Hydraulic composition, hardened product, and method for producing hydraulic composition

Abstract

To provide a hydraulic composition capable of producing a cured matter having sufficient strength and low water absorptivity.SOLUTION: A hydraulic composition comprises: (A) cement; (B) polyalcohol being an optional component; (C) polyvalent isocyanate; and (D) a urethane compound including residue of the polyalcohol and residue of the polyvalent isocyanate. When the hydraulic composition comprises the (B) component, the (B) component includes the polyalcohol included in the (D) component as the residue and the (C) component includes the polyvalent isocyanate included in the (D) component as the residue, and the total amount of the (B) to (D) components satisfies at least one of the following conditions (1) and (2): (1) being 18 pts.mass or lower relative to 100 pts.mass of the (A) component; and (2) being 4.15 mass% or lower relative to 100 mass% of the total amount of the hydraulic composition.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a hydraulic composition, a hardened product, and a method for producing a hydraulic composition.

Background Art

[0002] Conventionally, for the purpose of preventing deterioration of the structure due to water intrusion and leakage into the interior on the surface of building and civil engineering structures made of concrete, methods such as coating with polymer cement, coating with a siliceous waterproofing agent-containing mortar, and injection / permeation / film coating methods using organic resins, cement-based materials, and water glass-based materials have been proposed.

[0003] For example, in the technique described in Patent Document 1, an adhesive such as a urethane resin is thinly applied on a resin film waterproof layer (urethane waterproof layer) containing a urethane resin, and an EVA (ethylene vinyl acetate copolymer) - based thermoplastic resin sheet is spread. The floor slab waterproof structure using a urethane waterproof layer has a structure in which a primer resin layer, a urethane waterproof layer, a urethane resin adhesive layer, and an EVA-based thermoplastic resin sheet are sequentially laminated. For the floor slab waterproof structure having such a configuration, after forming the primer resin layer and the urethane waterproof layer, the main agent / hardener (isocyanate / polyol) of the urethane resin adhesive is mixed at the construction site, thinly and uniformly applied with a roller brush or the like, and the thermoplastic resin sheet is leveled for construction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, cement-based hardened bodies obtained by curing conventional polymer cements and the like have a problem that their strength is not sufficient and their water absorption is high, so they are liable to deteriorate due to underwater fatigue.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a hydraulic composition capable of obtaining a cured product having sufficient strength and low water absorption. Another object of the present invention is also to provide a cured product of such a hydraulic composition and a method for producing the hydraulic composition.

Means for Solving the Problems

[0007] The hydraulic composition of the present invention contains (A) cement, (B) a polyhydric alcohol which is an optional component, (C) a polyvalent isocyanate, and (D) a urethane compound containing residues of the polyhydric alcohol and residues of the polyvalent isocyanate. When the hydraulic composition contains the component (B), the component (B) contains a polyhydric alcohol contained as a residue in the component (D), the component (C) contains a polyvalent isocyanate contained as a residue in the component (D), and the total amount of the components (B) to (D) satisfies at least one of the following conditions (1) and (2): a hydraulic composition. (1) It is 18 parts by mass or less with respect to 100 parts by mass of the component (A). (2) It is 4.15% by mass or less with respect to 100% by mass of the total amount of the hydraulic composition.

[0008] It is preferable that the component (B) contains (B1) an ethylene oxide adduct or a propylene oxide adduct of a dihydric alcohol.

[0009] It is preferable that the component (B1) is an ethylene oxide adduct of polypropylene oxide.

[0010] It is preferable that the component (B) contains (B2) a short-chain dihydric alcohol having a molecular weight of 200 or less.

[0011] It is preferable that the component (B) contains (B3) an ethylene oxide adduct or a propylene oxide adduct of an alcohol having three or more valences.

[0012] It is preferable that the hydraulic composition further contains an aggregate.

[0013] It is preferable that the above hydraulic composition further contains water.

[0014] The cured product of the present invention is the cured product of the hydraulic composition described above.

[0015] The method for producing the hydraulic composition of the present invention includes a step of heating a mixture of a polyhydric alcohol and a polyvalent isocyanate to obtain a partial polymer containing a urethane compound, and a step of (A) mixing cement and the partial polymer to obtain a hydraulic composition, wherein the total amount of the polyhydric alcohol, the polyvalent isocyanate, and the urethane compound in the hydraulic composition satisfies at least one of the following conditions (1) and (2). (1) It is 18 parts by mass or less with respect to 100 parts by mass of the component (A). (2) It is 4.15% by mass or less with respect to 100% by mass of the total amount of the hydraulic composition.

Advantages of the Invention

[0016] According to the present invention, it is possible to provide a hydraulic composition capable of obtaining a cured product having sufficient strength and low water absorption. Further, according to the present invention, it is also possible to provide a cured product of such a hydraulic composition and a method for producing the hydraulic composition.

Modes for Carrying Out the Invention

[0017] The hydraulic composition of the present embodiment is a hydraulic composition containing (A) cement, (B) a polyhydric alcohol as an optional component, (C) a polyvalent isocyanate, and (D) a urethane compound containing residues of the polyhydric alcohol and residues of the polyvalent isocyanate. When the hydraulic composition contains the component (B), the component (B) contains a polyhydric alcohol contained as a residue in the component (D), the component (C) contains a polyvalent isocyanate contained as a residue in the component (D), and the total amount of the components (B) to (D) satisfies at least one of the following conditions (1) and (2). (1) It is 18 parts by mass or less with respect to 100 parts by mass of the component (A). (2) It is 4.15% by mass or less with respect to 100% by mass of the total amount of the hydraulic composition. According to such a hydraulic composition, a cured product having sufficient strength and low water absorption can be obtained.

[0018] Regarding condition (1), the total amount of components (B) to (D) is preferably 17 parts by mass or less, more preferably 16% by mass or less, and still more preferably 15% by mass or less with respect to 100 parts by mass of component (A). Even if the total amount of components (B) to (D) is very small, the above effects can be achieved. Therefore, there is no particular limitation as long as it is not 0 part by mass, but it is preferably 0.01 part by mass or more, more preferably 0.05 part by mass or more, and still more preferably 0.1 part by mass or more with respect to 100 parts by mass of component (A).

[0019] The hydraulic composition in condition (2) may contain the above components (B) to (D), water, and aggregate. Regarding condition (1), the total amount of components (B) to (D) is preferably 0.01 to 4.12% by mass with respect to 100% by mass of the total amount of the hydraulic composition.

[0020] [Cement] The hydraulic composition contains cement as component (A). The cement is not particularly limited, and one or more can be selected and used from Portland cements such as ordinary Portland cement, early-strength Portland cement, ultra-early-strength Portland cement, medium-heat Portland cement, low-heat Portland cement, sulfate-resistant Portland cement, etc.; mixed cements such as blast furnace cement, fly ash cement, silica fume cement, etc.; and other cements such as eco-cement, super-fast-hardening cement, alumina cement, phosphate cement, air-hardening cement, etc.

[0021] [Polyhydric alcohol] The hydraulic composition may contain a polyhydric alcohol as component (B). A polyhydric alcohol is a compound having two or more hydroxyl groups in the molecule. As component (B), there is no particular limitation as long as it is a compound having a plurality of hydroxyl groups in the molecule, and examples thereof include aliphatic polyhydric alcohols (hydrocarbon compounds in which a plurality of hydrogen atoms are substituted with hydroxyl groups), polyether polyols, polyester polyols, castor oil or its derivatives, polybutadiene-based polyols, alkanolamines, and the like. The number of hydroxyl groups contained in one molecule of the polyhydric alcohol may be 2 to 6, may be 2 to 5, may be 2 to 3, or may be 2. Note that the number of hydroxyl groups may be the average value (number average) per molecule, and in that case, the number may be a rational number.

[0022] The polyhydric alcohol preferably contains at least one compound selected from the following (B1) to (B3). (B1) contains an ethylene oxide adduct or a propylene oxide adduct of a dihydric alcohol. (B2) A dihydric alcohol having a molecular weight of 200 or less (hereinafter also referred to as a short-chain dihydric alcohol). (B3) An ethylene oxide adduct or a propylene oxide adduct of an alcohol having a trivalent or higher valence.

[0023] Component (B1) is a compound having a structure obtained by performing a ring-opening addition reaction of ethylene oxide or propylene oxide using a dihydric alcohol as an initiator, and as long as it is a compound having the same structure as the structure obtained by the ring-opening addition reaction, it does not have to be actually produced by ring-opening addition of ethylene oxide or propylene oxide.

[0024] From the viewpoint of the solubility of component (B1) in water, the number average molecular weight of component (B1) is preferably 300 to 3000, more preferably 400 to 2500, and even more preferably 500 to 2000.

[0025] Examples of the divalent alcohol include aliphatic dihydric alcohols (hydrocarbon compounds in which two hydrogen atoms are substituted with hydroxyl groups) such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol; polyalkylene glycols which are divalent alcohols such as polypropylene glycol (poly(1,2-propylene glycol) or polypropylene oxide) and polyethylene glycol. The divalent alcohol may be used alone or in combination of two or more.

[0026] (B1) component is preferably an ethylene oxide adduct of polypropylene glycol from the viewpoint of imparting hydrophilicity to the urethane compound described below. The mass ratio of ethylene oxide units to propylene oxide units (EO / PO mass ratio) in such an adduct is preferably from 10 / 90 to 90 / 10, more preferably from 15 / 85 to 80 / 20.

[0027] (B1) component includes Actocol ED28 (manufactured by Mitsui Chemicals SKC Polyurethane Co., Ltd.; number average molecular weight 4000, EO / PO mass ratio: 20 / 80), Actocol ED36 (manufactured by Mitsui Chemicals SKC Polyurethane Co., Ltd.; number average molecular weight 3600, EO / PO mass ratio: 78 / 22), Actocol ED56 (manufactured by Mitsui Chemicals SKC Polyurethane Co., Ltd.; number average molecular weight 2000), and the like.

[0028] (B2) component may have a molecular weight of 180 or less, or may have a molecular weight of 150 or less. Specific examples of (B2) component include aliphatic dihydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, and 1,6-hexanediol; and dialkylene glycols such as diethylene glycol and dipropylene glycol.

[0029] (Component (B3)) is a compound having a structure obtained by subjecting an alcohol having 3 or more valences as an initiator to a ring-opening addition reaction of ethylene oxide or propylene oxide. As long as it is a compound having the same structure as the structure obtained by the ring-opening addition reaction, it does not necessarily have to be actually produced by ring-opening addition of ethylene oxide or propylene oxide. It has the effect of reducing the water solubility of the urethane compound described later.

[0030] Examples of the alcohol having 3 or more valences include trivalent alcohols such as glycerin and trimethylolpropane, and alcohols having 3 or more valences such as pentaerythritol, dipentaerythritol, sorbitol, monosaccharides or polysaccharides (for example, sucrose). Among them, trivalent alcohols are preferred, and glycerin is more preferred. The trivalent alcohol may be used alone or in combination of two or more.

[0031] From the viewpoint of reducing the water absorption of the cured product formed from the hydraulic composition, the number average molecular weight (Mn) of component (B3) is preferably 300 to 7000, more preferably 500 to 6500, still more preferably 1000 to 6000, and particularly preferably 2000 to 6000.

[0032] Examples of component (B3) include EXCENOL 430 (Mn = 430), EXCENOL 1030 (Mn = 1000), EXCENOL 3030 (Mn = 3000), EXCENOL 4030 (Mn = 4000), EXCENOL 5030 (Mn = 5100) (all manufactured by AGC Inc.), etc.

[0033] [Polyvalent isocyanate] The hydraulic composition contains a polyisocyanate as component (C). The (C) polyisocyanate is not particularly limited as long as it has two or more isocyanate groups in the molecule. Specifically, the component (C) is an aromatic polyisocyanate such as phenylenediisocyanate, 1-methyl-2,4-phenylenediisocyanate, 1-methyl-2,6-phenylenediisocyanate, 1-methyl-2,5-phenylenediisocyanate, 1-methyl-3,5-phenylenediisocyanate, 1-ethyl-2,4-phenylenediisocyanate, 1-isopropyl-2,4-phenylenediisocyanate, 1,3-dimethyl-2,4-phenylenediisocyanate, 1,3-dimethyl-4,6-phenylenediisocyanate, 1,4-dimethyl-2,5-phenylenediisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1-methyl-naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, biphenyl-4,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, diphenylmethane-2,4-diisocyanate;Aliphatic or alicyclic polyisocyanates such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclopentylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-di(isocyanatomethyl)cyclohexane, 1,4-di(isocyanatomethyl)cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, 3,3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate, carbodiimide-modified isocyanate, polymethylene polyphenyl polyisocyanate, etc. These polyvalent isocyanates may be used alone or in combination of two or more. Among these, aromatic polyisocyanates are preferred from the viewpoints of mechanical strength and adhesiveness, aromatic diisocyanates are more preferred, and at least one of toluene diisocyanate (1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, and 1-methyl-2,5-phenylene diisocyanate) is even more preferred.;

[0034] [Urethane compound] The hydraulic composition contains a urethane compound as component (D). The urethane compound may be a urethane compound formed by a polymerization reaction (sequential polymerization) between the hydroxyl group of a polyhydric alcohol and the isocyanate group of a polyvalent isocyanate, and has a residue of the polyhydric alcohol and a residue of the polyvalent isocyanate. When component (B) is included in the hydraulic composition, the residue of the polyhydric alcohol is the residue of at least one of the polyhydric alcohols included as component (B). Also, the residue of the polyvalent isocyanate is the residue of at least one of the polyvalent isocyanates included as component (C) in the hydraulic composition. Component (D) contains a polyurethane compound (urethane prepolymer) having two or more urethane bonds in the molecule, and optionally may contain a monourethane compound having one urethane bond in the molecule. Note that the residue of the polyhydric alcohol and the residue of the polyvalent isocyanate respectively refer to the residue of the polyhydric alcohol and the residue of the polyvalent isocyanate when it is assumed that the urethane bond contained in the urethane compound is generated by the reaction between the hydroxyl group and the isocyanate group, and the urethane bond is not included in any of the residues. Also, the polyhydric alcohol contained as a residue in component (D) is obtained by substituting the urethane bond bonded to the residue of the polyhydric alcohol in component (D) with a hydroxyl group, and the polyvalent isocyanate contained as a residue in component (D) is obtained by substituting the urethane bond bonded to the residue of the polyvalent isocyanate in component (D) with an isocyanate group.

[0035] Such a urethane compound may be contained, for example, in a partial polymer obtained by heating a mixture of a raw material polyhydric alcohol and a polyvalent isocyanate. In the partial polymer, not all of the polyvalent isocyanate contained in the above mixture has reacted completely, and in addition to the above urethane compound, a part of the raw material polyvalent isocyanate may be contained unreacted in the partial polymer. Note that a part of the raw material polyhydric alcohol may be reacted and contained as an unreacted substance in the partial polymer, or may not be completely reacted and contained in the partial polymer.

[0036] When a partial polymer is blended into a hydraulic composition, at least one of a polyhydric alcohol and a polyvalent isocyanate may be additionally added to the hydraulic composition. The polyhydric alcohol and the polyvalent isocyanate to be additionally added may be compounds of the same type or different types from the polyhydric alcohol and the polyvalent isocyanate which are raw materials of the above urethane compound. That is, the unreacted polyhydric alcohol contained in the partial polymer and the polyhydric alcohol optionally additionally added are the component (B), and the unreacted polyvalent isocyanate contained in the partial polymer and the polyvalent isocyanate optionally additionally added are the component (C).

[0037] The total molar amount (represented as [OH]) of the hydroxyl groups contained in the polyhydric alcohol (B) contained in the hydraulic composition and the hydroxyl groups that the polyhydric alcohol contained as a residue in the urethane compound (D) has before reaction (that is, the hydroxyl groups that the polyhydric alcohol as a raw material has), and the total molar amount (represented as [NCO]) of the isocyanate groups contained in the polyvalent isocyanate (C) contained in the hydraulic composition and the isocyanate groups of the polyvalent isocyanate contained as a residue in the urethane compound (D) before reaction (that is, the isocyanate groups that the polyvalent isocyanate as a raw material has), the ratio [NCO] / [OH] is preferably greater than 1, more preferably 1.5 or more, and still more preferably 2 or more. When [NCO] / [OH] is greater than 1, a large amount of unreacted isocyanate groups are present in the hydraulic composition, so it is preferable because a large amount of the reaction between the isocyanate groups and water or polyhydric alcohol can be utilized as the cement hardens.

[0038] The (D) component preferably contains at least one residue of the above (B1), (B2) and (B3) components, and more preferably contains any residue of the above (B1), (B2) and (B3) components. The content of the (B1) component in the raw material of the (D) component is preferably 20 to 70% by mass, more preferably 30 to 60% by mass, based on 100% by mass of the total amount of the polyhydric alcohol used. The content of the (B2) component in the raw material of the (D) component is preferably 1 to 15% by mass, more preferably 3 to 10% by mass, based on 100% by mass of the total amount of the polyhydric alcohol used. The content of the (B3) component in the raw material of the (D) component is preferably 5 to 30% by mass, more preferably 10 to 25% by mass, based on 100% by mass of the total amount of the polyhydric alcohol used.

[0039] [Water] The hydraulic composition may contain water. The water is not particularly limited, and may be, for example, tap water, distilled water, deionized water, etc. The content of water in the hydraulic composition is preferably 20 to 100 parts by mass, more preferably 25 to 80 parts by mass, still more preferably 30 to 70 parts by mass, based on 100 parts by mass of the cement.

[0040] [Aggregate] The aggregate is not particularly limited, and may be fine aggregate, coarse aggregate, etc. The fine aggregate is not particularly limited, and may be silica sand, river sand, sea sand, mountain sand, crushed sand, fine aggregate of hard blast furnace slag, fine aggregate of blast furnace slag, fine aggregate of copper slag, fine aggregate of electric furnace oxidized slag, etc. The coarse aggregate is not particularly limited, and may be gravel, crushed stone, coarse aggregate of blast furnace slag, coarse aggregate of electric furnace oxidized slag, etc. The hydraulic composition may contain at least one of fine aggregate and coarse aggregate. Further, the hydraulic composition may contain two or more kinds of fine aggregate, and may contain two or more kinds of coarse aggregate. In addition, as defined in JIS A 0203:2014 "Concrete Terms", the fine aggregate is an aggregate that completely passes through a 10 mm sieve and passes through a 5 mm sieve by 85% or more by mass, and the coarse aggregate is an aggregate that remains on a 5 mm sieve by 85% or more by mass.

[0041] When the aggregate contains only fine aggregate, the content of the aggregate in the hydraulic composition is preferably 50 to 500 parts by mass, more preferably 100 to 400 parts by mass, and still more preferably 150 to 350 parts by mass with respect to 100 parts by mass of cement.

[0042] [Other Components] The hydraulic composition may contain other components (additives) such as gypsum, inorganic fine powder, thickener, defoaming agent, water reducing agent, ink, pigment, dispersant, setting regulator, expansion agent, shrinkage reducing agent, etc.

[0043] As the gypsum, anhydrous gypsum, hemihydrate gypsum, etc. may be used regardless of their types. These can be used alone or in combination of two or more.

[0044] Examples of the inorganic fine powder include calcium carbonate, blast furnace slag, silica fume, fly ash, etc. These can be used alone or in combination of two or more.

[0045] Examples of the thickener include cellulose-based, protein-based, latex-based, modified acrylic-based, water-soluble polymer-based thickeners, and xanthan gum, diutan gum, starch ether, guar gum, polyacrylamide, carrageenan gum, agar, viscosity mineral-based bentonite, etc. It is preferable to use a modified acrylic-based or cellulose-based thickener. The thickener can be used alone or in combination of two or more. The content of the thickener in the hydraulic composition is preferably 0.001 to 1 part by mass, more preferably 0.01 to 0.5 part by mass with respect to 100 parts by mass of cement.

[0046] Examples of the defoaming agent include acrylic polymers, vinyl ether polymers, butadiene polymers, olefin polymers, dimethyl silicone, modified silicone, particularly polyether-modified silicone, fluorine-modified silicone, alkyl-modified silicone, alkyl-aralkyl-modified silicone, higher aliphatic ester-modified silicone, higher fatty acid amide-modified silicone, phenyl-modified silicone, mineral oil, nonionic surfactants, anionic surfactants, cationic surfactants, acetylene diol, hydrophobic silica, wax, metal soaps such as aluminum stearate, polyoxyalkylene glycol, etc., and any combination thereof.

[0047] Examples of the water reducing agent include naphthalene sulfonate formaldehyde condensate-based water reducing agents, melamine sulfonate formaldehyde condensate-based water reducing agents, polycarboxylic acid-based water reducing agents, lignin sulfonate-based water reducing agents, polystyrene sulfonate-based water reducing agents, phenol formaldehyde condensate-based water reducing agents, and aniline sulfonate-based water reducing agents. The water reducing agent has surfactant-like properties and serves as an emulsifier that stably disperses a dispersion obtained by mixing water and a compound having a hydroxyl group. The water reducing agent can improve the fluidity of the hydraulic composition and enhance the workability and constructability. The content of the water reducing agent in the hydraulic composition is preferably 0.01 to 20 parts by mass, more preferably 0.1 to 5 parts by mass, per 100 parts by mass of cement.

[0048] The hydraulic composition of this embodiment may be a dry composition that does not contain water and aggregate, or may be a concrete composition or a mortar composition that contains water and aggregate, and is preferably a mortar composition.

[0049] <Manufacturing method of hydraulic composition> The manufacturing method of the hydraulic composition of the present embodiment is not particularly limited as long as the components (A) to (D) in the hydraulic composition have a predetermined blending ratio. For example, a step of heating a mixture of (B) polyhydric alcohol and (C) polyvalent isocyanate to obtain a partial polymer (step 1), and a step of mixing (A) cement and the partial polymer to obtain a hydraulic composition, wherein the total amount of (B) polyhydric alcohol and (C) polyvalent isocyanate in the hydraulic composition satisfies at least one of the following conditions (1) and (2). (1) It is 18 parts by mass or less with respect to 100 parts by mass of the component (A). (2) It is 4.15% by mass or less with respect to 100% by mass of the total amount of the hydraulic composition.

[0050] In step 1, a mixture of (B) polyhydric alcohol and (C) polyvalent isocyanate is heated to obtain a partial polymer. The conditions for obtaining the partial polymer are not particularly limited as long as the hydroxyl group of (B) polyhydric alcohol and the isocyanate group of (C) polyvalent isocyanate react. For example, it is preferably carried out at 80 to 150°C. Also, the heating time is preferably 1 to 5 hours. Step 1 may be carried out under an inert atmosphere such as nitrogen or argon.

[0051] In step 2, the partial polymer obtained in step 1 and the cement are mixed so as to satisfy the condition of (1) or (2). The mixing may be carried out by a Hobart mixer or the like. The above-mentioned additional polyhydric alcohol, additional polyvalent isocyanate or other additives, which are optional components, may be blended with the cement together with the partial polymer, or may be blended after mixing the partial polymer and the cement. Also, for the aggregate and water, they may be blended with the cement together with the partial polymer, or may be blended after mixing the partial polymer and the cement.

[0052] <Method for manufacturing hardened product> The method for manufacturing the hardened product (cement-based hardened body) is not particularly limited, but may include a step of molding a hydraulic composition to obtain a molded body (Step 3), and a step of curing the molded body (Step 4). If the hydraulic composition does not contain water before Step 3, water is added to the hydraulic composition before Step 3. The molding method is not particularly limited, and the hydraulic composition is poured into a mold (such as a metal mold or a plastic mold). Degassing may be performed by a vibrator as needed. With the hydraulic composition contained in the mold, for example, it is left for about 1 to 5 days to obtain a molded body. When using a core material such as a reinforcing bar or a steel frame, the core material may be arranged in the mold in advance and then the hydraulic composition may be poured in.

[0053] In Step 4, the molded body obtained in Step 3 is cured. It may be demolded before curing. The curing method is not particularly limited, and any curing method such as sealed curing or underwater curing may be used. Curing is performed until the hydraulic composition solidifies.

[0054] Since the hardened product of this embodiment has high strength and low water absorption, it can be used in various applications such as building materials, bearing seat materials for bridges or viaducts, floor slabs (road bridges, railway bridges, etc.), wave dissipating blocks, pools, and underwater caissons. In particular, it is useful as a material for those that are partially in contact with water or frequently in contact with water in the use states such as bearing seat materials for bridges or viaducts, floor slabs (road bridges, railway bridges, etc.), and wave dissipating blocks.

Examples

[0055] <Preparation of partial polymer> Using a balance, 314.89 g of Actocol ED28 ((Component B1), manufactured by Mitsui Chemicals SKC Polyurethane Co., Ltd.), 41.63 g of dipropylene glycol ((Component B2)), and 102.94 g of EXCENOL 5030 ((Component B3), manufactured by AGC Inc.) were weighed and added to the separable flask body while weighing. While supplying N2 gas, the polyhydric alcohols were mixed. 138.55 g of Coronate T-100 (a polyvalent isocyanate, manufactured by Tosoh Corporation) was weighed and put into the separable flask body. While stirring, it was heated at 100 °C for 3 hours to prepare a partial polymer. The progress of the reaction of the partial polymer was evaluated based on JIS K 7301, and the end point was defined as the time when the content rate of the isocyanate group became approximately equal to the content rate when reacting with the hydroxyl groups of all polyhydric alcohols.

[0056] <Preparation of hydraulic composition> Each component was blended in the blending amounts shown in Table 1. Specifically, first, cement, silica sand, and additives (thickening agents, water reducing agents, etc.) were weighed and put into a Hobart mixer, and mixed for 1 minute to obtain a mixture. Next, the partial polymer adjusted as described above was put into the mixture and mixed by a Hobart mixer. Then, water was put into the mixture and further mixed by a Hobart mixer. In order to prevent poor mixing, after the start of mixing (for example, about 3 minutes), the Hobart mixer was stopped, and the materials attached to the stirring blades and the kettle were dropped. Mixing was started again, and the Hobart mixer was stopped (kneading was performed for about 15 minutes in total) to obtain a hydraulic composition. The prepared hydraulic composition was put into a mold. It was demolded after 3 days to obtain a molded body. The molded body was submerged in water and cured for 28 days (cured in water) to obtain a test piece.

[0057] The meanings of the symbols in Table 1 are as follows. c / s: mass ratio of cement to aggregate (cement / aggregate) p / c: mass ratio of partial polymer to cement (partial polymer / cement) p: blending amount of partial polymer (g) D1: blending amount of defoaming agent (g) C: blending amount of cement (g) S: blending amount of fine aggregate (silica sand) (g) A: blending amount of water reducing agent (g) W: blending amount of water Note that the following were used as cement, water reducing agent, and defoaming agent. Cement: Early-strength Portland cement (Blaine specific surface area 4500 cm2 / g, manufactured by Ube Mitsubishi Cement Corporation) Water reducing agent: Mighty 21P (manufactured by Kao Chemical Co., Ltd.) Defoaming agent: BYK1794 (manufactured by BYK-Chemie Japan Co., Ltd.)

[0058] <Method for Measuring Compressive Strength> (Compressive Strength) For each specimen in the examples and comparative examples, a compressive strength test was conducted. The test method for compressive strength followed the method described in JIS A 1171-2016 "Test Methods for Polymer Cement Mortar". The test results are shown in Table 1.

[0059] <Method for Measuring Water Absorption Level> It was measured according to the method described in "Test Method for Coefficient of Moisture Permeation Rate in Concrete Subjected to Short-Term Wetting" described in JSCE-G 582-2018.

[0060]

Table 1

Claims

1. A hydraulic composition comprising: (A) cement, (B) an optional polyhydric alcohol, (C) a polyvalent isocyanate, and (D) a urethane compound containing residues of the polyhydric alcohol and residues of the polyvalent isocyanate, wherein when the hydraulic composition contains the component (B), the component (B) contains a polyhydric alcohol contained as a residue in the component (D), the component (C) contains a polyvalent isocyanate contained as a residue in the component (D), the component (B) contains (B1) an ethylene oxide adduct or a propylene oxide adduct of a dihydric alcohol, (B2) a short-chain dihydric alcohol having a molecular weight of 200 or less, and (B3) an alcohol having a trivalency or higher, and a total amount of the components (B) to (D) satisfies at least one of the following conditions (1) and (2): A hydraulic composition. (1) It is 0.01 part by mass or more and 18 parts by mass or less with respect to 100 parts by mass of the component (A). (2) It is 0.01% by mass or more and 4.15% by mass or less with respect to 100% by mass of the total amount of the hydraulic composition.

2. The hydraulic composition according to claim 1, wherein the component (B1) is an ethylene oxide adduct of polypropylene oxide.

3. The hydraulic composition according to claim 1 or 2, further comprising an aggregate.

4. The hydraulic composition according to any one of claims 1 to 3, further comprising water.

5. A cured product which is a cured product of the hydraulic composition according to any one of claims 1 to 4.

6. A step of heating a mixture of a polyhydric alcohol and a polyvalent isocyanate to obtain a partial polymer containing a urethane compound, and a step of mixing (A) cement and the partial polymer to obtain a hydraulic composition, wherein a total amount of the polyhydric alcohol, the polyvalent isocyanate, and the urethane compound in the hydraulic composition satisfies at least one of the following conditions (1) and (2): A step, comprising: A method for producing a hydraulic composition, wherein the polyhydric alcohol contains an ethylene oxide adduct or a propylene oxide adduct of a dihydric alcohol, a short-chain dihydric alcohol having a molecular weight of 200 or less, and an alcohol having a trivalency or higher. (1) It is 0.01 part by mass or more and 18 parts by mass or less with respect to 100 parts by mass of the component (A). (2) It is 0.01% by mass or more and 4.15% by mass or less with respect to 100% by mass of the total amount of the hydraulic composition.

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