Strength enhancer for hydraulic composition, additive for hydraulic composition, hydraulic composition, hydraulic composition setting body, and manufacturing method of hydraulic composition

Abstract

To provide a strength enhancer for a hydraulic composition, having high strength on setting a hydraulic composition at initial material age and high compatibility with a polycarboxylic acid ether-based compound.SOLUTION: A strength enhancer for a hydraulic composition includes the following A component, the following B component, and water. A component : sodium silicate having a molar ratio of silicic acid anhydride to sodium oxide (silicic acid anhydride / sodium oxide) of 0.9 or over and 4.0 or under. B component: at least one selected from 2-4 valent polyhydric alcohols having a carbon number of 2-9.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a strength enhancer for hydraulic compositions, an additive for hydraulic compositions, a hydraulic composition, a hardened product of the hydraulic composition, and a method for producing the hydraulic composition. More specifically, the present invention relates to a strength enhancer for hydraulic compositions, an additive for hydraulic compositions, a hydraulic composition, a hardened product of the hydraulic composition, and a method for producing the hydraulic composition, which have high compatibility with polycarboxylic acid ether compounds and can improve the compressive strength of the hardened product of the hydraulic composition at an early age. [Background technology]

[0002] Conventionally, hydraulic compositions, such as concrete, are composed of cement, water, fine aggregate, coarse aggregate, chemical admixtures for hydraulic compositions, etc. Among these, the chemical admixtures for hydraulic compositions include water-reducing agents (cement dispersants) such as polycarboxylate ether compounds, hardening accelerators, etc.

[0003] Here, concrete products are manufactured by kneading materials such as hydraulic binders containing cement, water, aggregates, and cement dispersants, pouring the mixture into a formwork, and hardening the mixture. In this case, improving the strength of the concrete product (hardened hydraulic composition) at an early age leads to the production of more concrete products using the same formwork. For this reason, there is a demand for shortening the time it takes for the concrete to reach a strength that allows it to be removed from the formwork after pouring (see, for example, Patent Documents 1 and 2).

[0004] Specifically, Patent Document 1 discloses a method for producing ready-mix concrete that has the effect of increasing the strength of the early material age, and Patent Document 2 discloses an additive for a hydraulic composition that can produce a hardened body with high early strength. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-057469 A [Patent Document 2] JP 2019-104667 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the manufacturing method of ready-mixed concrete described in Patent Document 1 is still insufficient in terms of enhancing the strength at an early age, and is also insufficient in terms of compatibility with cement dispersants (particularly polycarboxylic acid ether compounds). In addition, the additive for hydraulic compositions described in Patent Document 2 has room for further improvement in terms of enhancing the strength at an early age and compatibility with cement dispersants (particularly polycarboxylic acid ether compounds). Therefore, there has been a demand for the development of a strength enhancer (strength enhancer for hydraulic compositions) that has high strength at an early age, that is, develops high strength early, and has high compatibility with polycarboxylic acid ether compounds.

[0007] In view of the above circumstances, the present invention has an object to provide a strength enhancer for hydraulic compositions which has high strength at an early age when the hydraulic composition is hardened and further has high compatibility with polycarboxylic acid ether compounds, an additive for hydraulic compositions containing the same, a hydraulic composition containing any of them, a hardened product of the hydraulic composition, and a method for producing the hydraulic composition. [Means for solving the problem]

[0008] As a result of intensive research aimed at solving the above problems, the present inventors have found that the above problems can be solved by containing a specific component A, a specific component B, and water. According to the present invention, the following strength enhancer for hydraulic compositions, additives for hydraulic compositions, hydraulic compositions, hardened products of hydraulic compositions, and methods for producing hydraulic compositions are provided.

[0009] [1] A strength enhancer for hydraulic compositions, comprising the following component A, the following component B, and water: Component A: Sodium silicate in which the molar ratio of silicic anhydride to sodium oxide (silicic anhydride / sodium oxide) is 0.9 or more and 4.0 or less. Component B: At least one selected from dihydric to tetrahydric polyhydric alcohols having 2 to 9 carbon atoms.

[0010] [2] The strength enhancer for hydraulic compositions according to [1], wherein the molar ratio of silicic anhydride to sodium oxide in the component A (silicic anhydride / sodium oxide) is 1.8 or more and 4.0 or less.

[0011] [3] The strength enhancer for hydraulic compositions according to [1], wherein a mass ratio (B / A) of the B component to the A component is 0.10 or more and 10.00 or less.

[0012] [4] The strength enhancer for hydraulic compositions according to the above [1], wherein the strength enhancer for hydraulic compositions contains the A component in an amount of 1 to 50 mass %, the B component in an amount of 1 to 50 mass %, and water in an amount of 40 to 80 mass %.

[0013] [5] An additive for hydraulic compositions, comprising the strength enhancer for hydraulic compositions according to any one of [1] to [4] above, and a polycarboxylic acid ether compound.

[0014] [6] A hydraulic composition comprising the strength enhancer for hydraulic compositions according to any one of [1] to [4] above, or the strength enhancer for hydraulic compositions according to any one of [1] to [4] above, and an additive for hydraulic compositions comprising a polycarboxylic acid ether compound.

[0015] [7] A hardened hydraulic composition, which is a hardened product of the hydraulic composition described in [6].

[0016] [8] A method for producing a hydraulic composition, comprising a step of adding, at the time of kneading the hydraulic composition, the strength enhancer for hydraulic compositions according to any one of [1] to [4] above, or an additive for hydraulic compositions containing the strength enhancer for hydraulic compositions according to any one of [1] to [4] above and a polycarboxylic acid ether compound. Effect of the Invention

[0017] The strength enhancer for hydraulic compositions of the present invention is capable of increasing the strength of the hydraulic composition at an early age when the composition is hardened, and further has the effect of being highly compatible with polycarboxylic acid ether compounds.

[0018] The additive for hydraulic compositions of the present invention contains the strength enhancer for hydraulic compositions of the present invention, and thereby has the effect of increasing the strength of the hydraulic composition at an early age when the composition is hardened, and further exhibiting the effect of reducing the occurrence of precipitation due to the high compatibility between the polycarboxylic acid ether compound, which is a constituent, and the strength enhancer for hydraulic compositions.

[0019] The hydraulic composition of the present invention contains the strength enhancer for hydraulic compositions of the present invention, or an additive containing the strength enhancer and a polycarboxylic acid ether compound, and thereby exhibits the effect of high strength at an early age when hardened.

[0020] The hydraulic composition hardened product of the present invention is formed by hardening the hydraulic composition of the present invention, and has the effect of high strength at an early age.

[0021] According to the method for producing a hydraulic composition of the present invention, by adopting a predetermined process, it is possible to obtain an effect of saving labor in the process for producing a hydraulic composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, the embodiments of the present invention will be described. However, the present invention is not limited to the following embodiments. Therefore, it should be understood that appropriate modifications, improvements, etc. can be made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. In the following examples, etc., % means % by mass, and parts means parts by mass, unless otherwise specified.

[0023] (1) Strength enhancer for hydraulic compositions: The strength enhancer for hydraulic compositions of the present invention contains the following component A, the following component B, and water. Component A: Sodium silicate in which the molar ratio of silicic anhydride to sodium oxide (silicic anhydride / sodium oxide) is 0.9 or more and 4.0 or less. Component B: At least one selected from dihydric to tetrahydric polyhydric alcohols having 2 to 9 carbon atoms.

[0024] Such a strength enhancer for hydraulic compositions can increase the strength of the hydraulic composition at an early age when the hydraulic composition is hardened. Furthermore, the strength enhancer for hydraulic compositions has high compatibility with polycarboxylic acid ether compounds. As a result, as will be described later in "Method for producing hydraulic compositions", the labor required in the production process of the hydraulic composition can be reduced.

[0025] The value of the mass ratio (B / A) of the B component to the A component is not particularly limited, but is preferably 0.10 or more and 10.00 or less, more preferably 0.30 or more and 3.50 or less, and particularly preferably 0.40 or more and 2.50 or less. By setting it in such a range, the strength of the hydraulic composition at an early age when hardening can be further increased, and further, the compatibility between the polycarboxylic acid ether compound and the strength enhancer for hydraulic compositions, which are the components, is further increased, and the occurrence of precipitation in a mixture of them (additive for hydraulic compositions) is further reduced.

[0026] Furthermore, the strength enhancer for hydraulic compositions of the present invention preferably contains 20 to 60 mass% of components A and B in total when the strength enhancer for hydraulic compositions is taken as 100 mass%. By setting the content in such a range, the compatibility between the polycarboxylic acid ether compound, which is a constituent, and the strength enhancer for hydraulic compositions is further increased, and the occurrence of precipitation is further reduced.

[0027] (1-1)A component: Component A is sodium silicate with a molar ratio of silicic anhydride to sodium oxide (silicic anhydride / sodium oxide) of 0.9 to 4.0. By allowing components A and B to coexist, the strength of the hydraulic composition at an early age during hardening can be increased. Furthermore, even when the strength enhancer for hydraulic compositions coexists with a polycarboxylic acid ether compound, separation or insoluble substances (precipitation) are less likely to occur.

[0028] The molar ratio of silicic anhydride to sodium oxide in component A (silicic anhydride / sodium oxide) is preferably 1.8 to 4.0, more preferably 2.3 to 4.0, and particularly preferably 2.8 to 4.0. By setting it in such a range, the strength of the hydraulic composition at an early age can be further increased when the hydraulic composition is hardened, and further the compatibility between the polycarboxylic acid ether compound and the strength enhancer for hydraulic compositions is further increased, and the occurrence of precipitation is further reduced.

[0029] Here, "sodium silicate" is generally expressed by the molecular formula Na2O·nSiO2·mH2O. The coefficient n of the above molecular formula, i.e., the molecular ratio of SiO2 / Na2O, is called the molar ratio. Furthermore, the relationship between the weight ratio and the molar ratio of the SiO2 component and the Na2O component is expressed by the following formula. Molar ratio = weight ratio (SiO2% / Na2O%) × formula weight of Na2O / formula weight of SiO2 =Weight ratio (SiO2% / Na2O%)×1.032

[0030] Furthermore, those with the coefficient n of 1 or less are called crystalline sodium silicate. On the other hand, those with the coefficient n of more than 1 are non-crystalline, the molar ratio of which can be continuously changed, and are commercially available as aqueous solutions or powder products. And, what is generally called water glass is an aqueous solution.

[0031] (1-2)B component: Component B is at least one selected from dihydric to tetrahydric polyhydric alcohols having 2 to 9 carbon atoms. When component B is allowed to coexist with component A, it is possible to increase the strength of the hydraulic composition at an early age when the hydraulic composition is hardened, and separation or formation of insoluble substances (precipitation) is unlikely to occur even when the strength enhancer for hydraulic compositions is allowed to coexist with a polycarboxylic acid ether compound.

[0032] Examples of polyhydric alcohols include ethylene glycol, propylene glycol, tetramethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, glycerin, and pentaerythritol. One or more of these polyhydric alcohols are used in combination. In particular, at least one selected from ethylene glycol, diethylene glycol, butanediol, 1,3-propanediol, glycerin, diglycerin, and trimethylolpropane is preferred. By using these, the strength of the hydraulic composition at the initial age during hardening can be further increased, and even when the strength enhancer for hydraulic compositions is coexistent with a polycarboxylic acid ether compound, separation and insoluble substances (precipitation) are more unlikely to occur.

[0033] (1-3) Other ingredients (ingredients C): The strength enhancer for hydraulic compositions of the present invention may contain another component (component C) in addition to components A and B.

[0034] Other components (component C) include, for example, alkanolamine compounds. The alkanolamine compounds do not impair the effects of using components A and B, i.e., the effect of increasing the strength of the hydraulic composition at an early age and the effect of preventing separation from the polycarboxylic acid ether compound and the formation of insoluble substances (precipitation).

[0035] Examples of the alkanolamine compound include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine, methylethanolamine, methylisopropanolamine, methyldiethanolamine, methyldiisopropanolamine, diethanolisopropanolamine, diisopropanolethanolamine, tetrahydroxyethylethylenediamine, N,N-bis(2-hydroxyethyl)2-propanolamine, N,N-bis(2-hydroxypropyl)-N-(hydroxyethyl)amine, N,N-bis(2-hydroxyethyl)-N-(2-hydroxypropyl)amine, N,N,N',N'-tetrakis(2-hydroxypropyl)ethylenediamine, tris(2-hydroxybutyl)amine, etc. Among these, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, and triisopropanolamine are preferred.

[0036] The other component (component C) may be used alone or in combination of two or more kinds.

[0037] The content ratio of each component in the strength enhancer for hydraulic compositions, i.e., the content ratios of component A, component B, and water in the total amount (100 mass%) of the strength enhancer for hydraulic compositions, can be, for example, as follows: That is, the content ratio of component A can be 1 to 50 mass%, the content ratio of component B can be 1 to 50 mass%, and the content ratio of water can be 40 to 80 mass%.

[0038] The strength enhancer for hydraulic compositions of the present invention is used when preparing a hydraulic composition by adding mixing water to a binder (hydraulic binder).

[0039] (2) Additives for hydraulic compositions: The hydraulic composition additive of the present invention contains the hydraulic composition strength enhancer of the present invention and a polycarboxylic acid ether compound. By containing the hydraulic composition strength enhancer of the present invention, such a hydraulic composition additive can increase the strength of the hydraulic composition at an early age when the hydraulic composition is hardened, and further, the compatibility between the polycarboxylic acid ether compound and the hydraulic composition strength enhancer, which are the components, is high, and the occurrence of separation and insoluble substances (precipitation) is reduced. As a result, as will be described later in "Method of manufacturing hydraulic composition", the labor in the manufacturing process of the hydraulic composition can be reduced.

[0040] (2-1) Strength enhancer for hydraulic compositions: The content of the strength enhancer for hydraulic compositions is not particularly limited and can be appropriately set, but can be, for example, 5 to 60 mass % in 100 mass % of the additive for hydraulic compositions.

[0041] (2-2) Polycarboxylic acid ether compounds: The hydraulic composition additive of the present invention contains a polycarboxylic acid ether compound as a dispersant. The hydraulic composition strength enhancer of the present invention has high compatibility with the polycarboxylic acid ether compound. Therefore, the hydraulic composition additive of the present invention has reduced occurrence of separation and precipitation.

[0042] Examples of the polycarboxylic acid ether compound include those having a structural unit 1 derived from a compound represented by the following general formula (1) and a structural unit 2 derived from an unsaturated carboxylic acid or a salt thereof.

[0043] [ka] (In the general formula (1), R 1 A is an alkenyl group having 2 to 5 carbon atoms, or an unsaturated acyl group having 3 to 4 carbon atoms. 1 O is an oxyalkylene group having 2 to 4 carbon atoms. m is an integer of 2 to 300. R 2is a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or an aliphatic acyl group having 1 to 22 carbon atoms.

[0044] Furthermore, it may also have a structural unit 3 derived from an unsaturated carboxylic acid ester.

[0045] In the additive for hydraulic composition of the present invention, when the total content of the strength enhancer for hydraulic composition excluding water (i.e., a mixture of components A, B and C) and the polycarboxylic acid ether compound is taken as 100 mass%, the content of the polycarboxylic acid ether compound is preferably 10 to 90 mass%, more preferably 10 to 85 mass%, further preferably 10 to 80 mass%, and particularly preferably 10 to 75 mass%. By setting the content in such a range, the strength of the hydraulic composition at an early age can be increased when the hydraulic composition is hardened, and further, the compatibility between the polycarboxylic acid ether compound, which is a constituent, and the strength enhancer for hydraulic composition is high, and the occurrence of separation or insoluble substances (precipitation) is reduced.

[0046] The additive for hydraulic compositions of the present invention may further contain other components in addition to the strength enhancer for hydraulic compositions of the present invention and the polycarboxylic acid ether compound.

[0047] The other components are not particularly limited, and additives that are added to conventionally known additives for hydraulic compositions can be appropriately selected and used.

[0048] The content of the other components may be, for example, 0 to 20 mass % in 100 mass % of the additive for hydraulic composition.

[0049] (3) Hydraulic composition: The hydraulic composition of the present invention contains the hydraulic composition strength enhancer of the present invention, or the hydraulic composition additive containing the hydraulic composition strength enhancer and a polycarboxylic acid ether compound (i.e., the hydraulic composition additive of the present invention). By containing the hydraulic composition strength enhancer of the present invention, or the hydraulic composition additive containing the strength enhancer and a polycarboxylic acid ether compound, such a hydraulic composition has high strength at an early age when hardened.

[0050] The hydraulic composition of the present invention may contain a binder (hydraulic binder), water, fine aggregate, and coarse aggregate, similarly to conventionally known hydraulic compositions.

[0051] The hydraulic composition of the present invention is not particularly limited in terms of the content ratio of the hydraulic composition strength enhancer of the present invention or the hydraulic composition additive of the present invention, and can be appropriately set. For example, the content ratio of the hydraulic composition strength enhancer of the present invention can be 0.01 to 3 mass% relative to 100 mass% of the binder. Also, the content ratio of the hydraulic composition additive of the present invention can be 0.1 to 5 mass% relative to 100 mass% of the binder.

[0052] Examples of the binder include various types of Portland cement, such as ordinary Portland cement, moderate heat Portland cement, low heat Portland cement, high early strength Portland cement, and sulfate resistant Portland cement, as well as various types of cement, such as blast furnace cement, fly ash cement, and silica fume cement.

[0053] Furthermore, as the binder, various admixtures such as fly ash, ground granulated blast furnace slag, ground limestone, stone powder, silica fume, expansive agent, etc. may be used in combination with the various cements mentioned above.

[0054] Examples of fine aggregate include river sand, mountain sand, land sand, sea sand, silica sand, crushed sand, various slag fine aggregates, and the like, but may also include those containing fine particles such as clay.

[0055] Examples of coarse aggregate include river gravel, mountain gravel, land gravel, crushed stone, various types of slag coarse aggregate, lightweight aggregate, and the like.

[0056] The hydraulic composition of the present invention may further contain other components as appropriate within the range in which the effect is not impaired. Examples of such other components include a setting retarder consisting of a sugar, an oxycarboxylate, etc., a dispersing component consisting of sodium ligninsulfonate, etc., an air-entraining agent consisting of an anionic surfactant, etc., a defoamer consisting of an oxyalkylene compound, etc., a hardening accelerator consisting of an alkanolamine, etc., a shrinkage reducer consisting of a polyoxyalkylene alkyl ether, etc., a thickener consisting of a cellulose ether compound, etc., a preservative consisting of an isothiazolinone compound, etc., and a rust inhibitor consisting of a nitrite, etc.

[0057] The content of the other components may be, for example, 0 to 5% by mass relative to 100% by mass of the binder.

[0058] In the hydraulic composition of the present invention, the ratio of water to binder (water / binder ratio) can be appropriately selected from conventionally known ratios, and can be, for example, 25 to 70 mass %.

[0059] This hydraulic composition is filled into a formwork or the like and cured at room temperature or the like to obtain a hardened product such as hardened mortar or concrete.

[0060] (4) Manufacturing method of hydraulic composition: The method for producing a hydraulic composition of the present invention is a method comprising a step of adding the strength enhancer for hydraulic compositions of the present invention or an additive for hydraulic compositions containing the strength enhancer for hydraulic compositions of the present invention and a polycarboxylic acid ether compound when kneading the hydraulic composition.

[0061] According to this method, by using a hydraulic composition strength enhancer or a hydraulic composition additive containing a hydraulic composition strength enhancer, and adding the hydraulic composition during kneading, it is not necessary to add component A after kneading, and therefore it is possible to reduce the effort in the manufacturing process of the hydraulic composition.

[0062] Specifically, conventionally, the A component contained in the strength enhancer for hydraulic compositions and the cement dispersant have poor compatibility, and when they are mixed, separation or insoluble substances (precipitation) occur, so there has been a tendency to avoid combining them into one liquid. In other words, the timing of adding these is also different. Specifically, the dispersant is added during mixing, while the A component (especially water glass) is usually added after mixing. In this way, it was necessary to add the A component in addition to the dispersant. Here, by adopting the strength enhancer for hydraulic compositions of the present invention, the A component can be added at the same time as the dispersant is added during mixing, and the addition after mixing is unnecessary. In addition to the case where the strength enhancer for hydraulic compositions of the present invention and the dispersant are added separately, it is also possible to prepare a one-component mixture of a cement dispersant and a strength enhancer for hydraulic compositions containing component A in advance, as in the additive for hydraulic compositions of the present invention (i.e., an additive for hydraulic compositions containing the strength enhancer for hydraulic compositions of the present invention and a polycarboxylic acid ether compound), so that even in the case of preparing a one-component mixture in this way, there is no need to add the dispersant after mixing.

[0063] Furthermore, by using the hydraulic composition additive containing the hydraulic composition strength enhancer and the polycarboxylic acid ether compound of the present invention, equipment can be omitted in the manufacturing process, and the space for arranging the equipment is not required. Specifically, if the compatibility of the hydraulic composition strength enhancer and the polycarboxylic acid ether compound is insufficient, separation and the generation of insoluble substances are confirmed. Therefore, in order to avoid the occurrence of separation and insoluble substances, it is necessary to prepare a storage tank for chemical admixtures and a storage tank for strength enhancer for hydraulic composition, and store the hydraulic composition strength enhancer and the chemical admixture (containing the polycarboxylic acid ether compound) in each tank. In other words, it becomes difficult to operate the hydraulic composition strength enhancer in one storage tank for chemical admixtures that is conventionally used in concrete manufacturing plants, etc. On the other hand, if the compatibility of the hydraulic composition strength enhancer and the polycarboxylic acid ether compound is sufficient, the labor of preparing and managing each storage tank can be omitted. Furthermore, the operation and management of the storage tanks, etc. are reduced, and the labor of the manufacturing process can be omitted.

[0064] (5) Cured hydraulic composition: The hydraulic composition hardened product of the present invention is a hardened product of the hydraulic composition of the present invention. This hydraulic composition hardened product is formed by hardening the hydraulic composition of the present invention, and has high strength at an early age.

[0065] The hardened hydraulic composition specifically refers to hardened mortar (hardened mortar body), hardened concrete (hardened concrete body), and the like. EXAMPLES

[0066] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0067] First, Components A to C (alkanolamines) used in the strength enhancers for hydraulic compositions in the Examples and Comparative Examples are shown in Tables 1 to 3 below.

[0068] [Table 1]

[0069] [Table 2]

[0070] [Table 3]

[0071] Next, the P component (polycarboxylic acid ether compound) used in the hydraulic composition additives of the Examples and Comparative Examples is shown in Table 4 below.

[0072] Here, the production method of the P component (P-1 to P-4) will be described below.

[0073] (Production method of P-1) 241.7g of ion-exchanged water, 143.2g of α-methacryloyl-ω-methoxy-poly(n=9)oxyethylene, 33.5g of methacrylic acid, 8.7g of methyl acrylate, and 4.4g of 3-mercaptopropionic acid as a chain transfer agent were charged into a reaction vessel and dissolved uniformly under stirring. After that, the atmosphere in the reaction vessel was replaced with nitrogen, and the temperature of the reaction system was maintained at 65°C in a hot water bath.

[0074] Next, 18.8 g of 1% hydrogen peroxide solution was added to the reaction system to initiate the polymerization reaction. Two hours after the start of the polymerization reaction, 10.7 g of 1% hydrogen peroxide solution was further added to the reaction system, and the system was kept at 65° C. for two hours to terminate the polymerization reaction.

[0075] Thereafter, a 30% aqueous solution of sodium hydroxide was added to adjust the pH of the reaction system to 8, and the concentration was adjusted to 40% with ion-exchanged water to obtain a 40% aqueous solution of a polycarboxylate ether compound (P-1).

[0076] When this polycarboxylic acid ether compound (P-1) was analyzed by gel permeation chromatography (GPC), it was found that the mass average molecular weight was 17,000.

[0077] (P-2 manufacturing method) 193.5g of ion-exchanged water, 172.1g of α-methacryloyl-ω-methoxy-poly(n=45)oxyethylene, 19.1g of methacrylic acid, and 1.9g of 3-mercaptopropionic acid as a chain transfer agent were charged into a reaction vessel and uniformly dissolved with stirring. Then, 3.1g of 30% aqueous sodium hydroxide solution was slowly added with stirring. After the addition, the atmosphere in the reaction vessel was replaced with nitrogen, and the temperature of the reaction system was maintained at 65°C with a warm water bath.

[0078] Next, 36.6 g of 10% sodium persulfate aqueous solution was added to the reaction system to initiate the polymerization reaction. Two hours after the start of the polymerization reaction, 12.2 g of 10% sodium persulfate aqueous solution was further added to the reaction system, and the reaction system was maintained at 65° C. for two hours to terminate the polymerization reaction.

[0079] Thereafter, a 30% aqueous solution of sodium hydroxide was added to adjust the pH of the reaction system to 8, and the concentration was adjusted to 40% with ion-exchanged water to obtain a 40% aqueous solution of a polycarboxylic acid ether compound (P-2).

[0080] When this polycarboxylic acid ether compound (P-2) was analyzed by gel permeation chromatography (GPC), it was found that the mass average molecular weight was 20,000.

[0081] (Manufacturing method of P-3) 76.6 g of ion-exchanged water and 150.7 g of α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53)oxyethylene were charged into a reaction vessel and dissolved uniformly under stirring. After that, the atmosphere in the reaction vessel was replaced with nitrogen, and the temperature of the reaction system was maintained at 65° C. in a hot water bath.

[0082] Next, 8.8g of 1% hydrogen peroxide solution was dropped into the above reaction system over 3 hours, and an aqueous solution in which 9.6g of acrylic acid was uniformly dissolved in 39.1g of ion-exchanged water was dropped over 3 hours, and at the same time, an aqueous solution in which 0.8g of L-ascorbic acid and 0.6g of thioglycolic acid as a chain transfer agent were uniformly dissolved in 7.0g of ion-exchanged water was dropped over 4 hours. After that, the temperature was kept at 65°C for 2 hours to complete the polymerization reaction.

[0083] Thereafter, a 30% aqueous solution of sodium hydroxide was added to adjust the pH of the reaction system to 6, and the concentration was adjusted to 40% with ion-exchanged water to obtain a 40% aqueous solution of a polycarboxylic acid ether compound (P-3).

[0084] When this polycarboxylic acid ether compound (P-3) was analyzed by gel permeation chromatography (GPC), it was found that the mass average molecular weight was 28,000.

[0085] (Production method of P-4) 76.6 g of ion-exchanged water and 158.3 g of α-methallyl-ω-hydroxy-poly(n=68)oxyethylene were charged into a reaction vessel and dissolved uniformly under stirring. After that, the atmosphere in the reaction vessel was replaced with nitrogen, and the temperature of the reaction system was maintained at 65° C. in a hot water bath.

[0086] Next, 8.8g of 1% hydrogen peroxide solution was added dropwise over 3 hours, and an aqueous solution in which 7.0g of acrylic acid and 10.5g of hydroxyethyl acrylate were uniformly dissolved in 39.1g of ion-exchanged water was added dropwise over 3 hours, and at the same time, an aqueous solution in which 0.8g of L-ascorbic acid and 1.1g of 3-mercaptopropionic acid as a chain transfer agent were uniformly dissolved in 7.0g of ion-exchanged water was added dropwise over 4 hours. After that, the mixture was kept at 65°C for 2 hours to complete the polymerization reaction.

[0087] After the polymerization reaction was completed, the pH of the reaction system was adjusted to 7 by adding a 30% aqueous sodium hydroxide solution, and the concentration was adjusted to 40% with ion-exchanged water to obtain a 40% aqueous solution of a polycarboxylic acid ether compound (P-4).

[0088] When this polycarboxylic acid ether compound (P-4) was analyzed by gel permeation chromatography (GPC), it was found that the mass average molecular weight was 32,000.

[0089] [Table 4]

[0090] The P components (P-1 to P-4) contained the respective structural units 1 to 3 shown in Table 4 in the specified ratios and satisfied the specified physical properties. "P-5" is a reagent manufactured by Kishida Chemical. "P-6" is Polfine 510-AN (manufactured by Takemoto Oil & Fat). "P-7" is Accelerate 100 (manufactured by Nissan Chemical).

[0091] In Table 4, L-1 to L-4 and M-1 to M-4 are as follows. L-1: α-methacryloyl-ω-methoxypoly(n=9)oxyethylene L-2: α-methacryloyl-ω-methoxypoly(n=45)oxyethylene L-3: α-(3-methyl-3-butenyl)-ω-hydroxypoly(n=53)oxyethylene L-4: α-methallyl-ω-hydroxypoly(n=68)oxyethylene M-1: Methacrylic acid M-2: Acrylic acid M-3: Methyl acrylate M-4: Hydroxyethyl acrylate

[0092] (Measurement of mass average molecular weight) The mass average molecular weight of the P components (P-1 to P-4) was measured by gel permeation chromatography analysis under the following conditions. Equipment: Shodex GPC-101 (Showa Denko) Column: OHpak SB-G + SB-804 HQ + SB-802.5 HQ (Showa Denko) Detector: Differential refractometer (RI) Eluent: 50mM sodium nitrate aqueous solution Flow rate: 0.7mL / min Column temperature: 40℃ Sample concentration: 0.5% by mass in eluent solution Standard material: Polyethylene glycol / polyethylene oxide (Agilent Technologies, Inc.)

[0093] (pH Measurement) The pH of the P components (P-1 to P-4) was measured under the following conditions. Equipment: pH meter (HORIBA) Sample concentration: 100g of ion-exchanged water for 1g of sample Temperature: 20℃

[0094] (Examples 1 to 36, Comparative Examples 1 to 4) (1) Preparation of strength enhancer for hydraulic composition: Component A (sodium silicate), component B (polyhydric alcohol), component C, and ion-exchanged water were mixed in the types and amounts shown in Table 5 below to prepare strength enhancers for hydraulic compositions (S-1 to S-36, SR-1 to SR-4).

[0095] [Table 5]

[0096] In Table 5, "Component A + Component B (mass %)" indicates the total ratio (mass %) of "Component A and Component B" when the strength enhancer for hydraulic composition is taken as 100 mass %.

[0097] (Examples 37 to 82, Comparative Examples 5 to 11) (2) Preparation of additives for hydraulic compositions: The hydraulic composition strength enhancers (S component), P component (polycarboxylic acid ether compound), and ion-exchanged water of Examples 1 to 36 and Comparative Examples 1 to 4 were mixed to obtain the "P component / hydraulic composition strength enhancer (mass ratio)" and hydraulic composition additive concentrations shown in Table 6 below to prepare hydraulic composition additives (M-1 to M-46, MR-1 to MR-7).

[0098] [Table 6]

[0099] (Formulation stability) Each of the prepared hydraulic composition additives (M-1 to M-46, MR-1 to MR-7) was left to stand in an environment at 20°C after preparation, and the condition was checked 3 days, 1 week, 2 weeks, and 1 month after preparation of the hydraulic composition additive, and the "formulation stability" was evaluated according to the following evaluation criteria.

[0100] S: If no separation or insoluble matter is found even after one month has passed since the additive was made A: If no separation or insoluble matter was observed 2 weeks after the additive was prepared (miscible), but separation or insoluble matter was observed 1 month after the additive was prepared. B: No separation or insoluble matter was observed even after one week from the preparation of the additive (miscibility), but separation or insoluble matter was observed two weeks from the preparation of the additive. C: No separation or insoluble matter was observed 3 days after the additive was prepared (miscible), but separation or insoluble matter was observed 1 week after the additive was prepared. D: When separation or insoluble matter is confirmed 3 days after preparation of the additive.

[0101] (Examples 83 to 128, Comparative Examples 12 to 19) (3) Preparation of hydraulic composition: Next, hydraulic compositions of Examples 83 to 128 and Comparative Examples 12 to 19 were prepared as follows.

[0102] First, ordinary Portland cement (an equal mixture of Pacific Cement Corporation, Ube Mitsubishi Cement Corporation, and Sumitomo Osaka Cement Co., Ltd., density 3.16 g / cm3) was mixed in a 50-liter forced twin-shaft mixer under the mixing conditions shown in Table 7 below. 3 ), fine aggregate (Oi River watershed land sand, density 2.58g / cm 3), coarse aggregate (Okazaki crushed stone, density 2.66g / cm 3 ) were added in order and mixed dry for 10 seconds.

[0103] Next, the additive for hydraulic composition prepared as shown in Table 6 and an antifoaming agent (AFK-2 (trade name) manufactured by Takemoto Yushi Co., Ltd.) were added to the mixing water, and the additive for hydraulic composition and the antifoaming agent were considered as part of the mixing water and added together with the mixing water (i.e., the additive for hydraulic composition was added during mixing), and the mixture was mixed for 90 seconds. In this way, a hydraulic composition was prepared. The results are shown in Table 8.

[0104] In Table 8, in Comparative Examples 15 to 18, P components (P-1 to P-4) were used as the additive for the hydraulic composition (see Table 4).

[0105] The hydraulic composition additive was added in an amount that would give the fresh concrete the desired fluidity (specifically, a slump of 21±1.5 cm). The antifoaming agent was added in an amount of 0.005% relative to the cement, so that the air content of the mixed concrete (fresh concrete) would be 2% or less.

[0106] [Table 7]

[0107] [Table 8]

[0108] The slump and air content in the prepared hydraulic compositions were measured as follows.

[0109] (slump) The hydraulic composition (fresh concrete) immediately after mixing was measured in accordance with JIS A1101. In this manner, it was confirmed that the desired fluidity (slump value: 21±1.5 cm) was achieved.

[0110] (Air volume) The hydraulic composition (fresh concrete) immediately after mixing was measured in accordance with JIS A1128. In this manner, it was confirmed that the desired air content (2% or less) was achieved.

[0111] (Compressive strength of hardened concrete) Furthermore, a hardened body (hardened concrete body) was produced using the prepared hydraulic composition, and the compressive strength of this hardened body was measured by the following method. The results are shown in Table 8.

[0112] First, nine cylindrical tinplate concrete specimen molding forms (product name "Summit Mold", Sumitomo Cement, formwork bottom diameter: 100 mm, formwork height: 200 mm) were prepared based on JIS A1132. Each of the nine forms was then filled with concrete using the two-layer filling method. After that, polyethylene wrap was placed over the formwork openings to prevent moisture from evaporating, and the forms were left to cure for one hour in a room at 20°C (pre-curing).

[0113] After the preliminary curing, the specimen was moved together with the specimen molding form into a chamber set at 45℃ and 80%RH humidity for one hour of heat curing, and then moved again together with the specimen molding form into a chamber set at 60℃ and 98%RH humidity for a further two hours of heat curing.

[0114] After the heat curing was completed, the concrete was cooled to 20°C at a rate of 20°C / hour to prepare a hardened concrete body. Then, the concrete was cured in a chamber (20°C, humidity 60% RH) until it reached the specified age.

[0115] Sixteen hours after the preparation of the hardened concrete, three hardened specimens together with the specimen molding formwork were removed from the chamber, the specimens (hardened concrete) were demolded from the formwork, and the compressive strength at 16 hours of age was measured, and the average value of the three specimens was calculated.

[0116] Similarly, 24 hours after preparation of the hardened concrete, three hardened specimens together with the specimen molding formwork were removed from the chamber, the specimens (hardened concrete) were demolded from the formwork, and the compressive strength at 24 hours of age was measured, and the average value of the three specimens was calculated.

[0117] Furthermore, the remaining three specimens were removed from the chamber at the age of 24 hours, demolded from the specimen molding formwork, and cured in air at 20°C and 60% RH until the age of 28 days. The compressive strength of the specimens (hardened concrete) at the age of 28 days was then measured, and the average value of the three specimens was calculated.

[0118] (Calculation of compressive strength ratio) This is a ratio to the compressive strength of an example in which only the same hydraulic composition dispersant was used (example in which no hydraulic composition strength enhancer was added) (i.e., the compressive strength of Comparative Examples 15 to 18), and the ratio (compressive strength ratio) was calculated assuming that the compressive strength of an example in which no hydraulic composition strength enhancer was added (compressive strength of Comparative Examples 15 to 18) was 100%. The performance of the hydraulic composition strength enhancer (initial age strength enhancing effect at the time of hardening of the hydraulic composition) was evaluated based on this compressive strength ratio.

[0119] (Evaluation criteria for compressive strength ratio (strength enhancement effect)) The evaluation criteria for compressive strength ratio at 16 hours and 24 hours (1 day) are shown below. S: Compressive strength ratio is 140% or more A: Compressive strength ratio is 130% or more and less than 140% B: Compressive strength ratio is 120% or more and less than 130% C: Compressive strength ratio is 110% or more and less than 120% D: Compressive strength ratio is less than 110%

[0120] The evaluation criteria for compressive strength ratio at 28 days are shown below. S: Compressive strength ratio is 113% or more A: Compressive strength ratio is 109% or more and less than 113% B: Compressive strength ratio is 106% or more and less than 109% C: Compressive strength ratio is 103% or more and less than 106% D: Compressive strength ratio is less than 103%

[0121] (result) As shown in Tables 6 and 8, the strength of the hydraulic composition at the initial age during hardening could be increased by adding the hydraulic composition strength enhancer and hydraulic composition additive of this example to the hydraulic composition. Furthermore, it was confirmed that the hydraulic composition strength enhancer of this example has high compatibility with the cement dispersant (polycarboxylic acid ether compound). [Industrial Applicability]

[0122] The hydraulic composition strength enhancer and hydraulic composition additive of the present invention can be added to hydraulic compositions such as concrete and mortar. The hydraulic composition of the present invention can be used to form a hydraulic composition hardened body such as a concrete hardened body and a mortar hardened body. The hydraulic composition hardened body of the present invention can be used as various concrete products. The method for producing the hydraulic composition of the present invention can be adopted as the method for producing the hydraulic composition of the present invention described above.

Claims

1. A strength enhancer for hydraulic compositions, comprising the following component A, the following component B, and water: Component A: sodium silicate having a molar ratio of silicic anhydride to sodium oxide (silicic anhydride / sodium oxide) of 0.9 or more and 4.0 or less. Component B: at least one selected from dihydric, trihydric, or tetrahydric polyhydric alcohols having 2 to 9 carbon atoms.

2. 2. The strength enhancer for hydraulic compositions according to claim 1, wherein the molar ratio of silicic anhydride to sodium oxide in the component A (silicic anhydride / sodium oxide) is 1.8 or more and 4.0 or less.

3. 2. The strength enhancer for hydraulic compositions according to claim 1, wherein a mass ratio (B / A) of the B component to the A component is 0.10 or more and 10.00 or less.

4. The strength enhancer for hydraulic compositions according to claim 1, wherein the strength enhancer for hydraulic compositions contains the A component in an amount of 1 to 50% by mass, the B component in an amount of 1 to 50% by mass, and water in an amount of 40 to 80% by mass.

5. 5. An additive for hydraulic compositions, comprising the strength enhancer for hydraulic compositions according to claim 1 and a polycarboxylic acid ether compound.

6. A hydraulic composition comprising the strength enhancer for hydraulic compositions according to any one of claims 1 to 4, or the strength enhancer for hydraulic compositions according to any one of claims 1 to 4 and an additive for hydraulic compositions comprising a polycarboxylic acid ether compound.

7. A hardened hydraulic composition, which is a hardened product of the hydraulic composition according to claim 6.

8. A method for producing a hydraulic composition, comprising the step of adding the strength enhancer for hydraulic compositions according to any one of claims 1 to 4, or an additive for hydraulic compositions containing the strength enhancer for hydraulic compositions according to any one of claims 1 to 4 and a polycarboxylic acid ether compound, during kneading of the hydraulic composition.

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