Dispersants and hydrohardening agents for hydraulic components

Abstract

The present invention provides a dispersant for hydraulic compositions that has dispersion properties and can reduce the viscosity of hydraulic compositions. [Solution] A dispersant for hydraulic compositions, characterized in that it contains a polymer (P) having a constituent unit (1) formed from a compound represented by general formula (1), a constituent unit (2) formed from a compound represented by general formula (2), and a constituent 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] This invention relates to a dispersant for hydraulic compositions and hydraulic compositions. More specifically, it relates to a dispersant for hydraulic compositions and hydraulic compositions that can reduce the viscosity of hydraulic compositions while having good dispersion 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] Examples of dispersants for this hydraulic composition 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 used that were not previously actively utilized (inferior quality aggregates) is increasing. It is known that hydraulic compositions using such aggregates (inferior quality aggregates compared to river sand, etc.) become highly viscous even at the usual water-to-binder ratio (W / B), resulting in poor workability.

[0005] Given this situation, methods for reducing the viscosity of hydraulic compositions (water-reducing agents, admixtures) have been reported, such as in Patent Documents 2 and 3. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2014-125366 [Patent Document 2] Chinese Patent Application Publication No. 115010875 Specification [Patent Document 3] Chinese Patent Application Publication No. 115960320 Specification [Overview of the project] [Problems that the invention aims to solve]

[0007] However, the water-reducing agent described in Patent Document 2 and the admixture described in Patent Document 3 were not yet sufficiently effective in reducing the viscosity of the hydraulic composition, and there was room for further improvement.

[0008] In other words, there was a need for the development of a dispersant (a dispersant for hydraulic compositions) that could further reduce the viscosity of hydraulic compositions (even if aggregates of lower quality than river sand, etc., were used).

[0009] In view of the above circumstances, the present invention aims to provide a dispersant for hydraulic compositions that can reduce the viscosity of hydraulic compositions while having good dispersion performance. [Means for solving the problem]

[0010] The inventors of the present invention have diligently researched the above problems and have found that they can be solved by using a predetermined polymer. According to the present invention, the following dispersant for hydraulic compositions and hydraulic compositions are provided.

[0011] [1] A polymer (P) having a constituent unit (1) formed from a compound represented by the following general formula (1), a constituent unit (2) formed from a compound represented by the following general formula (2), and a constituent 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 mass-average molecular weight of the polymer (P) is 8000~500000 dea the law of nature, The polymer (P) is composed of the following components: when the total mass percentage of the constituent units (1), (2), and (3) converted to sodium salts is 100% by mass, the constituent units (1) are 10-49% by mass, the constituent units (2) are 30-89% by mass, and the constituent units (3) converted to sodium salts are 1-25% by mass. A dispersant for hydraulic compositions characterized by the following:

[0012] [ka] (In general formula (1), X 1 This 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 the number of 1 and Y

[0013] [Chemical formula] (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 the number of 2 and Y

[0014] delete <000S0102>

[0015] 2 The dispersant for hydraulic composition according to [1] above, wherein the polymer (P) has a mass ratio of the constitutional unit (2) larger than the mass ratio of the constitutional unit (1).

[0016] 3 The dispersant for hydraulic composition according to [1] above, wherein in the general formula (2), X 2 is an alkenyl group having 2 to 5 carbon atoms.

[0017] 4 Further, it 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 monovalent to tetravalent aliphatic alcohol having 2 to 24 carbon atoms, and the value (A / P) of the mass ratio of the ether compound (A) to the polymer (P) is 0.01 to 0.25. The dispersant for hydraulic composition according to [1] above.

[0018] 5 A hydraulic composition characterized by containing a hydraulic binder, water, and the dispersant for hydraulic composition according to any one of [1] to 4 . ​​​​

Advantages of the Invention

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

[0020] The hydraulic composition of the present invention has the effect of reducing the viscosity by containing the dispersant for hydraulic compositions of the present invention.

Modes for Carrying Out the Invention

[0021] [[ID=*15]] 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 and improvements can be made to the following embodiments based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. In the following examples and the like, unless otherwise specified, % means mass %, and parts means parts by mass.

[0022] (1) Dispersant for hydraulic composition: 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. The mass average molecular weight of the polymer (P) teeth is 5,000 to 5,000,000. This can be done, and in the present invention, 8000 to 500000 is.

[0023]

Chemical formula

[0024] [ka] (In general formula (2), X 2 A is an alkenyl group having 2 to 5 carbon atoms, or an unsaturated acyl group having 3 to 4 carbon atoms. 2 O is an alkylene oxy group with 2 to 4 carbon atoms, and n is 5~150 The number is Y 2 (This refers to 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 maintaining good dispersion performance.

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

[0027] (1-1a) Constituent unit (1): The constituent unit (1) is a constituent unit formed from the compound represented by general formula (1), specifically, X in general formula (1). 1 This is an alkenyl group having 6 to 18 carbon atoms. Thus, polymer (P) is X in general formula (1). 1 This is a type of alkenyl group with a large number of carbon atoms.

[0028] As described above, X in general formula (1) 1 This 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, an alkenyl group is 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] Examples of alkenyl groups having 6 to 18 carbon atoms include hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, and octadecenyl groups.

[0031] A in general formula (1) 1 O is an alkylene oxy group having 2 to 4 carbon atoms (however, if multiple alkylene oxy groups are present, one type or two or more types may be used). Of these, an alkylene oxy group having 2 carbon atoms is preferred.

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

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

[0034] (1-1b) Constituent units (2): The constituent unit (2) is a constituent unit formed from a compound represented by general formula (2). By containing this constituent unit (2) in addition to the above-mentioned constituent unit (1), the polymer (P) can exhibit good dispersion performance in a dispersant for hydraulic compositions while further reducing the viscosity of the hydraulic composition.

[0035] X in general formula (2) 2This is 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] Examples of alkenyl groups having 2 to 5 carbon atoms include vinyl, allyl, butenyl, methallyl, pentenyl, 3-methyl-2-butenyl, and 3-methyl-3-butenyl groups.

[0037] Examples of unsaturated acyl groups with 3 to 4 carbon atoms include acryloyl groups, methacryloyl groups, and crotonoyl groups.

[0038] A in general formula (2) 2 O is an alkylene oxy group having 2 to 4 carbon atoms (however, if multiple alkylene oxy groups are present, one type or two or more types may be used). Of these, an alkylene oxy group having 2 carbon atoms is preferred.

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

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

[0041] (1-1c) Constituent units (3): The constituent unit (3) is 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 further containing such constituent unit (3) in addition to the above constituent units (1) and (2), polymer (P) can exhibit good dispersion performance in a dispersant for hydraulic compositions while further reducing the viscosity of the hydraulic composition.

[0042] The constituent unit (3) preferably contains at least acrylic acid or a salt thereof. This improves dispersion performance and further reduces the viscosity of the hydraulic composition.

[0043] (Mass ratio of constituent units (1) to (3)) Preferably, when the total mass percentage of constituent unit (1), constituent unit (2), and constituent unit (3) converted to sodium salt is taken as 100% by mass, the polymer (P) has a mass percentage of 1 to 98% by mass for constituent unit (1), 1 to 98% by mass for constituent unit (2), and 1 to 50% by mass for constituent unit (3) converted to sodium salt. Furthermore, it is more preferable that these mass percentages are 1 to 90% by mass for constituent unit (1), 1 to 90% by mass for constituent unit (2), and 1 to 40% by mass for constituent unit (3) converted to sodium salt, and particularly preferable that they are 10 to 45% by mass for constituent unit (1), 30 to 89% by mass for constituent unit (2), and 1 to 25% by mass for constituent unit (3) converted to sodium salt. By using the above mass percentages, the polymer (P) can exhibit good dispersion performance in a dispersant for hydraulic compositions while further reducing the viscosity of the hydraulic composition. In the present invention, the polymer (P) has a mass ratio of 10 to 49% by mass for constituent unit (1), 30 to 89% by mass for constituent unit (2), and 1 to 25% by mass for constituent unit (3) converted to sodium salt, with the total mass ratio of constituent unit (1), 2, and sodium salt converted to sodium salt being 1 to 25% by mass.

[0044] It is preferable that the polymer (P) has a mass ratio of constituent unit (2) that is greater than the mass ratio of constituent unit (1). By doing so, the polymer (P) can exhibit good dispersion performance in a dispersant for hydraulic compositions while further reducing the viscosity of the hydraulic composition.

[0045] Furthermore, the sodium salt conversion in "Constituent Unit (3) converted to sodium salt equivalent" can be carried out as follows: That is, all unsaturated carboxylic acids and their salts in constituent unit (3) are converted as if they were all sodium salts of unsaturated carboxylic acids. For example, all constituent units formed from acrylic acid are converted as constituent units formed from sodium acrylate, and all constituent units formed from maleic acid and maleic anhydride are converted as constituent units formed from disodium maleate.

[0046] (1-1d) Other structural units: Polymer (P) may have other constituent units in addition to the above constituent units (1) to (3). Examples of such other constituent units include those formed from compounds such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, alkyl (meth)acrylate, (meth)allyl sulfonic acid (salt), (meth)acrylamide, styrene, vinyl acetate, allyl sulfonate, and methallyl sulfonate.

[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 5,000,000. By having such a mass-average molecular weight, it is possible to reduce the viscosity of the hydraulic composition while providing good dispersion performance for the dispersant for the hydraulic composition.

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

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

[0050] (1-1e) Method for synthesizing polymer (P): The polymer (P) can be synthesized by conventionally known methods. Conventionally known methods include radical polymerization using water as the solvent, radical polymerization using organic solvents as the solvent, and solvent-free radical polymerization.

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

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

[0053] Furthermore, a chain transfer agent can be used to set the mass-average molecular weight of the resulting polymer (P) within a desired range.

[0054] In polymerization reactions, polymerization conditions such as polymerization temperature are appropriately determined by the polymerization method, solvent, polymerization initiator, and chain transfer agent used. However, the polymerization temperature is preferably 0°C or higher at the lower limit and 150°C or lower at the upper limit. More preferably 30°C or higher at the lower limit, and even more preferably 50°C or higher. Furthermore, the upper limit is more preferably 120°C or lower, and even more preferably 100°C or lower.

[0055] (1-2) Ether compounds (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 an alkylene oxide having 2 to 4 carbon atoms to 1 mole of a 1 to 4 valent aliphatic alcohol having 2 to 24 carbon atoms, and in this case, it is preferable that the mass ratio (A / P) of the ether compound (A) to the polymer (P) is 0.01 to 0.25. By satisfying these conditions, high dispersion performance can be achieved, and the viscosity of the hydraulic composition can be reduced.

[0056] Furthermore, the ether compound (A) preferably contains a compound obtained by adding 1 to 500 moles of alkylene oxide having 2 to 4 carbon atoms to 1 mole of monovalent 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% by mass or more, and more preferably 80% by mass or more. By satisfying these conditions, dispersion performance can be improved and the viscosity of the hydraulic composition can be further reduced.

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

[0058] The ether compound (A) can be the unreacted product from the synthesis reaction of the polymer (P). Alternatively, ether compound (A) may be added separately so that the ratio "A / P" falls within the predetermined range.

[0059] Here, when using unreacted material (unreacted ether compound) from the synthesis reaction of polymer (P) as ether compound (A) (specifically, as part of ether compound (A)), in order to satisfy the above A / P ratio, the synthesis must be carried out so that the amount of unreacted material (unreacted ether compound) from the synthesis reaction of polymer (P) does not exceed the upper limit of A / P. To achieve this, a compound that forms constituent unit (1), a compound that forms constituent unit (2), and a compound that forms constituent unit (3) with sufficient purity is used, and polymer (P) is obtained by polymerization using an appropriate method.

[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 retarders consisting of sugars, oxycarboxylates, etc., dispersing components consisting of sodium ligninsulfonate, etc., air-enhancing agents consisting of anionic surfactants, etc., defoaming agents consisting of oxyalkylene compounds, etc., curing accelerators consisting of alkanolamines, etc., shrinkage reducing agents consisting of polyoxyalkylene alkyl ethers, etc., thickeners consisting of cellulose ether compounds, etc., preservatives consisting of isothiazolinone compounds, etc., rust inhibitors consisting of nitrites, etc.

[0062] Furthermore, the other dispersant components may be used individually or in combination of two or more.

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

[0064] Furthermore, since ether compounds (A) (i.e., compounds that form constituent unit (1)) are used as raw materials for polymer (P), unreacted ether compounds (A) may remain in the reaction solution after the synthesis reaction of polymer (P). In this case, the reaction solution containing the unreacted ether compounds (A) can be used as is as a dispersant for hydraulic compositions.

[0065] Furthermore, if the mass ratio of the ether compound (A) to the polymer (P) (A / P) is to be between 0.01 and 0.25, the ether compound (A) can be further added as needed to satisfy this desired A / P (mass ratio of the ether compound (A) to the polymer (P)) to create a dispersant for hydraulic compositions.

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

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

[0068] Such hydraulic compositions have reduced viscosity due to the inclusion of the hydraulic composition dispersant 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, rapid-hardening 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. Furthermore, examples include various types of gypsum such as anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum, and powders with latent hydraulic properties, such as a combination of blast furnace slag fine powder and calcium hydroxide, combined with an alkaline stimulant.

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

[0071] (2-2) Dispersant for hydraulic compositions: In the hydraulic composition of the present invention, there are no particular restrictions on the content ratio of the dispersant for the hydraulic composition of the present invention, and it can be set as appropriate. For example, the content ratio of the dispersant for the hydraulic composition 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 hydraulic binder.

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

[0073] Examples of fine aggregates include river sand, mountain sand, land sand, sea sand, silica sand, crushed sand, and various slag aggregates, but they may also contain fine particles such as clay.

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

[0075] (2-4) Other compositional components: The hydraulic composition of the present invention may further contain other compositional components as appropriate, within a range that does not impair its effectiveness. Examples of such other compositional components include: a setting retarder consisting of sugars or oxycarboxylates; various water-reducing agents; an AE agent consisting of anionic surfactants; an antifoaming agent consisting of oxyalkylene compounds; a curing accelerator consisting of alkanolamines; a shrinkage reducing agent consisting of polyoxyalkylene alkyl ethers; a thickener consisting of cellulose ether compounds; a preservative consisting of isothiazolinone compounds; and a rust inhibitor consisting of nitrites.

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

[0077] The hydraulic composition of the present invention can appropriately adopt conventionally known ratios for the ratio of water to hydraulic binder (water / binder ratio), for example, it can be 20 to 70% by mass.

[0078] (3) Cured product of hydraulic composition: The hydraulic composition of the present invention can be hardened to form a hardened product. Specifically, this hardened product may be hardened mortar (hardened mortar), hardened concrete (hardened concrete), etc.

[0079] A hardened body of a hydraulic composition can be produced by conventionally known methods. Specifically, this can be done by filling a mold or the like with the hydraulic composition and curing it at room temperature or by heating it with steam. [Examples]

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

[0081] (Examples 1-11, Comparative Examples 1-2) (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 constituent units (1) to (3) of the polymer (P) used as a dispersant for the hydraulic compositions in Examples 1 to 11 and Comparative Examples 1 to 2 are shown in Tables 1 to 3 below. In Tables 1 to 3, the compounds that form each constituent unit (1) to (3) are indicated as "constituent unit (1) forming compound," etc. Note that a constituent unit (1) forming compound is a compound represented by general formula (1), and a constituent unit (2) forming compound is a compound represented by general formula (2).

[0082] [Table 1]

[0083] [Table 2]

[0084] [Table 3]

[0085] Next, the methods for producing each polymer (P) in Examples 1 to 11 and Comparative Examples 1 to 2 will be described below.

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

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

[0088] Next, an aqueous solution prepared by uniformly dissolving 1.00 g of 30% hydrogen peroxide solution in 13.27 g of deionized 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. After that, the temperature of the reaction system was maintained at 65°C for 1 hour to complete the polymerization reaction.

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

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

[0091] (Method for measuring mass-average molecular weight) The reaction mixtures obtained in each synthesis were analyzed by gel permeation chromatography (GPC) under the following measurement conditions. The resulting mass-average molecular weights are shown in Table 4.

[0092] <Measurement conditions> Equipment: Shodex GPC-101 (manufactured by Showa Denko Corporation) Columns: OHpak SB-G + SB-804M HQ + SB-802.5M HQ (manufactured by Showa Denko Corporation) Detector: Differential refractometer (RI) Eluent: 50 mM 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 substances: Polyethylene oxide, polyethylene glycol (manufactured by 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 (manufactured by Shimadzu Corporation) Column: Synergi 4μm Hydro-RP 80A (manufactured by Phenomenex) Detector: Differential refractometer (RI) Eluent: Acetonitrile / 0.1% phosphate 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% by weight.

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

[0095] Subsequently, the remaining amount of ether compound (A) was added to achieve the proportion of ether compound (A) shown in Table 4. Then, it 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 Table 5 below. 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 55L was used, and the mixture was kneaded for 90 seconds to prepare 30L of concrete composition.

[0102] In the prepared concrete composition, the air content was adjusted by using 0.001% by mass of an antifoaming agent (product name AFK-2, manufactured by Takemoto Oil Co., Ltd.) relative to the mass (C) of cement. 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 (equal parts mixture of Taiheiyo Cement, UBE Mitsubishi Cement, and Sumitomo Osaka Cement), density = 3.16 g / cm³. 3 ) indicates that "S" represents the terrestrial sand of the Oigawa River system (density = 2.55 g / cm³). 3 ) indicates that "G" is crushed stone from Okazaki (density = 2.66 g / cm³). 3 This indicates the ratio of fine aggregate. "s / a" indicates the ratio of fine aggregate.

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

[0107] (Dispersion performance) [Addition rate (%) of dispersant for hydraulic compositions] The dispersion performance of this hydraulic dispersant was evaluated based on its addition ratio. The evaluation was performed 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 addition rate is 0.16% or more and less than 0.20% B: When the addition rate is 0.20% or more and less than 0.25% C: When the addition rate is 0.25% or higher

[0108] (viscosity) [Time to reach 500mm flow (seconds)] For the concrete composition immediately after mixing, the slump flow was measured in accordance with JIS A 1150, and simultaneously, the time (seconds) to reach a 500 mm flow was measured in accordance with Annex JA. The results are shown in Table 7.

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

[0110] [Table 7]

[0111] (result) As shown in Table 7, the dispersant for hydraulic compositions in this embodiment has dispersion properties, and furthermore, the viscosity of the hydraulic composition to which the dispersant for hydraulic compositions in this embodiment is added is reduced. [Industrial applicability]

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

Claims

1. A polymer (P) having a constituent unit (1) formed from a compound represented by the following general formula (1), a constituent unit (2) formed from a compound represented by the following general formula (2), and a constituent 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, A dispersant for hydraulic compositions, characterized in that the mass-average molecular weight of the polymer (P) is 5,000 to 5,000,000. 【Chemistry 1】 (In general formula (1), X １ A is an alkenyl group having 6 to 18 carbon atoms. １ O is an alkylene oxy group having 2 to 4 carbon atoms, m is a number from 1 to 500, and Y １ (This refers to a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms.) 【Chemistry 2】 (In general formula (2), X ２ A is an alkenyl group having 2 to 5 carbon atoms, or an unsaturated acyl group having 3 to 4 carbon atoms. ２ O is an alkylene oxy group having 2 to 4 carbon atoms, n is a number from 1 to 500, and Y ２ (This refers to a hydrogen atom or a hydrocarbon group having 1 to 24 carbon atoms.)

2. The dispersant for hydraulic compositions according to claim 1, wherein the polymer (P) has a mass ratio of 1 to 98% by mass for the structural unit (1), the structural unit (2), and the structural unit (3) converted to a sodium salt, when the total mass ratio of the structural unit (1), the structural unit (2), and the structural unit (3) converted to a sodium salt is 100% by mass.

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

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

5. Furthermore, it 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 1 to 4 valent aliphatic alcohol having 2 to 24 carbon atoms. The dispersant for hydraulic compositions according to claim 1, wherein the mass ratio (A / P) of the ether compound (A) to the polymer (P) is 0.01 to 0.

25.

6. A hydraulic composition characterized by containing a hydraulic binder, water, and a dispersant for hydraulic compositions according to any one of claims 1 to 5.

Images