of constituent units (III)] ＩIＩ〕〕 (1) [In equation (1), molar ratio ＩＩ This is the molar ratio of constituent unit (II) to all constituent units of copolymer (A), and the molar ratio ＩIＩ n1 is the molar ratio of constituent unit (III) to all constituent units of copolymer (A), n1 is the average number of moles of AO added in general formula (A2), and n2 is the average number of moles of AO added in general formula (A3).

[0038] Copolymer (A) may optionally contain any constituent units other than those corresponding to constituent unit (I), constituent unit (II), and constituent unit (III). The optional constituent units may be one or more types. The optional constituent units may be, for example, methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate, hydroxymethyl acrylate, hydroxyethyl acrylate, hydroxymethyl methacrylate, hydroxyethyl methacrylate, 2-(methacryloyloxy)ethyl phosphate (HEMA-P), allyl sulfonic acid, methallyl sulfonic acid, or salts thereof, or monomer-derived constituent units such as alkali metal salts, alkaline earth metal salts, ammonium salts, or amine salts. Furthermore, any constituent unit may be a constituent unit derived from one or more monomers selected from, for example, (meth)acrylamide, N-methyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, 2-(meth)acrylamide-2-methasulfonic acid, 2-(meth)acrylamide-2-ethanesulfonic acid, 2-(meth)acrylamide-2-propanesulfonic acid, styrene, styrenesulfonic acid, and ω-methoxypolyethylene glycol monomethacrylate, excluding those corresponding to the monomer represented by the general formula (A2) or the monomer represented by the general formula (A3).

[0039] <Composition, etc.> The dispersant for sprayable hydraulic compositions of the present invention contains copolymer (A) in an amount of preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, and preferably 60% by mass or less, more preferably 50% by mass or less, even more preferably 40% by mass or less, from the viewpoint of moldability and nozzle clogging suppression of the hydraulic composition. Alternatively, the dispersant for sprayable hydraulic compositions of the present invention contains copolymer (A) in an amount of preferably 10% by mass or more and 60% by mass or less, more preferably 15% by mass or more and 50% by mass or less, even more preferably 20% by mass or more and 40% by mass or less, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition.

[0040] The dispersant for spray-hardening water compositions of the present invention may optionally contain water. The water is not particularly limited, but examples include tap water, well water, deionized water, and distilled water. Preferably, the amount of water used is the remainder of the dispersant for spray-hardening water compositions (an amount that totals 100% by mass).

[0041] If the dispersant for sprayable hydraulic compositions of the present invention contains water, the dispersant for sprayable hydraulic compositions of the present invention contains water in an amount of 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, preferably 85% by mass or less, more preferably 84% by mass or less, and even more preferably 80% by mass or less. Alternatively, if the dispersant for sprayable hydraulic compositions of the present invention contains water, the dispersant for sprayable hydraulic compositions of the present invention contains water in an amount of 40% by mass or more and 85% by mass or less, more preferably 50% by mass or more and 84% by mass or less, and even more preferably 60% by mass or more and 80% by mass or less, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition.

[0042] The dispersant for sprayable hydraulic compositions of the present invention may optionally contain one or more selected from surfactants, water-soluble polymers (excluding those corresponding to copolymer (A)), foaming agents, dispersants, and thickeners, as long as the effects of the present invention are not impaired. The dispersant for sprayable hydraulic compositions of the present invention may contain these optional components in total, for example, 0% by mass or more and 10% by mass or less, preferably 0% by mass or more and 5% by mass or less.

[0043] In exemplary embodiments, the dispersant for sprayable hydraulic compositions of the present invention may be a dispersant for sprayable hydraulic compositions comprising copolymer (A). In the dispersant for sprayable hydraulic compositions of the present invention, the preferred amount of copolymer (A) can be applied by substituting the preferred content in the above-described dispersant for sprayable hydraulic compositions of the present invention with the amount of copolymer (A).

[0044] <Method for producing a dispersant for spray-applied hydraulic compositions> In an exemplary embodiment, the present invention provides a method for producing a dispersant for spray-applied hydraulic compositions by mixing a copolymer (A) having monomer-derived constituent units (I) represented by the above general formula (A1) and monomer-derived constituent units (II) represented by the above general formula (A2) with water.

[0045] In the method for producing the dispersant for spray-forming hydraulic compositions of the present invention, the preferred embodiments of copolymer (A) and water are the same as the preferred embodiments of copolymer (A) and water in the above-described dispersant for spray-forming hydraulic compositions of the present invention. Furthermore, in the method for producing the dispersant for spray-forming hydraulic compositions of the present invention, any of the optional components listed in the dispersant for spray-forming hydraulic compositions of the present invention may be arbitrarily mixed.

[0046] In the method for producing a dispersant for spray-applied hydraulic compositions of the present invention, the preferred mixing amounts of copolymer (A) and water can be applied by substituting the preferred content of each component in the above-described dispersant for spray-applied hydraulic compositions of the present invention with the mixing amounts.

[0047] <Hydraulic Composition for Spraying> In an exemplary embodiment, the present invention provides a sprayable hydraulic composition containing a dispersant for sprayable hydraulic compositions that contains a copolymer (A) having a monomer-derived constituent unit (I) represented by the above general formula (A1) and a monomer-derived constituent unit (II) represented by the above general formula (A2). The sprayable hydraulic composition of the present invention may be a sprayable hydraulic composition containing the dispersant for sprayable hydraulic compositions of the present invention. Alternatively, the sprayable hydraulic composition of the present invention may be a sprayable hydraulic composition containing the dispersant for sprayable hydraulic compositions of the present invention and a hydraulic powder.

[0048] In the sprayable hydraulic composition of the present invention, preferred embodiments of the copolymer (A) and the dispersant for the sprayable hydraulic composition are the same as preferred embodiments of the copolymer (A) and the dispersant for the sprayable hydraulic composition in the above-described dispersant for the sprayable hydraulic composition of the present invention. Furthermore, the sprayable hydraulic composition of the present invention, or the above-described dispersant for the sprayable hydraulic composition, may optionally contain any of the optional components listed in the dispersant for the sprayable hydraulic composition of the present invention. In the sprayable hydraulic composition of the present invention, preferred embodiments of the content of copolymer (A) and water, etc., contained in the dispersant for the sprayable hydraulic composition are the same as preferred embodiments of the content of copolymer (A) and water, etc., in the dispersant for the sprayable hydraulic composition of the present invention.

[0049] <Hydraulic Powder> The hydraulic composition for spraying of the present invention may contain hydraulic powder. Hydraulic powder is a powder that hardens when mixed with water, and examples include ordinary Portland cement, rapid-hardening Portland cement, ultra-rapid-hardening Portland cement, sulfate-resistant Portland cement, low-heat Portland cement, moderate-heat Portland cement, white Portland cement, alumina cement, calcined clay-containing cement, or eco-cement (e.g., JIS R 5214). Among these, from the viewpoint of expanding the range of hydraulic compositions, cement selected from rapid-hardening Portland cement, ordinary Portland cement, sulfate-resistant Portland cement, and white Portland cement is preferred, and rapid-hardening Portland cement or ordinary Portland cement is more preferred.

[0050] Furthermore, the hydraulic powder may contain blast furnace slag, fly ash, silica fume, anhydrous gypsum, etc., and may also contain non-hydraulic limestone fine powder, etc. The hydraulic powder may be blast furnace cement, fly ash cement, or silica fume cement, which are mixtures of cement with blast furnace slag, fly ash, silica fume, etc.

[0051] <Aggregate> The hydraulic composition for spraying of the present invention may optionally contain aggregate. The aggregate can be selected from fine aggregate and coarse aggregate. Fine aggregate can be those specified in JIS A 0203-2014, number 2311. For example, fine aggregate can be river sand, land sand, mountain sand, sea sand, lime sand, silica sand, and crushed sand thereof, blast furnace slag fine aggregate, ferronickel slag fine aggregate, lightweight fine aggregate (artificial and natural), and recycled fine aggregate. Coarse aggregate can be those specified in JIS A 0203-2014, number 2312. For example, coarse aggregate can be river gravel, land gravel, mountain gravel, sea gravel, lime gravel, crushed stone thereof, blast furnace slag coarse aggregate, ferronickel slag coarse aggregate, lightweight coarse aggregate (artificial and natural), and recycled coarse aggregate. Fine aggregate and coarse aggregate may be mixed together or used as a single type.

[0052] The hydraulic composition for spraying according to the present invention may contain fine aggregate. The amount of fine aggregate used in the hydraulic composition of the present invention is preferably 500 kg / m³. ３ More preferably 600 kg / m ３ In addition, preferably 2,000 kg / m ３ More preferably, 1,700 kg / m ３ The following applies to the hydraulic composition of the present invention. The fine aggregate ratio is preferably 35% or more, more preferably 45% or more, preferably 100% or less, more preferably 70% or less, and even more preferably 65% ​​or less. Here, the fine aggregate ratio is the volume content of fine aggregate in the total aggregate.

[0053] <Water> The sprayable hydraulic composition of the present invention may optionally contain water. Examples of water include tap water, groundwater, lake water, and river water.

[0054] The water-to-hydraulic composition for spraying of the present invention has a water / hydraulic powder ratio (W / C) that is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less, from the viewpoint of moldability, strength development and nozzle clogging suppression of the water-to-hydraulic composition. Alternatively, the water / hydraulic powder ratio (W / C) is preferably 30% by mass or more and 80% by mass or less, more preferably 35% by mass or more and 70% by mass or less, and even more preferably 40% by mass or more and 65% by mass or less, from the same viewpoint. That is, the water-to-hydraulic composition for spraying of the present invention contains water, preferably 30 parts by mass or more, more preferably 35 parts by mass or more, even more preferably 40 parts by mass or more, and preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and even more preferably 65 parts by mass or less, per 100 parts by mass of water-to-hydraulic powder. Alternatively, from the same viewpoint, the hydraulic composition of the present invention contains water in amounts of preferably 30 to 80 parts by mass, more preferably 35 to 70 parts by mass, and even more preferably 40 to 65 parts by mass, per 100 parts by mass of hydraulic powder. This water / hydraulic powder ratio (W / C) is expressed as the ratio of water to hydraulic powder in the hydraulic composition as a mass percentage (mass%), and is calculated as (water / hydraulic powder) × 100. Furthermore, if the hydraulic powder includes powders selected from powders that harden by hydration reactions such as cement, powders with pozzolanic properties, powders with latent hydraulic properties, and stone powder (calcium carbonate powder), the amounts of these are also included in the amount of hydraulic powder in the present invention. Furthermore, if the powder that hardens by hydration reactions contains a high-strength admixture, the amount of the high-strength admixture is also included in the amount of hydraulic powder. This is also true for other parts of mass where the mass of the hydraulic powder is relevant.

[0055] The sprayable hydraulic composition of the present invention contains a dispersant for sprayable hydraulic compositions in an amount of 0.3% by mass or more, more preferably 0.4% by mass or more, and even more preferably 0.5% by mass or more, relative to the hydraulic powder in the hydraulic composition, from the viewpoint of moldability of the hydraulic composition and suppression of nozzle clogging, and preferably 2.0% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less, from the viewpoint of moldability and strength development of the hydraulic composition. Alternatively, the sprayable hydraulic composition of the present invention contains a dispersant for sprayable hydraulic compositions in an amount of 0.3% by mass or more and 2.0% by mass or less, more preferably 0.4% by mass or more and 1.5% by mass or less, and even more preferably 0.5% by mass or more and 1.0% by mass or less, relative to the hydraulic powder in the hydraulic composition, from the viewpoint of moldability of the hydraulic composition, suppression of nozzle clogging, and strength development.

[0056] In the sprayable hydraulic composition of the present invention, the content of the dispersant for the sprayable hydraulic composition is preferably 0.04% by mass or more, more preferably 0.06% by mass or more, and even more preferably 0.08% by mass or more, from the viewpoint of moldability of the hydraulic composition and suppression of nozzle clogging, and from the viewpoint of moldability and strength development of the hydraulic composition, preferably 0.4% by mass or less, more preferably 0.3% by mass or less, and even more preferably 0.2% by mass or less. Alternatively, in the sprayable hydraulic composition of the present invention, the content of the dispersant for the sprayable hydraulic composition is preferably 0.04% by mass or more and 0.4% by mass or less, more preferably 0.06% by mass or more and 0.3% by mass or less, and even more preferably 0.08% by mass or more and 0.2% by mass or less, from the viewpoint of moldability of the hydraulic composition, suppression of nozzle clogging, and strength development.

[0057] <Accelerating Agent> The sprayable hydraulic composition of the present invention may optionally contain an accelerating agent. The accelerating agent can be used in any form, such as powder, liquid, or a combination thereof. Examples of accelerating agents include one or more accelerating agents selected from cement mineral-based accelerating agents and aluminum-based accelerating agents.

[0058] Examples of cement mineral-based rapid setting agents include one or more selected from calcium aluminate, calcium sulfoaluminate, and calcium aluminate. Examples of aluminum-based rapid setting agents include one or more selected from aluminum salts containing aluminum hydroxide, sodium aluminate, potassium aluminate, aluminum sulfate, aluminum chloride, potassium aluminum sulfate, potassium alum, iron alum, and ammonium iron alum. From the viewpoint of strength development, one or more selected from calcium aluminate, calcium sulfoaluminate, calcium aluminate, aluminum sulfate, sodium aluminate, and aluminum sulfate are preferred as the rapid setting agent; one or more selected from calcium aluminate, calcium sulfoaluminate, and aluminum sulfate are more preferred; and one or more selected from calcium aluminate and aluminum sulfate are even more preferred. The quick-setting agent may contain gypsum, alkali carbonates such as sodium carbonate, potassium carbonate, and sodium bicarbonate, sodium sulfate, hydroxide salts, fluorine components, alkanolamines, complex-forming agents, or alkaline earth metal carbonates.

[0059] More specifically, the rapid setting agents include Denka Co., Ltd.'s Denkanatomic series, Denkanatomic US-32, Denkanatomic US-50, Denkanatomic TYPE-5, Denkanatomic TYPE-10, Denkanatomic Z, Natomic L, Natomic LSA, Natomic USS, Natomic HSS, Denka Σ Shot V, and Taiheiyo Material Co., Ltd.'s Taiheiyo Shot Master series, Taiheiyo Shot Master A, Taiheiyo Shot Master A (for high strength), Taiheiyo Shot Master H, and Pozzolith Solution. You can use the Master Lock series from SHONS Co., Ltd., including Master Lock SA160, Master Lock SA161, Master Lock SA167, Master Lock SA170, Master Lock SA178, Master Lock SA143, and Master Lock SA446, or the Cygnit series from Sika Japan Co., Ltd., including Cygnit P10AF, Cygnit L53AF, Cygnit U, Cygnit SA161, Cygnit SA167, Cygnit SA178, Cygnit SA143, and Cygnit SA446.

[0060] <Calcium Aluminate> Calcium aluminate (hereinafter referred to as CA) is made from CaO and Al ２ O ３ A general term for compounds that have hydration activity and whose main component is CaO and / or Al ２ O ３ Compounds in which a portion of the material is substituted with alkali metal oxides, alkaline earth metal oxides, silicon dioxide, titanium dioxide, iron oxide, alkali metal halides, alkaline earth metal halides, alkali metal sulfates, and alkaline earth metal sulfates, or CaO and Al ２ O ３ It is a substance in which small amounts of these are dissolved in a substance whose main component is [substance name], and the CA compounds may be crystalline or amorphous.

[0061] A specific example of a crystalline material of the CA group is CaO, where C and Al are used. ２ O ３ If we consider A, then C3A, C14A5 (where alkali metals are dissolved in it), CA, C12A7, C11A7, and CaF are examples of C3A. ２ C4A・Fe ２ O ３ , and C3A3・CaSO４ Examples include Na. ２ O, K ２ O, Li ２ It may contain oxygen. Amorphous calcium aluminate is preferred because it has good rapid setting properties.

[0062] In this embodiment, the calcium aluminate may contain trace amounts of alkali metals and / or alkaline earth metals from the industrial raw materials, and there is a possibility that some CA compounds containing these alkali metals and / or alkaline earth metals may be formed. However, the presence of these small amounts of alkali metals and / or alkaline earth metals does not limit the process in any way.

[0063] CaO / Al of calcium aluminate ２ O ３ The molar ratio is not particularly limited, but considering the strength development in the very early stages, it is preferably 2.0 to 3.0, and more preferably 2.2 to 2.8. A molar ratio of 2.0 or higher can improve the setting properties in the very early stages, and a molar ratio of 3.0 or lower makes it easier to obtain good long-term strength development.

[0064] The Blaine specific surface area of ​​calcium aluminate (hereinafter sometimes simply referred to as "Blaine") is 4,000 cm². ２ / g or more 8,000cm ２ It is preferable that it be less than or equal to 5,000 cm². ２ / g or more 7,000cm ２ It is more preferable that the amount is less than or equal to / g. The specific surface area is 4,000 cm². ２ / g or more 8,000cm ２ Having a value of less than / g makes it easier to achieve initial strength development and improves the handling properties of mortar and / or concrete during spraying.

[0065] <Alum> Alum is effective in promoting the loss of fluidity in cement mortar and cement concrete immediately after mixing, and in promoting the development of strength over about one day. The alum is not particularly limited, but any type of alum can be used or used in combination, for example, potassium alum, chromium alum, iron alum, ammonium alum, sodium alum, and natural alum. It is especially preferable to include at least one selected from the group consisting of potassium alum, sodium alum, and ammonium alum as a substance that causes the loss of fluidity in cement mortar and cement concrete.

[0066] <Gypsum> Any type of gypsum can be used: anhydrous, hemihydrate, or dihydrate. Of these, anhydrous gypsum is preferred from the viewpoint of good strength development. The particle size of the gypsum should be 2,000 cm² in Blaine specific surface area from the viewpoint of initial strength development. ２ Preferably, it is 3,000 cm² or more. ２ / g or more 6,000cm ２ A value of less than or equal to / g is more preferable. The Blaine specific surface area value in this specification can be determined in accordance with JIS R 5201 (Physical Testing Methods for Cement).

[0067] <Hydroxide Salts> Hydroxide salts include hydroxide salts of alkali metals or alkaline earth metals. Examples of hydroxide salts include one or more selected from sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, and calcium hydroxide. Among these, calcium hydroxide is preferred in terms of economy and strength development. Calcium hydroxide is an effective material for ensuring very early fluidity reduction and long-term strength development. Calcium hydroxide is not particularly limited, but also includes slaked lime produced when quicklime is hydrated, and carbide slag produced when carbide is hydrated. Commercially available calcium hydroxide can also be used, and any combination of the above is also possible.

[0068] The Blaine specific surface area of ​​calcium hydroxide is 5,000 cm². ２ / g or more 15,000cm ２ Preferably less than / g, and 7,000 cm２ / g or more 13,000cm ２ It is more preferable that the specific surface area is 5,000 cm² or less. ２ / g or more 15,000cm ２ By keeping the amount below / g, rapid hardening and long-term strength development can be ensured, making it easier to obtain good initial strength development.

[0069] <Alkali Carbonate> Alkali carbonate refers to alkali metal carbonate salts, which can significantly improve the setting properties and initial strength development of powdered rapid setting agents. Alkali carbonate is not particularly limited, but examples include one or more selected from lithium carbonate, sodium carbonate, sodium sesquicarbonate, potassium carbonate, potassium bicarbonate, sodium bicarbonate, and sodium bicarbonate. Sodium carbonate, potassium carbonate, sodium sesquicarbonate, sodium bicarbonate, and sodium bicarbonate are particularly effective in setting and initial strength development, and it is possible to combine one or more of these. Preferably, it is at least one selected from the group consisting of sodium carbonate, sodium sesquicarbonate, sodium bicarbonate, and potassium carbonate.

[0070] <Fluorine Components> Examples of fluorine components include fluoride salts or hydrofluoric acid, which can significantly improve the setting properties and initial strength development of the rapid setting agent. The raw material compound containing the fluorine component is not particularly limited and is not limited to any compound that contains fluorine and is soluble or dispersed in water. Examples of raw material compounds containing the fluorine component include one or more fluorine compounds selected from fluoride salts, siliceous fluoride salts, boron fluoride salts, organofluorine compounds, and hydrofluoric acid. Examples of the above fluoride salts include lithium fluoride, sodium fluoride, potassium fluoride, calcium fluoride, aluminum fluoride, and cryolite. Cryolite can be either natural or synthesized. Examples of siliceous fluoride salts include ammonium siliceous fluoride, sodium siliceous fluoride, potassium siliceous fluoride, and magnesium siliceous fluoride. Examples of boron fluoride salts include boron fluoride, boron trifluoride, boron trifluoride monoethylamine complex, boron trifluoride acetate complex, boron trifluoride triethanolamine, ammonium borofluoride, sodium borofluoride, potassium borofluoride, and ferrous borofluoride. The raw material compound containing the fluorine component is preferably one or more selected from fluoride salts and siliceous fluoride salts due to its high safety, low manufacturing cost, and excellent coagulation properties.

[0071] <Alkanolamines> Alkanolamines refer to organic compounds having an N-R-OH structure in their structural formula, and can significantly improve the setting properties and initial strength development of rapid setting agents. Here, R is an atomic group called an alkylene group or arylene group. Examples include linear alkylene groups such as methylene groups, ethylene groups, and n-propylene groups, branched alkylene groups such as isopropylene groups, and arylene groups having aromatic rings such as phenylene groups and torylene groups. R may be bonded to a nitrogen atom at two or more locations, and part or all of R may have a cyclic structure. Furthermore, R may be bonded to multiple hydroxyl groups, and some of the alkyl groups may contain elements other than carbon and hydrogen, such as sulfur, fluorine, chlorine, and oxygen. Examples of alkanolamines include one or more selected from ethanolamine, diethanolamine, triethanolamine, N-methyldiethanolamine, N,N-dimethylethanolamine, N,N-dibutylethanolamine, N-(2-aminoethyl)ethanolamine, borontriethanolamine trifluoride, and derivatives thereof. Diethanolamine, N,N-dimethylethanolamine, or mixtures thereof are preferred, and a mixture of diethanolamine and N,N-dimethylethanolamine is more preferred.

[0072] <Complex Forming Agent> The complex forming agent stabilizes metal ions in the rapid setting agent, and is not particularly limited as long as it is a substance that can be used for this purpose. For example, organic acids having at least one carboxyl group, preferably one to three, and more preferably two to three, are available. Furthermore, substances having one to three hydroxyl groups and / or one to three amino groups can also be used. Examples of complex-forming agents include (1) monocarboxylic acids such as formic acid, acetic acid, and propionic acid; (2) dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, and phthalic acid; (3) tricarboxylic acids such as trimellitic acid and tricarbarylic acid; (4) oxymonocarboxylic acids such as hydroxybutyric acid, lactic acid, and salicylic acid; (5) oxydicarboxylic acids such as malic acid; (6) aminocarboxylic acids such as aspartic acid and glutamic acid; and (7) ethylenediaminetetraacetic acid (EDTA) and trans-1,2-diaminocyclohexanetetraacetic acid. Examples of complex-forming agents include aminopolycarboxylic acids such as (CyDTA), (8) phosphonic acids such as ethylenediaminetetra(methylenephosphonic acid) [EDTPO], ethylenediaminedi(methylenephosphonic acid) [EDDPO], nitrilotris(methylenephosphonic acid) [NTPO], and 1-hydroxyethylidene-1,1'-diphosphonic acid [HEDPO], (9) condensed phosphoric acids such as phosphoric acid, tripolyphosphate, and hexametaphosphate, and (10) diketones such as acetylacetone and hexafluoroacetylacetone. In the present invention, one or more of these complex-forming agents can be used. Preferably, the complex-forming agent is at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, and condensed phosphoric acids.

[0073] <Alkaline Earth Metal Carbonates> Alkaline earth metal carbonates refer to carbonates of alkaline earth metals and prevent the adhesion of fasteners to pipes and blockage of pipes, etc. Examples of alkaline earth metal carbonates include one or more selected from calcium carbonate, magnesium carbonate, and barium carbonate, with one or more selected from calcium carbonate and magnesium carbonate being preferred. Calcium carbonate is particularly preferred for its effectiveness in preventing adhesion to pipes and blockage of pipes, and it is even more preferable to use calcium carbonate in combination with sodium carbonate.

[0074] If the sprayable hydraulic composition of the present invention contains a rapid-setting agent, the sprayable hydraulic composition of the present invention contains the rapid-setting agent in an amount of 0.1% by mass or more, more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, and, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less, relative to the hydraulic powder in the hydraulic composition. Alternatively, if the sprayable hydraulic composition of the present invention contains a rapid-setting agent, the rapid-setting agent in an amount of 0.1% by mass or more and 15% by mass or less, more preferably 0.2% by mass or more and 12% by mass or less, relative to the hydraulic powder in the hydraulic composition, from the same viewpoint.

[0075] If the sprayable hydraulic composition of the present invention contains a rapid setting agent, the content of the rapid setting agent in the sprayable hydraulic composition of the present invention is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, even more preferably 0.05% by mass or more, and from the same viewpoint, preferably 3% by mass or less, more preferably 2.5% by mass or less, and even more preferably 2% by mass or less. Alternatively, if the sprayable hydraulic composition of the present invention contains a rapid setting agent, the content of the rapid setting agent in the sprayable hydraulic composition of the present invention is preferably 0.01% by mass or more and 3% by mass or less, more preferably 0.02% by mass or more and 2.5% by mass or less, and even more preferably 0.05% by mass or more and 2% by mass or less, from the same viewpoint.

[0076] <Water-soluble polymers other than copolymer (A)> The hydraulic composition for spraying of the present invention may optionally contain water-soluble polymers [excluding those corresponding to copolymer (A)] [hereinafter referred to as component (B)] from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition. Component (B) may be one or more types. Here, water solubility of component (B) means that 0.01 g or more dissolves in 100 g of water at 20°C.

[0077] The weight-average molecular weight of component (B) is preferably 5,000 or more, more preferably 25,000 or more, even more preferably 50,000 or more, even more preferably 100,000 or more, and preferably 10,000,000 or less, more preferably 8,000,000 or less, even more preferably 5,000,000 or less, and even more preferably 1,000,000 or less, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition. Alternatively, the weight-average molecular weight of component (B) is preferably 5,000 or more and 10,000,000 or less, more preferably 25,000 or more and 8,000,000 or less, even more preferably 50,000 or more and 5,000,000 or less, and even more preferably 100,000 or more and 1,000,000 or less, from the same viewpoint. The weight-average molecular weight of component (B) can be determined, for example, by gel permeation chromatography under the following conditions. • Apparatus: HLC-8320 GPC (manufactured by Tosoh Corporation, integrated detector) • Column: Tosoh Corporation, product name: TSK-GEL guardcolumn PWXL Tosoh Corporation, product name: TSK-GEL GMPWXL Tosoh Corporation, product name: TSK-GEL GMPWXL • Mobile phase: 0.2 mol / L phosphate buffer (potassium dihydrogen phosphate, disodium hydrogen phosphate aqueous solution, pH=7) / acetonitrile = 90 / 10 (volume ratio) • Detector: Differential refractive index detector • Column temperature: 40°C • Flow rate: 0.5 mL / min • Conversion standard substance: Polyethylene oxide [manufactured by Tosoh Corporation] • Sample: An aqueous polymer solution containing 5 mg of solids is mixed with ultrapure water to prepare a total volume of 10 mL. 100 μL of this prepared solution is taken and injected into the column.

[0078] Component (B) is preferably one or more selected from polyethylene oxide [hereinafter referred to as component (B1)], polymers containing monomer-derived units including carboxyl groups or their salts [hereinafter referred to as component (B2)], and cellulose-based polymers [hereinafter referred to as component (B3)], from the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition.

[0079] The weight-average molecular weight of component (B1) is preferably 200,000 or more, more preferably 400,000 or more, even more preferably 600,000 or more, and even more preferably 800,000 or more, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, and preferably 10,000,000 or less, more preferably 5,000,000 or less, even more preferably 2,000,000 or less, even more preferably 1,500,000 or less, and even more preferably 1,200,000 or less, from the viewpoint of discharge workability of the hydraulic composition for spraying. Alternatively, the weight-average molecular weight of component (B1) is preferably 200,000 to 10,000,000, more preferably 400,000 to 5,000,000, even more preferably 600,000 to 2,000,000, even more preferably 800,000 to 1,500,000, and even more preferably 800,000 to 1,200,000, from the viewpoint of moldability, strength development, nozzle clogging suppression, and discharge workability of the hydraulic composition for spraying.

[0080] (B1) For commercially available polyethylene oxide products, the weight-average molecular weight may be the value based on the product information (catalog, etc.). Even if the weight-average molecular weight is unknown, since the weight-average molecular weight of polyethylene oxide correlates with the viscosity of the aqueous solution, an approximate value can be determined using the method described below.

[0081] <Weight-Average Molecular Weight of Polyethylene Oxide> Prepare aqueous solutions of various concentrations (hereinafter referred to as "sample aqueous solutions") from the polyethylene oxide to be measured, referring to the reference table 1 below. Measure the viscosity of the sample aqueous solutions using a B-type viscometer under the conditions of 25°C, No. 2 rotor, 30 rpm, and after 1 minute. Determine the corresponding weight-average molecular weight from the obtained viscosity. Note that this reference table was created using polyethylene oxide with known weight-average molecular weights. In the reference table, PEO stands for polyethylene oxide.

[0082]

[0083] (B2) Polymers containing constituent units derived from monomers containing carboxyl groups or salts thereof are preferred from the viewpoint of moldability, strength development and nozzle clogging suppression of hydraulic compositions, and polymers containing constituent units derived from one or more monomers selected from acrylic acid, methacrylic acid, and their salts [hereinafter referred to as monomer (b2-1)]. Examples of acrylic acid and methacrylic acid salts include one or more selected from sodium salts, potassium salts, ammonium salts, aminium salts, and calcium salts. Monomer (b2-1) is preferably one or more selected from acrylic acid and its salts.

[0084] Component (B2) may include constituent units derived from monomers other than those corresponding to monomer (b2-1) [hereinafter referred to as monomer (b2-2)]. Monomer (b2-2) may include, for example, unsaturated carboxylic acids such as itaconic acid, maleic acid, fumaric acid, citraconic acid, aconitic acid, and crotonic acid; unsaturated carboxylic acid anhydrides such as maleic anhydride and citraconic anhydride; unsaturated carboxymethyl carboxylates such as monomethyl itaconic acid, monobutyl itaconic acid, and monoethyl maleate; unsaturated sulfonic acids such as vinyl sulfonic acid, methallyl sulfonic acid, and 2-(meth)acrylamide-2-methylpropanesulfonic acid; unsaturated phosphoric acids such as 2-(meth)acryloyloxy)ethyl phosphate and bis[2-(meth)acryloyloxy)ethyl hydrogen phosphate; unsaturated phenols such as vinylphenol; acrylonitrile and metac Examples include vinyl esters of aliphatic carboxylic acids having 3 to 18 carbon atoms, such as cyanovinyl lilonitrile, vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl stearate, vinyl octylate, and vinyl neodecanoate; vinyl ether monomers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, and phenyl vinyl ether; polyfunctional vinyl monomers such as allyl methacrylate; unsaturated hydrocarbons such as ethylene, styrene, and butadiene; and unsaturated amide compounds such as methacrylamide, N-isopropylacrylamide, N-isopropylmethacrylamide, and N-vinylpyrrolidone. One or more of these can be used.

[0085] The proportion of monomer (b2-1) among the total monomers constituting component (B2) is preferably 60 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, and preferably 100 mol% or less, and may be 100 mol%. Alternatively, the proportion of monomer (b2-1) among the total monomers constituting component (B2) is preferably 60 mol% or more and 100 mol% or less, more preferably 70 mol% or more and 100 mol% or less, and even more preferably 80 mol% or more and 100 mol% or less.

[0086] (B2) Component is preferably one or more selected from polyacrylic acid, polymethacrylic acid, and salts thereof, from the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition, and more preferably one or more selected from polyacrylic acid and salts thereof.

[0087] The weight-average molecular weight of component (B2) is preferably 10,000 or more, more preferably 15,000 or more, even more preferably 20,000 or more, even more preferably 25,000 or more, and preferably 6,500,000 or less, more preferably 5,000,000 or less, even more preferably 3,500,000 or less, even more preferably 2,500,000 or less, even more preferably 2,000,000 or less, even more preferably 1,000,000 or less, even more preferably 500,000 or less, even more preferably 100,000 or less, even more preferably 50,000 or less, and even more preferably 30,000 or less, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition. Alternatively, the weight-average molecular weight of component (B2) is preferably 10,000 to 6,500,000, more preferably 15,000 to 5,000,000, even more preferably 20,000 to 3,500,000, even more preferably 25,000 to 2,500,000, even more preferably 25,000 to 2,000,000, even more preferably 25,000 to 1,000,000, even more preferably 25,000 to 500,000, even more preferably 25,000 to 100,000, even more preferably 25,000 to 50,000, and even more preferably 25,000 to 30,000.

[0088] (B2) The weight-average molecular weight of component (B2) can also be determined by gel permeation chromatography under the following conditions: Column: GMPWXL-GMPWXL (anion) manufactured by Tosoh Corporation Detector: Differential refractometer Eluent: 0.2 M phosphate buffer / acetonitrile = 9 / 1 Standard: Polyethylene glycol equivalent (monodisperse polyethylene glycol with known molecular weight, molecular weight: 21,000, 44,200, 101,000, 185,000, 580,000, 977,000) Conditions: Column temperature: 40°C, flow rate: 0.5 mL / min, concentration: 2 mg / mL

[0089] The cellulose polymer of component (B3) includes modified cellulose, such as carboxyalkyl, alkyl, or hydroxyalkyl modified cellulose, represented by carboxymethylcellulose, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, and hydroxypropylmethylcellulose.

[0090] The viscosity of an aqueous solution or dispersion of component (B3) at 25°C, with a concentration of 1% by mass, is preferably 10 mPa·s or more, more preferably 30 mPa·s or more, even more preferably 60 mPa·s or more, even more preferably 300 mPa·s or more, even more preferably 2,000 mPa·s or more, and from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, is preferably 7,000 mPa·s or less, more preferably 6,000 mPa·s or less, and even more preferably 5,000 mPa·s or less. Alternatively, the viscosity of an aqueous solution or dispersion of component (B3) at 25°C at a concentration of 1% by mass is preferably 10 mPa·s or more and 7,000 mPa·s or less, more preferably 30 mPa·s or more and 6,000 mPa·s or less, even more preferably 60 mPa·s or more and 5,000 mPa·s or less, even more preferably 300 mPa·s or more and 5,000 mPa·s or less, and even more preferably 2,000 mPa·s or more and 5,000 mPa·s or less. The above viscosity is measured using a B-type viscometer (VISCOMETER, MODEL BM, manufactured by Tokyo Keiki Co., Ltd., rotor No. 2) at a rotation speed of 60 rpm.

[0091] The weight-average molecular weight of component (B3) is preferably 10,000 or more, more preferably 100,000 or more, even more preferably 400,000 or more, even more preferably 800,000 or more, even more preferably 1,500,000 or more, and preferably 20,000,000 or less, even more preferably 10,000,000 or less, and even more preferably 6,000,000 or less, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition. Alternatively, the weight-average molecular weight of component (B3) is preferably 10,000 to 20,000,000, more preferably 100,000 to 10,000,000, even more preferably 400,000 to 6,000,000, even more preferably 800,000 to 6,000,000, and even more preferably 1,500,000 to 6,000,000. The above weight-average molecular weight was measured by gel permeation chromatography based on the following measurement conditions.

[0092] <Method for measuring weight-average molecular weight> The weight-average molecular weight of component (B3) can be measured by GPC (gel permeation chromatography), and the weight-average molecular weight (Mw) can be determined using a converted standard substance. The GPC measurement conditions are shown below. • Apparatus: HLC-8320 GPC (manufactured by Tosoh Corporation, integrated detector) • Column: Tosoh Corporation, product name: TSK-GEL guardcolumn PWXL Tosoh Corporation, product name: TSK-GEL GMPWXL Tosoh Corporation, product name: TSK-GEL GMPWXL • Mobile phase: 0.2 mol / L phosphate buffer (potassium dihydrogen phosphate, disodium hydrogen phosphate aqueous solution, pH=7) / acetonitrile = 90 / 10 (volume ratio) • Detector: Differential refractive index detector • Column temperature: 40°C • Flow rate: 0.5 mL / min • Conversion standard substance: Polyethylene oxide [manufactured by Tosoh Corporation] • Sample: An aqueous polymer solution containing 5 mg of solids is mixed with ultrapure water to prepare a total volume of 10 mL. 100 μL of this prepared solution is taken and injected into the column.

[0093] (B3) Component is preferably one or more selected from carboxymethylcellulose and its salts, hydroxyethylcellulose, and hydroxypropylmethylcellulose, from the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition, and carboxymethylcellulose or its salt is more preferred. Examples of carboxymethylcellulose salts include alkali metal salts such as sodium salt and potassium salt, and ammonium salt. From the viewpoint of availability, alkali metal salts are preferred for carboxymethylcellulose salts, and sodium salts are more preferred.

[0094] The degree of etherification of carboxymethylcellulose or its salt in component (B3) is preferably 0.5 or higher, more preferably 0.55 or higher, even more preferably 0.6 or higher, and from the same viewpoint, preferably 1.5 or lower, more preferably 1.3 or lower, and even more preferably 1.0 or lower. Alternatively, from the same viewpoint, this degree of etherification is preferably 0.5 to 1.5, more preferably 0.55 to 1.3, and even more preferably 0.6 to 1.0. The degree of etherification of carboxymethylcellulose or its salt in component (B3) refers to the degree of substitution of carboxymethyl groups per glucose unit in carboxymethylcellulose or its salt in component (B3). When component (B3) is sodium carboxymethylcellulose, its degree of etherification is measured by the following method, for example, according to the CMC Industry Association analytical method (ashing method). The degree of etherification of component (B3) can also be measured by the same method when component (B3) is a salt of carboxymethylcellulose other than sodium.

[0095] <Measurement of the degree of etherification of sodium carboxymethylcellulose> 1 g of sodium carboxymethylcellulose is accurately weighed, placed in a magnetic crucible, and ashed at 600°C. The sodium oxide produced by ashing is titrated with N / 10 sulfuric acid using phenolphthalein as an indicator. The degree of etherification can be calculated by substituting the titration volume Y mL per 1 g of sodium carboxymethylcellulose into the following formula: Degree of etherification = (162 × Y) / (10,000 - 80 × Y)

[0096] (B3) The carboxymethylcellulose or salt thereof of component (B3) is preferably one or more selected from the group consisting of carboxymethylcellulose and sodium carboxymethylcellulose, with sodium carboxymethylcellulose being more preferred, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition. Examples of commercially available sodium carboxymethylcellulose include the CMC Daicel series from Daicel Corporation, the Sunrose series from Nippon Paper Industries Ltd., and the Selogen series from Daiichi Kogyo Seiyaku Co., Ltd.

[0097] Component (B) is preferably one or more selected from polyethylene oxide, polyacrylic acid and its salts, carboxymethylcellulose and its salts, and hydroxypropylmethylcellulose, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, and more preferably one or more selected from polyethylene oxide, carboxymethylcellulose and its salts, and hydroxypropylmethylcellulose.

[0098] If the sprayable hydraulic composition of the present invention contains component (B), the sprayable hydraulic composition of the present invention contains component (B) in an amount of 0.005% by mass or more, more preferably 0.01% by mass or more, even more preferably 0.015% by mass or more, even more preferably 0.019% by mass or more, relative to the hydraulic powder in the hydraulic composition, and from the viewpoint of moldability, strength development and nozzle clogging suppression, preferably 0.5% by mass or less, more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less. Alternatively, if the sprayable hydraulic composition of the present invention contains component (B), the amount of component (B) in an amount of 0.005% by mass or more and 0.5% by mass or less, more preferably 0.01% by mass or more and 0.2% by mass or less, relative to the hydraulic powder in the hydraulic composition, from the same viewpoint, preferably 0.015% by mass or more and 0.1% by mass or less, and even more preferably 0.019% by mass or more and 0.1% by mass or less.

[0099] When the sprayable hydraulic composition of the present invention contains component (B), the content of component (B) in the sprayable hydraulic composition of the present invention is preferably 0.001% by mass or more, more preferably 0.004% by mass or more, even more preferably 0.01% by mass or more, even more preferably 0.02% by mass or more, even more preferably 0.05% by mass or more, and from the same viewpoint, preferably 2% by mass or less, more preferably 1.5% by mass or less, and even more preferably 1.0% by mass or less. Alternatively, if the sprayable hydraulic composition of the present invention contains component (B), the content of component (B) in the sprayable hydraulic composition of the present invention is preferably 0.001% by mass or more and 2% by mass or less, more preferably 0.004% by mass or more and 1.5% by mass or less, even more preferably 0.01% by mass or more and 1.0% by mass or less, even more preferably 0.02% by mass or more and 1.0% by mass or less, and even more preferably 0.05% by mass or more and 1.0% by mass or less.

[0100] <Aluminosilicate> The hydraulic composition for spraying of the present invention may optionally contain (C) aluminosilicate [hereinafter referred to as (C) component] from the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition. One or more types of aluminosilicate may be used in combination.

[0101] (C) The aluminosilicate component is SiO ２ and Al ２ O ３This is a general term for compounds whose main component is clay minerals [hereinafter referred to as (C1) component], metakaolin, calcined clay, fly ash, incinerator ash [including but not limited to rice husks, sugarcane leaf ash, palm oil, boiler ash, paper waste sludge ash, municipal solid waste ash, and furnace bottom ash], natural pozzolanes, volcanic ash, blast furnace slag [from steel or iron], other industrial crushed slag [including but not limited to phosphorus, ferronickel, ferrochrome magnesia-iron, copper, nickel, and titan-iron], mine tailings or waste [including but not limited to coal gang and red mud]. Examples include one or more selected from ], zeolite, feldspar, framework aluminosilicate, and synthetic glass precursor [a mixture of silicate and aluminate], and preferably one or more selected from component (C1), metakaolin, incinerator ash, volcanic ash, natural pozzolanic acid, fly ash, and blast furnace slag.

[0102] The degree of swelling of component (C) is preferably 4 mL / 2 g or more, more preferably 10 mL / 2 g or more, even more preferably 15 mL / 2 g or more, and preferably 50 mL / 2 g or less, more preferably 48 mL / 2 g or less, even more preferably 42 mL / 2 g or less, and even more preferably 36 mL / 2 g or less, from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition. Alternatively, the degree of swelling of component (C) is preferably 4 mL / 2 g or more and 50 mL / 2 g or less, more preferably 10 mL / 2 g or more and 48 mL / 2 g or less, even more preferably 15 mL / 2 g or more and 42 mL / 2 g or less, and even more preferably 15 mL / 2 g or more and 36 mL / 2 g or less, from the same viewpoint. This degree of swelling is measured according to the swelling test method for bentonite (powder) of the Japan Bentonite Industry Association JBAS104:77. Specifically, 2.0 g of the sample, adjusted to a moisture content of 8.0% by mass, is added in approximately 10 portions to a 100 mL stoppered graduated cylinder containing 100 mL of distilled water. Each time, the previous addition is allowed to settle at the bottom of the graduated cylinder before the next addition. After 24 hours, the apparent volume of the sample mass at the bottom of the graduated cylinder, after swelling, is read from the graduated cylinder's scale and expressed as the degree of swelling (mL / 2 g).

[0103] The clay mineral of component (C1) can be one or more selected from layered silicates, for example, and more specifically, one or more selected from bentonite, kaolinite, synthetic mica, smectite, clay, talc, montmorillonite, illite, gluconite, chlorite, hectorite, saponite, stevensite, nontronite, and sericite. Among these, the clay mineral of component (C1) is preferably one or more selected from bentonite, kaolinite, montmorillonite, and smectite, more preferably one or more selected from bentonite and kaolinite, and even more preferably bentonite.

[0104] If the sprayable hydraulic composition of the present invention contains component (C), the sprayable hydraulic composition of the present invention contains component (C) in an amount of 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.15% by mass or more, even more preferably 0.2% by mass or more, relative to the hydraulic powder in the hydraulic composition, and from the viewpoint of moldability, strength development and nozzle clogging suppression of the hydraulic composition, preferably 5% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less. Alternatively, if the sprayable hydraulic composition of the present invention contains component (C), the sprayable hydraulic composition of the present invention contains component (C) in an amount of 0.05% by mass or more and 5% by mass or less, more preferably 0.1% by mass or more and 2% by mass or less, even more preferably 0.15% by mass or more and 1% by mass or less, relative to the hydraulic powder in the hydraulic composition, from the same viewpoint.

[0105] If the sprayable hydraulic composition of the present invention contains component (C), the content of component (C) in the sprayable hydraulic composition of the present invention is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, even more preferably 0.12% by mass or more, and from the same viewpoint, preferably 2% by mass or less, more preferably 1% by mass or less, even more preferably 0.5% by mass or less, and even more preferably 0.25% by mass or less. Alternatively, if the sprayable hydraulic composition of the present invention contains component (C), the content of component (C) in the sprayable hydraulic composition of the present invention is preferably 0.01% by mass or more and 2% by mass or less, more preferably 0.05% by mass or more and 1% by mass or less, even more preferably 0.1% by mass or more and 0.5% by mass or less, and even more preferably 0.12% by mass or more and 0.25% by mass or less.

[0106] The sprayable hydraulic composition of the present invention may optionally contain one or more of the following: a high-performance water-reducing agent, a high-performance AE water-reducing agent, a water-reducing agent containing an AE water-reducing agent and a fluidizing agent, an expanding agent, a hardening accelerator, a hardening retarder, a cement polymer (excluding those corresponding to copolymer (A) or (B) component), a foaming agent, a waterproofing agent, a rust inhibitor, a shrinkage reducing agent, a pigment, a fiber, a water-repellent agent, an efflorescence inhibitor, a thickening agent, a foaming agent, etc.

[0107] Examples of objects to which the hydraulic composition of the present invention is sprayed include tunnels for roads, railways, and waterways, slopes formed by excavation and embankment, underground spaces, and concrete structures that are subject to repair by spraying methods.

[0108] In exemplary embodiments, the sprayable hydraulic composition of the present invention may be a sprayable hydraulic composition comprising a dispersant for sprayable hydraulic compositions containing a copolymer (A) having monomer-derived constituent units (I) represented by the general formula (A1) and monomer-derived constituent units (II) represented by the general formula (A2), a hydraulic powder, and water. The sprayable hydraulic composition of the present invention may be a sprayable hydraulic composition comprising a dispersant for sprayable hydraulic compositions of the present invention, a hydraulic powder, and water. The sprayable hydraulic composition of the present invention may further optionally contain any of the optional components described in the sprayable hydraulic composition of the present invention above. Furthermore, in the sprayable hydraulic composition of the present invention, the preferred amounts of the dispersant for sprayable hydraulic compositions, hydraulic powder, water, and optional components can be applied by substituting the preferred content in the sprayable hydraulic composition of the present invention above for the preferred amounts.

[0109] <Method for Producing a Hydraulic Composition for Spraying> In an exemplary embodiment, the present invention provides a method for producing a hydraulic composition for spraying, comprising mixing a dispersant for a hydraulic composition for spraying, which includes a copolymer (A) having a monomer-derived constituent unit (I) represented by the above general formula (A1) and a monomer-derived constituent unit (II) represented by the above general formula (A2), with a hydraulic powder and water. The method for producing a hydraulic composition for spraying according to the present invention may be a method for producing a hydraulic composition for spraying, which involves mixing the dispersant for a hydraulic composition for spraying according to the present invention with a hydraulic powder and water.

[0110] In the method for producing a sprayable hydraulic composition of the present invention, preferred embodiments of the copolymer (A) and the dispersant for the sprayable hydraulic composition are the same as preferred embodiments of the copolymer (A) and the dispersant for the sprayable hydraulic composition in the above-described dispersant for the sprayable hydraulic composition of the present invention. Furthermore, preferred embodiments of the hydraulic powder and water are the same as preferred embodiments of the hydraulic powder and water in the sprayable hydraulic composition of the present invention. In addition, in the method for producing a sprayable hydraulic composition of the present invention, the sprayable hydraulic composition or the dispersant for the sprayable hydraulic composition may optionally contain any of the components listed in the dispersant for the sprayable hydraulic composition or the sprayable hydraulic composition of the present invention.

[0111] In the method for producing a sprayable hydraulic composition of the present invention, the preferred embodiment of the content of copolymer (A) contained in the dispersant for the sprayable hydraulic composition is the same as the preferred embodiment of the content of copolymer (A) in the dispersant for the sprayable hydraulic composition of the present invention. Furthermore, in the method for producing a sprayable hydraulic composition of the present invention, the amount or ratio of mixing of the dispersant for the sprayable hydraulic composition, hydraulic powder, and water can be applied by substituting the content or mass ratio of each component in the sprayable hydraulic composition of the present invention for the amount or ratio of mixing. The same applies to the spraying method, which will be described in detail later.

[0112] <Spraying Method> In an exemplary embodiment, the present invention provides a spraying method comprising mixing a dispersant for a sprayable hydraulic composition, a hydraulic powder, and water containing a copolymer (A) having a monomer-derived constituent unit (I) represented by the above general formula (A1) and a monomer-derived constituent unit (II) represented by the above general formula (A2), and spraying the mixture onto an object. The spraying method of the present invention may also be a spraying method in which the sprayable hydraulic composition of the present invention is sprayed onto an object. Furthermore, the dispersant for the sprayable hydraulic composition may be the dispersant for the sprayable hydraulic composition of the present invention.

[0113] The spraying method of the present invention is preferably a wet spraying method. Examples of the wet spraying method include mixing and kneading a dispersant for spraying hydraulic composition, hydraulic powder, aggregate, and water, pumping the mixture under air pressure, and optionally adding and mixing a quick-setting agent before spraying. The spraying method of the present invention is preferably a spraying method in which a hydraulic composition for spraying containing the dispersant for spraying hydraulic composition of the present invention, water, hydraulic powder, and aggregate is sprayed onto the target object. The dispersant for spraying hydraulic composition of the present invention may be mixed with water, hydraulic powder, and aggregate to produce a hydraulic composition, and then mixed with the hydraulic composition using a mixer.

[0114] In the spraying method of the present invention, when the sprayable hydraulic composition of the present invention is sprayed onto an object by air pressure, the air pressure used to spray the hydraulic composition onto the object is preferably 0.2 MPa or higher, more preferably 0.3 MPa or higher, even more preferably 0.4 MPa or higher, and from the same viewpoint, preferably 1.2 MPa or lower, more preferably 1.0 MPa or lower, even more preferably 0.8 MPa or lower, and even more preferably 0.6 MPa or lower. Alternatively, in the spraying method of the present invention, when the sprayable hydraulic composition of the present invention is sprayed onto an object by air pressure, the air pressure used to spray the hydraulic composition onto the object is preferably 0.2 MPa or higher and 1.2 MPa or lower, more preferably 0.3 MPa or higher and 1.0 MPa or lower, even more preferably 0.4 MPa or higher and 0.8 MPa or lower, and even more preferably 0.4 MPa or higher and 0.6 MPa or lower. It is preferable that the pressure used to air-feed the sprayable hydraulic composition of the present invention is within the above range.

[0115] The spraying method of the present invention will be described in detail with specific examples. However, the spraying method of the present invention is not limited in any way based on these specific examples. In the spraying method of the present invention, first, the spraying hydraulic composition is manufactured by mixing the dispersant for the spraying hydraulic composition of the present invention, hydraulic powder, aggregate, and water. The hydraulic composition manufactured by mixing hydraulic powder, aggregate, and water, and furthermore, the hydraulic composition of the present invention, has a water / hydraulic powder ratio (W / C) [mass percentage of water and hydraulic powder in the hydraulic composition (mass%)] which is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less. Alternatively, the water / hydraulic powder ratio (W / C) is preferably 30% by mass or more and 80% by mass or less, more preferably 35% by mass or more and 70% by mass or less, and even more preferably 40% by mass or more and 65% by mass or less.

[0116] In the spraying method of the present invention, the dispersant for the sprayable hydraulic composition can be used by mixing it with water in advance during the process of preparing the sprayable hydraulic composition. In the spraying method of the present invention, the dispersant for the sprayable hydraulic composition is mixed with the hydraulic powder in the sprayable hydraulic composition in an amount of preferably 0.3% by mass or more, more preferably 0.4% by mass or more, even more preferably 0.5% by mass or more, from the viewpoint of moldability of the hydraulic composition and suppression of nozzle clogging, and preferably 2.0% by mass or less, more preferably 1.5% by mass or less, even more preferably 1.0% by mass or less, from the viewpoint of moldability and strength development of the hydraulic composition. Alternatively, in the spraying method of the present invention, the dispersant for the sprayable hydraulic composition is mixed with the hydraulic powder in the sprayable hydraulic composition in an amount preferably 0.3% to 2.0% by mass, more preferably 0.4% to 1.5% by mass, and even more preferably 0.5% to 1.0% by mass, from the viewpoint of moldability of the hydraulic composition, suppression of nozzle clogging, and strength development.

[0117] In the present invention, the mixing of the dispersant for the sprayable hydraulic composition of the present invention, hydraulic powder, aggregate, water, and other optional components can be carried out by known methods. For example, a method of simultaneously mixing the hydraulic powder, water, and aggregate can be used. A mixing mixer such as a pan-type forced mixer, a twin-screw forced mixer, or a tiltable mixer can be used to mix these components.

[0118] In the present invention, a quick-setting agent can be optionally mixed into a hydraulic composition for spraying, which is obtained by mixing hydraulic powder, aggregate, and water. The mixing of the hydraulic composition for spraying and the quick-setting agent can be carried out, for example, by a general spraying method in which the hydraulic composition for spraying and the quick-setting agent are fed under air pressure and mixed together.

[0119] When a rapid-setting agent is used in the spraying method of the present invention, the rapid-setting agent is mixed with the hydraulic powder in the spraying hydraulic composition in an amount preferably of 0.1% by mass or more, more preferably of 0.2% by mass or more, even more preferably of 0.5% by mass or more, and preferably 15% by mass or less, more preferably 12% by mass or less, and even more preferably 10% by mass or less, from the viewpoint of moldability, strength development, and nozzle clogging suppression of the hydraulic composition. Alternatively, when a rapid-setting agent is used in the spraying method of the present invention, the rapid-setting agent is mixed with the hydraulic powder in the spraying hydraulic composition in an amount preferably of 0.1% by mass or more and 15% by mass or less, more preferably of 0.2% by mass or more and 12% by mass or less, and even more preferably 0.5% by mass or more and 10% by mass or less, from the same viewpoint.

[0120] In the spraying method of the present invention, the sprayable hydraulic composition prepared in this manner is sprayed onto the target object. The spraying method of the present invention can be carried out using conventional spraying equipment. The spraying equipment only needs to be able to perform spraying without any problems. For example, it is possible to use a product such as "Arriba 280" manufactured by Arriba Corporation for pumping the sprayable hydraulic composition, and a product such as "Natomcrete" manufactured by Chiyoda Seisakusho for pumping the rapid setting agent, mix the two to prepare the sprayable hydraulic composition, and then spray it.

[0121] <Use as a dispersant for spray-applied hydraulic compositions> In exemplary embodiments, the present invention provides the use of a copolymer (A) having a monomer-derived constituent unit (I) represented by the general formula (A1) and a monomer-derived constituent unit (II) represented by the general formula (A2) as a dispersant for spray-applied hydraulic compositions.

[0122] In using the present invention, the provisions described in the dispersant for sprayable hydraulic compositions and its manufacturing method, the sprayable hydraulic composition and its manufacturing method, and the spraying method of the present invention can be applied as appropriate. In using the present invention, the preferred embodiment of copolymer (A) is the same as the preferred embodiment of copolymer (A) in the dispersant for sprayable hydraulic compositions of the present invention described above. In using the present invention, copolymer (A) can be used in combination with any component such as component (B) described in the dispersant for sprayable hydraulic compositions of the present invention described above. Furthermore, the preferred embodiment of the sprayable hydraulic composition in which copolymer (A) is used as a dispersant for sprayable hydraulic compositions, for example, the preferred embodiment of hydraulic powder and water, is the same as the preferred embodiment of hydraulic powder and water in the sprayable hydraulic composition of the present invention. Furthermore, in using the present invention, an example of the embodiment of copolymer (A) is the embodiment in which a dispersant for sprayable hydraulic compositions containing copolymer (A) in the amount described in the dispersant for sprayable hydraulic compositions of the present invention is used in the amount described in the sprayable hydraulic composition of the present invention. The same applies to the usage of optional components such as component (B) described in the dispersant for spray-applied water-hardening compositions of the present invention.

[0123] The following are examples of aspects of the present invention. These aspects can be appropriately applied to the dispersant for sprayable hydraulic compositions, the sprayable hydraulic compositions, the method for producing sprayable hydraulic compositions, the spraying method, and the use of the present invention as a dispersant for sprayable hydraulic compositions.

[0124] <1> A dispersant for sprayable hydraulic compositions, comprising a copolymer (A) having a monomer-derived constituent unit (I) represented by the following general formula (A1), and a monomer-derived constituent unit (II) represented by the following general formula (A2). [In the formula, R １ａ This represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ This represents a hydrogen atom, alkali metal, alkaline earth metal (half atom), ammonium, or organic ammonium. [In the formula, R ２ａ X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １represents an alkylene group or carbonyl group having 1 to 4 carbon atoms. AO represents an alkylene oxy group having 2 or 3 carbon atoms. n1 is the average number of moles of AO added, and is a number of 100 or more. R ３ａ This represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.

[0125] <2> The dispersant for sprayable hydraulic compositions according to <1>, wherein the weight-average molecular weight of the copolymer (A) is 5,000 or more and 200,000 or less.

[0126] <3> The dispersant for sprayable hydraulic compositions according to <1> or <2> above, wherein the number average molecular weight of the copolymer (A) is 5,000 or more and 200,000 or less.

[0127] <4> A dispersant for a sprayable hydraulic composition according to any one of <1> to <3> above, wherein the molar ratio [(I) / (II)] of the constituent unit (I) to the constituent unit (II) in the copolymer (A) is 0.5 or more and 30 or less.

[0128] <5> A dispersant for a sprayable hydraulic composition according to any one of <1> to <4> above, wherein the polydispersity of the copolymer (A) is 1.02 or more and 10 or less.

[0129] <6> A dispersant for a sprayable hydraulic composition according to any one of <1> to <5> above, wherein the copolymer (A) has a constituent unit (III) derived from a monomer represented by the following general formula (A3). [In the formula, R ４ａ X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ２ represents an alkylene group or carbonyl group having 1 to 4 carbon atoms. AO represents an alkylene oxy group having 2 or 3 carbon atoms. n2 is the average number of moles of AO added, and represents a number between 5 and 100. R ５ａ This represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0130] <7> The dispersant for a sprayable hydraulic composition according to <6> above, wherein the copolymer (A) has a constituent unit (III) derived from the monomer represented by the general formula (A3), and the molar ratio of the constituent unit (II) to the constituent unit (III) [(II) / (III)] in the copolymer (A) is 0.05 or more and 100 or less.

[0131] <8> A dispersant for a sprayable hydraulic composition according to <6> or <7> above, wherein the average number of moles of AO added to constituent unit (II) and constituent unit (III), as shown in the following formula (1), is 10 or more and 200 or less in the copolymer (A). Average number of moles of AO added to constituent unit (II) and constituent unit (III) = [[Molar ratio of constituent unit (II)] ＩＩ ×n1] + [Molar ratio of constituent units (III)] ＩＩＩ ×n2〕〕 / 〔[Molar ratio of constituent unit (II) ＩＩ ] + [molar ratio of constituent units (III)] ＩＩＩ 〕〕 (1) [In equation (1), molar ratio ＩＩ This is the molar ratio of constituent unit (II) to all constituent units of copolymer (A), and the molar ratio ＩＩＩ n1 is the molar ratio of constituent unit (III) to all constituent units of copolymer (A), n1 is the average number of moles of AO added in general formula (A2), and n2 is the average number of moles of AO added in general formula (A3).

[0132] <9> The dispersant for spray-type hydraulic compositions according to any one of <1> to <8> above, wherein the copolymer (A) is contained in an amount of 10% by mass or more and 60% by mass or less in the dispersant for spray-type hydraulic compositions.

[0133] <10> A dispersant for a sprayable hydraulic composition according to any one of <1> to <9> above, which contains water in an amount of 40% by mass or more and 85% by mass or less.

[0134] <11> A sprayable hydraulic composition containing a dispersant for sprayable hydraulic compositions described in any of <1> to <10> above.

[0135] <12> The sprayable hydraulic composition according to <11> above, comprising water and hydraulic powder, wherein the water / hydraulic powder ratio (W / C) is 30% by mass or more and 80% by mass or less.

[0136] <13> The sprayable hydraulic composition according to <11> or <12> above, which contains 0.04% by mass or more and 0.4% by mass or less of the dispersant.

[0137] <14> A sprayable hydraulic composition according to any one of <11> to <13>, further comprising an aluminosilicate.

[0138] <15> A sprayable hydraulic composition according to any one of <11> to <14> above, further containing a water-soluble polymer [excluding those corresponding to copolymer (A)].

[0139] <16> A sprayable hydraulic composition according to any of <11> to <15>, further comprising a rapid setting agent.

[0140] <17> The sprayable hydraulic composition according to <16> above, wherein the rapid setting agent comprises one or more selected from cement mineral-based rapid setting agents and aluminum-based rapid setting agents.

[0141] <18> A sprayable hydraulic composition according to any one of <11> to <17> above, further comprising (B) a water-soluble polymer [excluding those corresponding to copolymer (A)], wherein component (B) is one or more selected from polyethylene oxide, polymers containing monomer-derived units including a carboxyl group or a salt thereof, and cellulosic polymers.

[0142] <19> The sprayable hydraulic composition according to <18> above, wherein component (B) is polyethylene oxide and its weight-average molecular weight is 200,000 or more and 10,000,000 or less.

[0143] <20> The sprayable hydraulic composition according to <18> above, wherein component (B) is carboxymethylcellulose or a salt thereof, and its degree of etherification is 0.5 or more and 1.5 or less.

[0144] <21> A method for producing a sprayable hydraulic composition, comprising mixing a dispersant for sprayable hydraulic compositions described in any of <1> to <10> above with a hydraulic powder.

[0145] <22> A spraying method comprising mixing a hydraulic composition containing hydraulic powder and water with a dispersant for spraying hydraulic compositions described in any of <1> to <10> above and spraying the mixture onto an object.

[0146] <23> Use of a copolymer (A) having monomer-derived constituent units (I) represented by the following general formula (A1) and monomer-derived constituent units (II) represented by the following general formula (A2) as a dispersant for sprayable hydraulic compositions. [In the formula, R １ａ This represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ This represents a hydrogen atom, alkali metal, alkaline earth metal (half atom), ammonium, or organic ammonium. [In the formula, R ２ａ X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ represents an alkylene group or carbonyl group having 1 to 4 carbon atoms. AO represents an alkylene oxy group having 2 or 3 carbon atoms. n1 is the average number of moles of AO added, and is a number of 100 or more. R ３ａ This represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.

[0147] In the examples and comparative examples, the dispersants for sprayable hydraulic compositions shown in Table 2 were used. The shape retention, strength development, and nozzle clogging of the sprayable hydraulic compositions containing the dispersants were then evaluated. Details of each component shown in the table are described below.

[0148] <Copolymer (A)> ・A-1: Methacrylic acid / MPEG (average number of moles of ethylene glycol added: 120) ester = 95 / 5 (mol%) ・A-2: Methacrylic acid / MPEG (average number of moles of ethylene glycol added: 120) ester = 90 / 10 (mol%) ・A-3: Methacrylic acid / MPEG (average number of moles of ethylene glycol added: 120) ester = 80 / 20 (mol%) ・A-4: Methacrylic acid / MPEG (average number of moles of ethylene glycol added: 120) ester = 65 / 35 (mol%) ・A-5: Methacrylic acid / MPEG (average number of moles of ethylene glycol added: 120) ester / MPEG (average number of moles of ethylene glycol added: 23) ester = 68.9 / 26.7 / 4.4 (mol%) Note that MPEG, which is the monomer constituting copolymer (A) and copolymer (A'), is ω-methoxypolyethylene glycol monomethacrylate.

[0149] <Copolymer (A')> ・A'-1: Methacrylic acid / MPEG (average number of moles of ethylene glycol added: 23) ester = 73 / 27 (mol%) ・A'-2: Acrylic acid / TPEG (average number of moles of ethylene glycol added: 71) ester = 76 / 24 (mol%) ・A'-3: Acrylic acid / TPEG (average number of moles of ethylene glycol added: 60) ester = 84 / 16 (mol%) Note that TPEG, the monomer constituting copolymer (A'), is polyethylene glycol isoprenyl ether.

[0150] (Manufacturing Example) Copolymer A-1 was manufactured as follows: 114 g of water was placed in a glass reaction vessel (four-necked flask) equipped with a mixer, and while stirring, nitrogen was purged and the temperature was raised to 80°C in a nitrogen atmosphere. 25.4 g of methacrylic acid (reagent: manufactured by Wako Pure Chemical Industries, Ltd.), 139.5 g of an aqueous solution of 60% by mass ω-methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 120; ester purity: 100% by mass), and 1.2 g of 3-mercaptopropionic acid were mixed and dissolved in an aqueous solution, and an aqueous solution of 1.9 g of ammonium persulfate dissolved in 45 g of water was added dropwise to the reaction vessel over 1.5 hours. After that, the mixture was aged at 80°C for 1 hour, and then an aqueous solution of 0.8 g of ammonium persulfate dissolved in 15 g of water was added dropwise over 30 minutes, and the mixture was continued to be aged at 80°C for 1.5 hours. After maturation, the mixture was cooled to below 40°C to obtain copolymer A-1 with a weight-average molecular weight of 37,000. The mass ratio of A1 / A2 in copolymer A-1, i.e., methacrylic acid / ω-methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 120), was 13.3 / 43.7 [95 / 5 (molar ratio)]. The mixing ratio (molar ratio) of monomer (A1) and monomer (A2) used in the production of copolymer A-1 can be considered as the molar ratio [(I) / (II)] of constituent units (I) derived from monomer (A1) and constituent units (II) derived from monomer (A2) in copolymer A-1. The same applies to the other copolymers A-2 to A-5 and copolymers A'-1 to A'-3. Copolymers (A) and (A') of the examples and comparative examples shown in Table 2 were produced according to the above method.

[0151] <Method for Measuring Weight-Average Molecular Weight (Mw) and Number-Average Molecular Weight (Mn) of Copolymer (A)>The weight-average molecular weight of copolymer (A) was measured by the GPC method under the conditions of a high-speed GPC device (HLC-8320GPC, manufactured by Tosoh Corporation), detector: RI, column: G4000PWXL + G2500PWXL (anion), mobile phase: 0.2 M phosphate buffer / acetonitrile = 9 / 1, flow rate: 1.0 mL / min., column temperature: 40 °C, and standard substance: polyethylene glycol. The weight-average molecular weight (Mw) of copolymer (A) was calculated from the area of the first peak with a peak present at a retention time of 13 minutes to 17 minutes. Also, the number-average molecular weight (Mn) of copolymer (A) was calculated from the area of the first peak with a peak present at a retention time of 13 minutes to 17 minutes.

[0152] <Component (B)>- B-1: Polyethylene oxide (Alcox E-30, manufactured by Meisei Chemical Industry Co., Ltd.) - B-2: Sodium carboxymethyl cellulose (No. 1160, manufactured by Daicel Miraiz Co., Ltd.), degree of etherification 0.68, average particle diameter 89 μm, weight-average molecular weight 1,096,000, viscosity of 1 mass% aqueous solution (25 °C) 200 mPa·s - B-3: Hydroxypropylmethyl cellulose (Ascaclean D, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0153] <Components of Bentonite A>- Purified montmorillonite: Kunipia F, manufactured by Kunimine Industries Co., Ltd. - Quartz: manufactured by Sigma-Aldrich, average particle diameter 63.6 μm, crystallinity 100% - Aluminum silicate: Synthetic aluminum silicate (82% by mass SiO ２ , 9.5% by mass Al ２ O ３ , 8% by mass Na ２O) Sigma-Aldrich, swelling degree 7 mL / 2 g, average particle size 17.9 μm Kaolin: Kaolin, Hayashi Pure Chemical Industries, Ltd., average particle size 6.3 μm Zeolite K: Synthetic zeolite, HS-500, powder, potassium L, Fujifilm Wako Chemical Co., Ltd., swelling degree 3 mL / 2 g, average particle size 25.9 μm Synthetic mica: Synthetic mica, non-swelling, Fujifilm Wako Pure Chemical Corporation, swelling degree 3 mL / 2 g, average particle size 6.5 μm Calcium carbonate: Calcium carbonate CP, Sigma-Aldrich, average particle size 58.4 μm Talc: Fujifilm Wako Pure Chemical Corporation, average particle size 55.8 μm, average aspect ratio 1.33

[0154] <Method for preparing Bentonite A> 60 g of purified montmorillonite, 20 g of quartz, 3.75 g of aluminum silicate, 3.75 g of kaolin, 3.75 g of zeolite K, 3.75 g of synthetic mica, 3 g of calcium carbonate, and 2 g of talc were placed in a 250 mL bottle. The bottle was sealed with a lid and shaken for 10 minutes to prepare Bentonite A.

[0155] <Method for preparing liquid rapid setting agent> (1) Rapid setting agent A 500 g of aluminum sulfate 14-18 hydrate (manufactured by Kanto Chemical Co., Ltd.) was added to a 2 L cup, and then water was added until the total volume reached 1,000 g. The mixture was mixed and dissolved to prepare rapid setting agent A containing 27% by mass of aluminum sulfate. (2) Rapid setting agent B 59.13 g of aluminum sulfate 14-18 hydrate (manufactured by Kanto Chemical Co., Ltd.) and 27.67 g of water were added to a 300 mL disposable cup, and the mixture was stirred at 100 rpm (EUROSTAR200 control, manufactured by IKA Japan Co., Ltd.) at 20°C for 1 hour using a flat 6-blade paddle blade (FP-50, manufactured by AS ONE Corporation). Subsequently, 6 g of aluminum hydroxide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 3 g of bentonite A, 1.4 g of formic acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.6 g of phosphoric acid (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.5 g of diethanolamine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.5 g of 2,2'-methyliminodiethanol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), 0.2 g of ammonium fluoride (manufactured by Sigma-Aldrich), and 1.0 g of colloidal silica (ASP-350, manufactured by JGC Catalysts & Chemicals Inc.) were added, and the mixture was stirred at 100 rpm at 20°C for 1 hour using a flat 6-blade paddle to prepare rapid setting agent B. Rapid setting agent B is a rapid setting agent containing the aluminosilicate of component (C).

[0156] <Method for Evaluating Shape Retention> (1) Preparation of Hydraulic Composition for Spraying A mortar mixer specified in "JIS R 5201 Physical Testing Methods for Cement" was used to prepare the hydraulic composition for spraying. The following water, cement, and fine aggregate were used to prepare the hydraulic composition for spraying. Water (W): Wakayama City tap water Cement (C): Ordinary Portland cement (two-component mixture: Taiheiyo Cement / Sumitomo Osaka Cement = 1 / 1, mass ratio), density 3.16 g / cm³ ３ Fine aggregate (S): Joyo mountain sand, density 2.55g / cm ３

[0157] 400 g of cement and 679 g of fine aggregate (sifted to 1 mm or less) were added to a 500 mL disposable cup. Using a hand mixer (MK-H4, manufactured by Panasonic Corporation), the mixture was dry-mixed for 10 seconds at setting 1. Then, 192 g of water was added and the mixture was stirred for 60 seconds at setting 3 using the same hand mixer to prepare a sprayable hydraulic composition. The dispersant for the sprayable hydraulic composition was prepared by pre-mixing a dispersant containing 25% by mass of copolymer (A) or copolymer (A') from Table 2 or Table 3 with water. The amount of dispersant used for the sprayable hydraulic composition was 0.8% by mass relative to the cement (C).

[0158] (2) Method for evaluating shape retention The shape retention of the sprayable hydraulic composition prepared in (1) was evaluated based on the vane shear resistance value of the sprayable hydraulic composition. Specifically, using a direct-reading torque driver (manufactured by Tohnichi Manufacturing Co., Ltd.), the vane shear resistance value of the sprayable hydraulic composition was measured at predetermined time intervals, with the time at which mixing began after adding 36 g of rapid setting agent A or rapid setting agent B to 1271 g of the hydraulic composition prepared in (1) set as 0 seconds. A vane measuring 20 mm x 40 mm was used. Tables 2 and 3 show the vane shear resistance values ​​for each hydraulic composition after 0.5 minutes, 1 minute, 2 minutes, and 3 minutes. The higher the vane shear resistance value, the higher the shape retention of the hydraulic composition, meaning that the shape is less likely to collapse after molding, and it is a dispersant for sprayable hydraulic compositions with good moldability. In the preparation of the hydraulic composition shown in Table 3, (B) water-soluble polymer was added in powder form along with the cement and fine aggregate described in (1) above.

[0159] Table 2 shows that by including the dispersant for sprayable hydraulic compositions of the present invention, a sprayable hydraulic composition with a high vane shear resistance value 3 minutes after mixing with a rapid setting agent was obtained. This sprayable hydraulic composition exhibited good moldability immediately after spraying when used as a sprayable hydraulic composition, and was a hydraulic composition that did not easily lose its shape after molding.

[0160]

[0161] (Notes) *1: In Tables 2 and 3, monomer (A1) is the monomer from which constituent unit (I) is derived, and monomer (A2) is the monomer from which constituent unit (II) is derived. *2: In Tables 2 and 3, MPEG of monomer (A2) is ω-methoxypolyethylene glycol monomethacrylate, and TPEG is polyethylene glycol isoprenyl ether. The number in parentheses for monomer (A2) represents the average number of moles of ethylene oxide added. *3: In Tables 2 to 6, the amount (% × C) of the dispersant and quick-setting agent for sprayable hydraulic compositions is the actual mass relative to the cement (C) contained in the sprayable hydraulic composition. *4: This is the molar ratio (A1 / A2) of monomer (A1) and monomer (A2) used in the synthesis of copolymer (A) or copolymer (A'). *5: In Table 3, (B) the amount of water-soluble polymer (% × C) is the actual mass relative to the cement (C) contained in the sprayable hydraulic composition.

[0162] Table 3 shows that by further including (B) a water-soluble polymer, a sprayable hydraulic composition with an even higher vane shear resistance value 3 minutes after mixing with a rapid-setting agent was obtained. This sprayable hydraulic composition exhibited good moldability immediately after spraying when used as a sprayable hydraulic composition, and was a hydraulic composition that did not easily lose its shape after molding.

[0163]

[0164] <Method for evaluating strength development> Strength development is evaluated using the Proctor penetration resistance test (cross-sectional area of ​​the penetration needle: 50 mm²) according to JIS A 6204. ２The strength was measured using the following method. 400 g of cement and 1053 g of fine aggregate were added to the mixing bowl of a mortar mixer (Hobart type mixer, manufactured by Kansai Kiki Seisakusho Co., Ltd., KC-8), and dry-mixed for 10 seconds. Then, 240 g of water was added and stirred at low speed (stirring speed: orbital 62 rpm, rotational 141 rpm) for 2 minutes. The dispersant for the sprayable hydraulic composition contained a total of 25% by mass of the copolymer (A) mixture described in Table 4 or Table 5, and was used after being mixed with water beforehand. The dispersant for the sprayable hydraulic composition was used in the amount of the dispersant described in Table 4 or Table 5 relative to the cement (C). Liquid quick-setting agent A was added to the prepared mortar in the amount described in Table 4, and stirred at high speed (rotational 285 ± 10 rpm, orbital 125 ± 10 rpm) for 7 seconds. Mortar was placed in a square silicone tray (TRUSCO Nakayama Co., Ltd., SLTS-105105) and the surface was smoothed with a trowel. The penetration resistance was measured 3 hours after adding the rapid setting agent A. The results are shown in Table 4. In addition, 20 g of powdered rapid setting agent (Taiheiyo Shot Master, Taiheiyo Material Co., Ltd.) was added to the prepared mortar, and the penetration resistance was measured at the elapsed time intervals shown in Table 5, in the same manner as above. The results are shown in Table 5. The higher the penetration resistance, the better the strength development of the dispersant for hydraulic compositions.

[0165]

[0166]

[0167] <Method for evaluating nozzle clogging> (1) Preparation of sprayable hydraulic composition 192 g of water, 400 g of cement, and 846 g of fine aggregate were added to the mixing bowl of a mortar mixer and stirred at low speed (stirring speed: orbital 62 rpm, rotational 141 rpm) for 20 minutes. 190 g of coarse aggregate (10 mm or less, crushed stone from Ieshima) was added to the obtained mortar and mixed by hand for 20 seconds. The dispersant for the sprayable hydraulic composition contained a total of 25% by mass of the copolymer (A) mixture shown in Table 6, and was used after being mixed with water beforehand. The amount of dispersant for the sprayable hydraulic composition was such that the dispersant was 0.7% by mass relative to the cement (C). 1,500 g of the obtained sprayable hydraulic composition was mixed with liquid rapid setting agent A in the amount shown in Table 6 and mixed by hand for 5 seconds.

[0168] (2) Method for measuring nozzle sagging rate 1,500 g of the sprayable hydraulic composition obtained in (1) above was sprayed onto a wooden board 18 cm away from the discharge port of a powder and granular material conveying device (Breath Slider, model number K-40, manufactured by Breath Co., Ltd.). The pressure of the compressor connected to the powder and granular material conveying device was 0.6 MPa, and the diameter d of the discharge port was 3.5 cm. Some of the sprayed sprayable hydraulic composition was not atomized and fell directly below the discharge port. The nozzle sagging rate was calculated based on the following formula (2). A sprayable hydraulic composition with a low nozzle sagging rate is one in which the sprayable hydraulic composition is more atomized, and nozzle clogging is suppressed. Therefore, a dispersant for a sprayable hydraulic composition with a low nozzle sagging rate is a dispersant that can more effectively suppress nozzle clogging. Nozzle sag rate (mass %) = [(amount of sprayable hydraulic composition that fell straight down) / (mass of sprayed sprayable hydraulic composition)] × 100 (2)

[0169]

Claims

1. A dispersant for sprayable hydraulic compositions, comprising a copolymer (A) having a monomer-derived constituent unit (I) represented by the following general formula (A1), and a monomer-derived constituent unit (II) represented by the following general formula (A2). [In the formula, R １ａ This represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ This represents a hydrogen atom, alkali metal, alkaline earth metal (half atom), ammonium, or organic ammonium. [In the formula, R ２ａ X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ represents an alkylene group or carbonyl group having 1 to 4 carbon atoms. AO represents an alkylene oxy group having 2 or 3 carbon atoms. n1 is the average number of moles of AO added, and is a number of 100 or more. R ３ａ This represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.

2. The dispersant for a sprayable hydraulic composition according to claim 1, wherein the weight-average molecular weight of the copolymer (A) is 5,000 or more and 200,000 or less.

3. The dispersant for a sprayable hydraulic composition according to claim 1 or 2, wherein the molar ratio [(I) / (II)] of the constituent unit (I) to the constituent unit (II) in the copolymer (A) is 0.5 or more and 30 or less.

4. The dispersant for a sprayable hydraulic composition according to any one of claims 1 to 3, wherein the polydispersity of the copolymer (A) is 1.02 or more and 10 or less.

5. The dispersant for a sprayable hydraulic composition according to any one of claims 1 to 4, wherein the copolymer (A) has a constituent unit (III) derived from a monomer represented by the following general formula (A3), and the molar ratio of the constituent unit (II) to the constituent unit (III) in the copolymer (A) is 0.05 or more and 100 or less [(II) / (III)]. [In the formula, R ４ａ X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. ２ represents an alkylene group or carbonyl group having 1 to 4 carbon atoms. AO represents an alkylene oxy group having 2 or 3 carbon atoms. n2 is the average number of moles of AO added, and represents a number between 5 and 100. R ５ａ This represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

6. In the copolymer (A), the average number of moles of AO added to the structural unit (II) and the structural unit (III) represented by the following formula (1) is 10 or more and 200 or less. The dispersant for a sprayable hydraulic composition according to claim 5. Average number of moles of AO added to the structural unit (II) and the structural unit (III) = [〔Molar ratio of the structural unit (II) ＩＩ ×n1〕+〔Molar ratio of the structural unit (III) ＩＩＩ ×n2〕] / [〔Molar ratio of the structural unit (II) ＩＩ 〕+〔Molar ratio of the structural unit (III) ＩＩＩ 〕] (1) [In the formula (1), the molar ratio ＩＩ is the molar ratio of the structural unit (II) to all the structural units constituting the copolymer (A), and the molar ratio ＩＩＩ is the molar ratio of the structural unit (III) to all the structural units constituting the copolymer (A), n1 is the average number of moles of AO added in the general formula (A2), and n2 is the average number of moles of AO added in the general formula (A3).]] 7. A sprayable hydraulic composition containing the dispersant for sprayable hydraulic compositions described in any one of claims 1 to 6.

8. The sprayable hydraulic composition according to claim 7, comprising 0.04% by mass or more and 0.4% by mass or less of the dispersant.

9. The sprayable hydraulic composition according to claim 7 or 8, further comprising an aluminosilicate.

10. A sprayable hydraulic composition according to any one of claims 7 to 9, comprising a water-soluble polymer [excluding those corresponding to copolymer (A)].

11. A sprayable hydraulic composition according to any one of claims 7 to 10, comprising a rapid setting agent.

12. A method for producing a sprayable hydraulic composition, comprising mixing a dispersant for sprayable hydraulic compositions according to any one of claims 1 to 6 with a hydraulic powder.

13. A spraying method comprising mixing a hydraulic composition containing hydraulic powder and water with a dispersant for spraying hydraulic compositions according to any one of claims 1 to 6 and spraying the mixture onto an object.

14. Use of a copolymer (A) having monomer-derived constituent units (I) represented by the following general formula (A1) and monomer-derived constituent units (II) represented by the following general formula (A2) as a dispersant for sprayable hydraulic compositions. [In the formula, R １ａ This represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ This represents a hydrogen atom, alkali metal, alkaline earth metal (half atom), ammonium, or organic ammonium. [In the formula, R ２ａ X represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. １ represents an alkylene group or carbonyl group having 1 to 4 carbon atoms. AO represents an alkylene oxy group having 2 or 3 carbon atoms. n1 is the average number of moles of AO added, and is a number of 100 or more. R ３ａ This represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.

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