Dispersant for hydraulic composition and hydraulic composition

Abstract

Provided is a dispersant for hydraulic compositions that has dispersing properties and can reduce the viscosity of hydraulic compositions. [Solution] A dispersant for hydraulic compositions, comprising a polymer (P) having a structural unit (1) formed from a compound represented by general formula (1), a structural unit (2) formed from a compound represented by general formula (2), and a structural unit (3) formed from at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, and salts thereof, wherein the mass average molecular weight of this polymer (P) is 5,000 to 5,000,000.

Description

[Technical Field]

[0001] The present invention relates to a dispersant for hydraulic compositions and a hydraulic composition. More specifically, the present invention relates to a dispersant for hydraulic compositions and a hydraulic composition that can reduce the viscosity of the hydraulic composition while having good dispersing performance. [Background technology]

[0002] Conventionally, dispersants for hydraulic compositions have the function of imparting fluidity to hydraulic compositions such as concrete (see, for example, Patent Document 1).

[0003] Known examples of dispersants for hydraulic compositions include naphthalene compounds and polycarboxylic acid compounds.

[0004] Furthermore, in recent years, with the depletion of high-quality aggregates such as river sand, the proportion of aggregates (inferior quality aggregates) that have not been actively used in the past is increasing. It is known that hydraulic compositions using such aggregates (aggregates of inferior quality compared to river sand, etc.) become highly viscous, even at normal water-binder ratios (W / B), resulting in poor workability.

[0005] In view of this situation, as in Patent Documents 2 and 3, there have been reported substances (water-reducing agents, admixtures) that reduce the viscosity of hydraulic compositions. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-125366 [Patent Document 2] Chinese Patent Application Publication No. 115010875 [Patent Document 3] Chinese Patent Application Publication No. 115960320 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the water-reducing agent described in Patent Document 2 and the admixture described in Patent Document 3 are still insufficient in their effect of reducing the viscosity of hydraulic compositions, and there is room for further improvement.

[0008] In other words, there has been a demand for the development of a dispersant (dispersant for hydraulic compositions) that can further reduce the viscosity of hydraulic compositions (even if aggregate of inferior quality compared to river sand, etc. is used, the viscosity can be further reduced).

[0009] In view of the above circumstances, an object of the present invention is to provide a dispersant for hydraulic compositions that has good dispersing performance and can reduce the viscosity of hydraulic compositions. [Means for solving the problem]

[0010] 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 using a specific polymer. According to the present invention, the following dispersant for hydraulic compositions and hydraulic compositions are provided.

[0011] [1] A polymer (P) comprising a structural unit (1) formed from a compound represented by the following general formula (1), a structural unit (2) formed from a compound represented by the following general formula (2), and a structural unit (3) formed from at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, and salts thereof, The weight average molecular weight of the polymer (P) is 8000~500000 Yes the law of nature, The polymer (P) contains 10 to 49 mass% of the structural unit (1), 30 to 89 mass% of the structural unit (2), and 1 to 25 mass% of the structural unit (3) converted into a sodium salt, where the total mass of the structural unit (1), the structural unit (2), and the structural unit (3) converted into a sodium salt is taken as 100 mass%. A dispersant for hydraulic compositions, characterized by:

[0012] [ka] (In general formula (1), X 1 is an alkenyl group having 6 to 18 carbon atoms, and A 1O is an alkyleneoxy group having 2 to 4 carbon atoms, and m is 5~150 is the number of Y 1 is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms.

[0013] [ka] (In general formula (2), X 2 is an alkenyl group having 2 to 5 carbon atoms or an unsaturated acyl group having 3 to 4 carbon atoms, and A 2 O is an alkyleneoxy group having 2 to 4 carbon atoms, and n is 5~150 is the number of Y 2 is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms.

[0014] delete

[0015] [ 2 The dispersant for hydraulic compositions according to [1] above, wherein the polymer (P) has a mass proportion of the structural unit (2) greater than the mass proportion of the structural unit (1).

[0016] [ 3 ] In the general formula (2), X 2 is an alkenyl group having 2 to 5 carbon atoms.

[0017] [ 4 Further, the composition contains an ether compound (A) which is a compound obtained by adding 1 to 500 moles of an alkylene oxide having 2 to 4 carbon atoms to 1 mole of a monohydric to tetrahydric aliphatic alcohol having 2 to 24 carbon atoms, The dispersant for hydraulic compositions according to [1] above, wherein the mass ratio (A / P) of the ether compound (A) to the polymer (P) is 0.01 to 0.25.

[0018] [ 5 ] Hydraulic binder, water, and the above [1]~[ 4 10. A hydraulic composition comprising the dispersant for hydraulic compositions according to any one of claims 1 to 9. [Effects of the Invention]

[0019] The dispersant for hydraulic compositions of the present invention has the effect of reducing the viscosity of hydraulic compositions while having good dispersing performance.

[0020] The hydraulic composition of the present invention exhibits the effect of reducing viscosity by containing the dispersant for hydraulic compositions of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, 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 changes, modifications, 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, % means % by mass, and parts means parts by mass, unless otherwise specified.

[0022] (1) Dispersant for hydraulic compositions: The dispersant for hydraulic compositions of the present invention contains a polymer (P) having a structural unit (1) formed from a compound represented by the following general formula (1), a structural unit (2) formed from a compound represented by the following general formula (2), and a structural unit (3) formed from at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, and salts thereof: do. Mass average molecular weight of polymer (P) teeth , 5000-5,000,000 In the present invention, the is.

[0023] [ka] (In general formula (1), X 1 is an alkenyl group having 6 to 18 carbon atoms, and A 1 O is an alkyleneoxy group having 2 to 4 carbon atoms, and m is 5~150 is the number of Y 1is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms.

[0024] [ka] (In general formula (2), X 2 is an alkenyl group having 2 to 5 carbon atoms or an unsaturated acyl group having 3 to 4 carbon atoms, and A 2 O is an alkyleneoxy group having 2 to 4 carbon atoms, and n is 5~150 is the number of Y 2 is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms.

[0025] This dispersant for hydraulic compositions can reduce the viscosity of hydraulic compositions while having good dispersing properties.

[0026] (1-1) Polymer (P): The polymer (P) has structural units (1) to (3) and a predetermined weight average molecular weight. The structural units (1) to (3) and weight average molecular weight of the polymer (P) are described below.

[0027] (1-1a) Building block (1): The structural unit (1) is a structural unit formed from a compound represented by general formula (1), and specifically, X 1 is an alkenyl group having 6 to 18 carbon atoms. 1 The alkenyl group has a large number of carbon atoms.

[0028] As described above, X in general formula (1) 1 is an alkenyl group having 6 to 18 carbon atoms, preferably an alkenyl group having 8 to 18 carbon atoms, and more preferably an alkenyl group having 8 to 9 carbon atoms.

[0029] In this specification, the term "alkenyl group" refers to a linear, branched, or cyclic monovalent aliphatic unsaturated hydrocarbon group having at least one non-aromatic carbon-carbon double bond. Among these, linear groups are preferred.

[0030] Specific examples of the alkenyl group having 6 to 18 carbon atoms include a hexenyl group, a heptenyl group, an octenyl group, a nonenyl group, a decenyl group, an undecenyl group, a dodecenyl group, a tridecenyl group, a tetradecenyl group, a pentadecenyl group, a hexadecenyl group, a heptadecenyl group, and an octadecenyl group.

[0031] A in general formula (1) 1 O is an alkyleneoxy group having 2 to 4 carbon atoms (however, when a plurality of such alkyleneoxy groups are present, one type may be used alone or two or more types may be used). Of these, an alkyleneoxy group having 2 carbon atoms is preferred.

[0032] In general formula (1), m is the average number of moles of AO added, and is a number from 1 to 500, preferably a number from 2 to 300, and more preferably a number from 5 to 150. In the present invention, m is a number of 5 to 150.

[0033] Y in general formula (1) 1 is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms, and among these, a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms is preferred, and a hydrogen atom or a hydrocarbon group having 1 carbon atom is more preferred.

[0034] (1-1b) Building block (2): The structural unit (2) is a structural unit formed from a compound represented by general formula (2). By containing this structural unit (2) in addition to the structural unit (1), the polymer (P) can exhibit good dispersing performance in a dispersant for hydraulic compositions and can also reduce the viscosity of the hydraulic composition.

[0035] X in general formula (2) 2is an alkenyl group having 2 to 5 carbon atoms or an unsaturated acyl group having 3 to 4 carbon atoms, and is preferably an alkenyl group having 2 to 5 carbon atoms.

[0036] Specific examples of the alkenyl group having 2 to 5 carbon atoms include a vinyl group, an allyl group, a butenyl group, a methallyl group, a pentenyl group, a 3-methyl-2-butenyl group, and a 3-methyl-3-butenyl group.

[0037] Specific examples of the unsaturated acyl group having 3 to 4 carbon atoms include an acryloyl group, a methacryloyl group, and a crotonoyl group.

[0038] A in general formula (2) 2 O is an alkyleneoxy group having 2 to 4 carbon atoms (however, when a plurality of such alkyleneoxy groups are present, one type may be used alone or two or more types may be used). Of these, an alkyleneoxy group having 2 carbon atoms is preferred.

[0039] In the general formula (2), n is the average number of moles of AO added, and is a number from 1 to 500, preferably a number from 2 to 300, and more preferably a number from 5 to 150. In the present invention, n is a number from 5 to 150.

[0040] Y in general formula (2) 2 is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms, and among these, a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms is preferred, and a hydrogen atom or a hydrocarbon group having 1 carbon atom is more preferred.

[0041] (1-1c) Building block (3): The structural unit (3) is a structural unit formed from at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, and salts thereof. By containing such a structural unit (3) in addition to the structural units (1) and (2), the polymer (P) can exhibit good dispersing performance in the dispersant for hydraulic compositions and can also reduce the viscosity of the hydraulic composition.

[0042] The structural unit (3) preferably contains at least acrylic acid or a salt thereof, which provides high dispersibility and further reduces the viscosity of the hydraulic composition.

[0043] (Mass Proportion of Structural Units (1) to (3)) When the total mass proportions of the structural units (1), (2), and (3) converted into sodium salts is taken as 100 mass%, the polymer (P) preferably comprises 1 to 98 mass% of the structural unit (1), 1 to 98 mass% of the structural unit (2), and 1 to 50 mass% of the structural unit (3) converted into sodium salts. These mass proportions are more preferably 1 to 90 mass% of the structural unit (1), 1 to 90 mass% of the structural unit (2), and 1 to 40 mass% of the structural unit (3) converted into sodium salts, and particularly preferably 10 to 45 mass% of the structural unit (1), 30 to 89 mass% of the structural unit (2), and 1 to 25 mass% of the structural unit (3) converted into sodium salts. By using the above mass proportions, the polymer (P) can exhibit good dispersing performance in a dispersant for hydraulic compositions while also reducing the viscosity of the hydraulic composition. In the present invention, when the total mass proportions of the structural unit (1), the structural unit (2), and the structural unit (3) converted into a sodium salt is taken as 100 mass%, the polymer (P) contains 10 to 49 mass% of the structural unit (1), 30 to 89 mass% of the structural unit (2), and 1 to 25 mass% of the structural unit (3) converted into a sodium salt.

[0044] The polymer (P) preferably has a larger mass proportion of the structural unit (2) than the mass proportion of the structural unit (1).By doing so, the polymer (P) can exhibit good dispersing performance in the dispersant for hydraulic compositions, and can also reduce the viscosity of the hydraulic composition.

[0045] The sodium salt conversion of "structural unit (3) converted into its sodium salt" can be performed as follows. That is, the conversion is performed assuming that the unsaturated carboxylic acid and salts thereof of the structural unit (3) are all sodium salts of unsaturated carboxylic acid. For example, structural units formed from acrylic acid are all converted as structural units formed from sodium acrylate, and structural units formed from maleic acid and maleic anhydride are all converted as structural units formed from disodium maleate.

[0046] (1-1d) Other structural units: The polymer (P) may further contain other structural units in addition to the structural units (1) to (3) above. Examples of such other structural units include those formed from compounds such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, (meth)acrylic acid alkyl esters, (meth)allylsulfonic acid (salts), (meth)acrylamide, styrene, vinyl acetate, allylsulfonates, and methallylsulfonates.

[0047] The polymer (P) has a mass average molecular weight of 5,000 to 5,000,000, preferably 5,000 to 1,000,000, and more preferably 8,000 to 500,000. By adjusting the mass average molecular weight to such a range, the dispersant for hydraulic compositions can exhibit good dispersing performance while reducing the viscosity of the hydraulic composition.

[0048] The weight average molecular weight of the polymer (P) can be measured by gel permeation chromatography.

[0049] The content of the polymer (P) in the dispersant for hydraulic compositions is not particularly limited, but can be, for example, 10 to 100 mass %.

[0050] (1-1e) Synthesis method of polymer (P): The polymer (P) can be synthesized by a conventionally known method, such as radical polymerization using water as a solvent, radical polymerization using an organic solvent as a solvent, and solvent-free radical polymerization.

[0051] The radical polymerization initiator used in the radical polymerization is not particularly limited as long as it decomposes at the polymerization reaction temperature and generates radicals, such as peroxides such as benzoyl peroxide, hydrogen peroxide, ammonium persulfate, sodium persulfate, and potassium persulfate, and azo compounds such as 2,2′-azobisisobutyronitrile and 2,2′-azobis(2-methylbutyronitrile).

[0052] Furthermore, reducing agents such as sodium hydrogen sulfite, sodium bisulfite, Fe(II) salts such as Mohr's salt, sodium hydroxymethanesulfinate dihydrate, and ascorbic acid, and amine compounds such as ethylenediamine and glycine can also be used in combination as accelerators.

[0053] A chain transfer agent may be used to adjust the mass average molecular weight of the resulting polymer (P) to fall within a desired range.

[0054] In the polymerization reaction, polymerization conditions such as polymerization temperature are appropriately determined depending on the polymerization method, solvent, polymerization initiator, and chain transfer agent used, but the lower limit of the polymerization temperature is preferably 0°C or higher, and the upper limit is preferably 150°C or lower. The lower limit is more preferably 30°C or higher, and even more preferably 50°C or higher. The upper limit is more preferably 120°C or lower, and even more preferably 100°C or lower.

[0055] (1-2) Ether compound (A): The dispersant for hydraulic compositions of the present invention further contains an ether compound (A) which is a compound obtained by adding 1 to 500 moles of alkylene oxide having 2 to 4 carbon atoms to 1 mole of mono- to tetrahydric aliphatic alcohol having 2 to 24 carbon atoms, and in this case, the mass ratio (A / P) of the ether compound (A) to the polymer (P) is preferably 0.01 to 0.25. By satisfying these conditions, the dispersing performance is high and the viscosity of the hydraulic composition can be reduced.

[0056] Furthermore, the ether compound (A) preferably contains a compound in which 1 to 500 moles of alkylene oxide having 2 to 4 carbon atoms are added to 1 mole of monohydric aliphatic alcohol having 2 to 18 carbon atoms and having an unsaturated bond. In this case, the mass ratio of ethylene oxide (alkylene oxide having 2 carbon atoms) in the alkylene oxide is preferably 60 mass% or more, more preferably 80 mass% or more. By satisfying these conditions, the dispersibility is high and the viscosity of the hydraulic composition can be further reduced.

[0057] The mass ratio (A / P) of the ether compound (A) to the polymer (P) is preferably 0.01 to 0.20, more preferably 0.01 to 0.18. By setting the mass ratio within this range, the dispersibility is high and the viscosity of the hydraulic composition can be further reduced.

[0058] The ether compound (A) may be the unreacted product obtained during the synthesis reaction of the polymer (P), or may be added separately so that the "A / P" ratio falls within the above-mentioned range.

[0059] Here, when the unreacted material (unreacted ether compound) in the synthesis reaction of polymer (P) is used as ether compound (A) (specifically, a part of ether compound (A)) as in the former case, in order to satisfy the above A / P, synthesis is carried out so that the amount of the unreacted material (unreacted ether compound) in the synthesis reaction of polymer (P) does not exceed the upper limit of the above A / P. To achieve this, a compound that forms structural unit (1), a compound that forms structural unit (2), and a compound that forms structural unit (3), all of which have sufficient purity, are polymerized by an appropriate method to obtain polymer (P).

[0060] (1-3) Other dispersant components: The dispersant for hydraulic compositions of the present invention may contain other dispersant components in addition to the polymer (P) and the ether compound (A).

[0061] Other dispersant components include, for example, setting retarding components such as sugars and oxycarboxylates, components with dispersing properties such as sodium lignin sulfonate, air-entraining agents such as anionic surfactants, antifoaming agents such as oxyalkylene compounds, hardening accelerators such as alkanolamines, shrinkage reducers such as polyoxyalkylene alkyl ethers, thickeners such as cellulose ether compounds, preservatives such as isothiazolinone compounds, and rust inhibitors such as nitrites.

[0062] The other dispersant components may be used alone or in combination of two or more.

[0063] (1-4) Method for producing dispersant for hydraulic composition: The dispersant for hydraulic compositions of the present invention is not particularly limited by its production method, and any known method can be used as appropriate. Specifically, the reaction solution obtained by synthesizing the polymer (P) can be used as a dispersant for hydraulic compositions as it is.

[0064] Since the ether compound (A) (i.e., the compound that forms the structural unit (1)) is used as a raw material for the polymer (P), unreacted ether compound (A) may remain in the reaction solution after the synthesis reaction of the polymer (P). Even in this case, the reaction solution containing the unreacted ether compound (A) can be used as it is as a dispersant for hydraulic compositions.

[0065] Furthermore, when the mass ratio (A / P) of the ether compound (A) to the polymer (P) is set to 0.01 to 0.25, the ether compound (A) can be further added as necessary to satisfy the desired A / P (mass ratio of the ether compound (A) to the polymer (P)), thereby obtaining a dispersant for hydraulic compositions.

[0066] The ether compound (A) added at this time may be the same as or different from the ether compound (A) used as a raw material for the polymer (P). Thereafter, other dispersant components can be added as necessary.

[0067] (2) Hydraulic composition: The hydraulic composition of the present invention contains a hydraulic binder, water, and the dispersant for hydraulic compositions of the present invention.

[0068] Such a hydraulic composition has reduced viscosity due to the inclusion of the dispersant for hydraulic compositions of the present invention.

[0069] (2-1) Hydraulic binder: Examples of hydraulic binders 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.Further examples include various types of gypsum such as anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum, and combinations of powders having latent hydraulic properties with alkaline stimulants, such as a combination of ground granulated blast furnace slag and calcium hydroxide.

[0070] Furthermore, various admixtures such as fly ash, ground granulated blast furnace slag, ground limestone, stone powder, silica fume, and expansive materials may be appropriately selected and used in combination as the hydraulic binder.

[0071] (2-2) Dispersant for hydraulic compositions: In the hydraulic composition of the present invention, the content ratio of the dispersant for hydraulic compositions of the present invention is not particularly limited and can be set appropriately. For example, the content ratio of the dispersant for hydraulic compositions of the present invention can be 0.001 to 3.0 parts by mass in terms of solid content per 100 parts by mass of the hydraulic binder.

[0072] (2-3) Aggregate: The hydraulic composition of the present invention may contain fine aggregate, coarse aggregate, etc., similarly to conventionally known hydraulic compositions.

[0073] Examples of fine aggregate include river sand, mountain sand, land sand, sea sand, silica sand, crushed sand, and various fine slag aggregates, but those containing fine particles such as clay may also be used.

[0074] Examples of coarse aggregate include river gravel, mountain gravel, land gravel, crushed stone, various types of slag coarse aggregate, lightweight aggregate, and the like.

[0075] (2-4) Other composition components: The hydraulic composition of the present invention may further contain other composition components as appropriate within the range that does not impair the effects. Examples of such other composition components include setting retarders such as sugars and oxycarboxylates, various water-reducing agents, air-entraining agents such as anionic surfactants, antifoaming agents such as oxyalkylene compounds, hardening accelerators such as alkanolamines, shrinkage-reducing agents such as polyoxyalkylene alkyl ethers, thickeners such as cellulose ether compounds, preservatives such as isothiazolinone compounds, and rust inhibitors such as nitrites.

[0076] The content of other composition components can be, for example, 0 to 5 parts by mass in terms of solid content per 100 parts by mass of the hydraulic binder.

[0077] In the hydraulic composition of the present invention, the ratio of water to hydraulic binder (water / binder ratio) can be suitably selected from conventionally known ratios, and can be, for example, 20 to 70 mass %.

[0078] (3) Cured product of hydraulic composition: The hydraulic composition of the present invention can be cured to form a cured product, specifically, a hardened mortar (hardened mortar product), a hardened concrete (hardened concrete product), or the like.

[0079] The hardened product of the hydraulic composition can be produced by a conventionally known method, specifically, a method in which the hydraulic composition is filled into a formwork or the like and cured at room temperature or by heat curing with steam, or the like. [Example]

[0080] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

[0081] (Examples 1 to 11, Comparative Examples 1 and 2) (1) Dispersant for hydraulic compositions: First, the compounds (P1-1 to P1-8, P2-1 to P2-6, P3-1 to P3-3) that form the structural units (1) to (3) that constitute the polymer (P) used in the dispersants for hydraulic compositions in Examples 1 to 11 and Comparative Examples 1 and 2 are shown in Tables 1 to 3 below. In Tables 1 to 3, the compounds that form each of the structural units (1) to (3) are referred to as "compounds that form structural unit (1)," etc. The compound that forms structural unit (1) is the compound represented by general formula (1), and the compound that forms structural unit (2) is the compound represented by general formula (2).

[0082] [Table 1]

[0083] [Table 2]

[0084] [Table 3]

[0085] Next, the production methods of the polymers (P) of Examples 1 to 11 and Comparative Examples 1 and 2 will be described below.

[0086] (Synthesis Example 1) First, the polymer (P) of Example 1 was produced as follows.

[0087] Specifically, 190.62 g of tap water, 63.71 g of a compound obtained by adding 50 moles of EO (ethylene oxide) to 1 mole of 7-octen-1-ol, and 95.56 g of a compound obtained by adding 50 moles of EO (ethylene oxide) to 1 mole of 3-methyl-3-buten-1-ol were prepared. These were then charged into a reactor equipped with a thermometer, a stirrer, a dropping funnel, and a nitrogen inlet tube, and dissolved uniformly while stirring. The atmosphere inside the reactor was then replaced with nitrogen, and the temperature of the reaction system was maintained at 65°C using a hot water bath.

[0088] Next, an aqueous solution prepared by uniformly dissolving 1.00 g of 30% hydrogen peroxide in 13.27 g of ion-exchanged water was added dropwise to the reaction system over 3 hours. Simultaneously, an aqueous solution prepared by uniformly dissolving 13.28 g of acrylic acid in 31.00 g of tap water was added dropwise to the reaction system over 3 hours. At the same time, an aqueous solution prepared by dissolving 0.62 g of L-ascorbic acid and 1.02 g of 3-mercaptopropionic acid in 12.27 g of tap water was added dropwise to the reaction system over 3.5 hours. The temperature of the reaction system was then maintained at 65°C for 1 hour to complete the polymerization reaction.

[0089] Thereafter, a 30% aqueous solution of sodium hydroxide was added to the reaction system so that the pH became 8, and the concentration was adjusted with tap water to obtain a 35% aqueous solution of the reaction mixture containing the polymer (P).

[0090] (Other synthesis examples) Polymer (P) was produced in the same manner as in Synthesis Example 1, except that the raw materials and reagents were changed so that the types and content ratios (mass%) of structural units 1 to 3 were as shown in Table 4, thereby obtaining polymers (P) of Examples 2 to 11 and Comparative Examples 1 and 2.

[0091] (Method for measuring mass average molecular weight) The reaction mixture obtained in each synthesis example was analyzed by gel permeation chromatography (GPC) under the following measurement conditions. The mass average molecular weights obtained as analysis results are shown in Table 4.

[0092] <Measurement conditions> Apparatus: Shodex GPC-101 (Showa Denko) Column: OHpak SB-G + SB-804M HQ + SB-802.5M HQ (Showa Denko) Detector: Differential refractometer (RI) Eluent: 50mM sodium nitrate aqueous solution Flow rate: 0.7mL / min Column temperature: 40℃ Sample concentration: Eluent solution with a sample concentration of 0.5% by weight Standard materials: polyethylene oxide, polyethylene glycol (Agilent Technologies)

[0093] (Method for measuring unreacted ether compounds (HPLC)) The reaction mixture was analyzed by high performance liquid chromatography (HPLC) under the following measurement conditions. Equipment: Prominence (Shimadzu Corporation) Column: Synergi 4 μm Hydro-RP 80A (Phenomenex) Detector: Differential refractometer (RI) Eluent: acetonitrile / 0.1% phosphate ion-exchange aqueous solution = 70 / 30 (volume %) Flow rate: 1.0ml / min Column temperature: 55℃ Sample concentration: Eluent solution with a sample concentration of 1.0 wt%

[0094] (Dispersant for hydraulic composition) The amount of the compound that forms the structural unit (1) and the structural unit (2) (i.e., unreacted ether compound) contained in the resulting reaction mixture was measured by high performance liquid chromatography (HPLC analysis).

[0095] Thereafter, the ether compound (A) was added to make up for the shortage so that the blending amount of the ether compound (A) was as shown in Table 4. Thereafter, the mixture was diluted with tap water to prepare a 20% aqueous solution of the dispersant for hydraulic compositions.

[0096] [Table 4]

[0097] In Table 4, "(A) / (P)" indicates the mass ratio (A / P) of the ether compound (A) to the polymer (P).

[0098] The ether compounds (A) (A1-1 to A1-8, A2-1 to A2-4, A3-1 to A3-4) are shown in the following Table 5. In Table 5, EO represents ethylene oxide, and PO represents propylene oxide.

[0099] [Table 5]

[0100] (2) Hydraulic composition: Next, concrete compositions (hydraulic compositions) were prepared using each of the prepared dispersants for hydraulic compositions.

[0101] Specifically, a forced twin-shaft mixer with a nominal capacity of 55 L was used to mix the mixture for 90 seconds, and 30 L of concrete composition was prepared.

[0102] In the prepared concrete composition, the air content was adjusted by adding 0.001% by mass of an antifoaming agent (product name AFK-2, manufactured by Takemoto Yushi) based on the mass of cement (C). The target slump flow was 600±50 mm, and the target air content was 2.0% or less. Each dispersant and antifoaming agent was used as part of the water.

[0103] [Table 6]

[0104] In Table 6, "W" indicates Gamagori City tap water, and "C" indicates ordinary Portland cement (an equal mixture of Taiheiyo Cement, UBE Mitsubishi Cement, and Sumitomo Osaka Cement), density = 3.16 g / cm 3 ), and "S" indicates the Oigawa River basin land sand (density = 2.55 g / cm 3 ), and "G" indicates crushed stone from Okazaki (density = 2.66 g / cm 3 ) "s / a" indicates the fine aggregate ratio.

[0105] [Slump flow (cm)] The concrete composition immediately after mixing was measured in accordance with JIS A 1150. The measurement results are shown in Table 7.

[0106] [Air volume (volume%)] The air content of the concrete composition immediately after mixing was measured in accordance with JIS A 1128. The measurement results are shown in Table 7.

[0107] (Dispersion performance) [Addition rate of dispersant for hydraulic composition (%)] The dispersing performance of the dispersant for hydraulic compositions was evaluated based on the addition rate of the dispersant for hydraulic compositions. The evaluation was carried out according to the following evaluation criteria (levels). The results are shown in Table 7. S: When the addition rate is less than 0.16% A: When the additive rate is 0.16% or more and less than 0.20% B: Addition rate is 0.20% or more and less than 0.25% C: When the addition rate is 0.25% or more

[0108] (viscosity) [500mm flow arrival time (sec)] Immediately after mixing, the concrete composition was measured for slump flow in accordance with JIS A 1150 and simultaneously for 500 mm flow time (seconds) in accordance with Appendix JA. The results are shown in Table 7.

[0109] The 500 mm flow reaching time (seconds) was evaluated according to the following evaluation criteria (levels). S: Less than 7 seconds A: More than 7 seconds and less than 7.5 seconds B: 7.5 seconds or more and less than 8.0 seconds C: If it is 8.0 seconds or more

[0110] [Table 7]

[0111] (result) As shown in Table 7, the dispersant for hydraulic compositions of this example has dispersing properties, and further, it is found that the viscosity of the hydraulic composition to which the dispersant for hydraulic compositions of this example is added is reduced. [Industrial Applicability]

[0112] The hydraulic composition dispersant of the present invention can be used as a dispersant for hydraulic compositions by adding it to the hydraulic composition. The hydraulic composition of the present invention can be used to prepare hardened hydraulic compositions such as hardened mortar and hardened concrete.

Claims

1. The polymer (P) contains a structural unit (1) formed from a compound represented by the following general formula (1), a structural unit (2) formed from a compound represented by the following general formula (2), and a structural unit (3) formed from at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, and salts thereof: the polymer (P) has a mass average molecular weight of 8,000 to 500,000; The polymer (P) contains 10 to 49 mass% of the structural unit (1), 30 to 89 mass% of the structural unit (2), and 1 to 25 mass% of the structural unit (3) converted into a sodium salt, when the total mass proportions of the structural unit (1), the structural unit (2), and the structural unit (3) converted into a sodium salt is taken as 100 mass%. 【Chemical 1】 (In general formula (1), X １ is an alkenyl group having 6 to 18 carbon atoms, and A １ O is an alkyleneoxy group having 2 to 4 carbon atoms, m is a number from 5 to 150, and Y １ is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms. 【Chemistry 2】 (In general formula (2), X ２ is an alkenyl group having 2 to 5 carbon atoms or an unsaturated acyl group having 3 to 4 carbon atoms, and A ２ O is an alkyleneoxy group having 2 to 4 carbon atoms, n is a number from 5 to 150, and Y ２ is a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms.

2. 2. The dispersant for hydraulic compositions according to claim 1, wherein the polymer (P) has a mass ratio of the structural unit (2) greater than a mass ratio of the structural unit (1).

3. In the general formula (2), X ２ The dispersant for hydraulic compositions according to claim 1, wherein is an alkenyl group having 2 to 5 carbon atoms.

4. The composition further contains an ether compound (A) which is a compound in which 1 to 500 moles of an alkylene oxide having 2 to 4 carbon atoms are added to 1 mole of a monohydric to tetrahydric aliphatic alcohol having 2 to 24 carbon atoms, 2. The dispersant for hydraulic compositions according to claim 1, wherein a mass ratio (A / P) of the ether compound (A) to the polymer (P) is 0.01 to 0.

25.

5. A hydraulic composition comprising a hydraulic binder, water, and the dispersant for hydraulic compositions according to any one of claims 1 to 4.

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