Dispersant for fine particles

Abstract

To provide a dispersant for fine particles capable of dispersing fine particles in an aqueous dispersion medium and obtaining an aqueous dispersion which maintains its dispersion state with the elapse of time (high dispersion stability with time).SOLUTION: A dispersant for fine particles is used for dispersing fine particles, comprising an organophosphate ester (A) which contains at least one selected from the group consisting of an organophosphate ester P1 represented by general formula (1), an organophosphate ester P2 represented by general formula (2), and an organophosphate ester P3 represented by general formula (3).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a dispersant for fine particles. More specifically, the present invention relates to a dispersant for fine particles that can disperse fine particles in an aqueous dispersion medium and obtain an aqueous dispersion in which the dispersed state is maintained over time (high dispersion stability over time). [Background technology]

[0002] BACKGROUND ART Inorganic fine particles, organic fine particles, or composite fine particles of these have been used in various fields such as cement and paint, and new fine particles are also being developed.

[0003] On the other hand, such fine particles have a problem in that the primary particles tend to aggregate to form secondary particles, making it difficult for the fine particles to exhibit their inherent properties.

[0004] For this reason, it is known to use a dispersant that can continuously and stably disperse the primary particles of the fine particles (see, for example, Patent Documents 1 and 2).

[0005] More specifically, it is known to use fine particles of calcium carbonate as a cement setting accelerator, but if such fine particles are added as they are when mixing mortar or concrete at a manufacturing plant, they will not be uniformly dispersed after a short period of mixing, and some of them will aggregate to form agglomerates (secondary particles), resulting in insufficient acceleration effects. For this reason, it is known to use an aqueous dispersion in which the fine particles are dispersed with a dispersant. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2018-500427 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-166156 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the dispersant described in Patent Document 1 did not have sufficient dispersion stability over time (i.e., did not have sufficient long-term storage stability). Also, the dispersant described in Patent Document 2 exhibits dispersion performance and has continuous dispersion stability, but there is room for further improvement.

[0008] In view of the above-mentioned circumstances, the present invention aims to provide a dispersant for fine particles that can disperse fine particles in an aqueous dispersion medium and obtain an aqueous dispersion in which the dispersed state is maintained over time (high dispersion stability over time). [Means for solving the problem]

[0009] As a result of intensive research aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by including a specific organic phosphate ester (A). According to the present invention, the following dispersant for fine particles is provided.

[0010] [1] A dispersant for dispersing fine particles, Contains the following organic phosphate ester (A): the fine particles are at least one fine particle selected from the group consisting of silica, aluminum oxide, calcium carbonate, titanium oxide, and calcium hydroxide; In P nuclear NMR measurement of the organic phosphate ester (A) pretreated by alkaline overneutralization, when the total of the P nuclear NMR integral ratios attributable to the organic phosphate ester P1 represented by the following general formula (1), the organic phosphate ester P2 represented by the following general formula (2), and the organic phosphate ester P3 represented by the following general formula (3) is taken as 100%, A dispersant for fine particles, characterized in that the P nucleus NMR integral ratio attributable to an organic phosphate ester P1 represented by the following general formula (1) is 50 to 99%. Organic phosphate ester (A): An organic phosphate ester P1 represented by the following general formula (1), an organic phosphate ester P2 represented by the following general formula (2), and an organic phosphate ester P3 represented by the following general formula (3): Both It includes:

[0011] [ka] (In general formula (1), R 1 is a styrenated phenyl group having 14 to 30 carbon atoms. 1 O is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type may be used alone or two or more types may be used). n1 is A 1 is the average number of moles of O added, and is a number from 1 to 150. 1 ,M 2 are each independently a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine.

[0012] [ka] (In the general formula (2), R 2 ,R 3 are each independently a styrenated phenyl group having 14 to 30 carbon atoms. 2 O,A 3 O each independently represents an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type may be used alone or two or more types may be used). 2 n3 is the average number of moles of O added, and is a number from 1 to 150. 3 is the average number of moles of O added, and is a number from 1 to 150. 3 is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine.

[0013] [ka] (In the general formula (3), R 4 ,R5 are each independently a styrenated phenyl group having 14 to 30 carbon atoms. 4 O,A 5 O each independently represents an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type may be used alone or two or more types may be used). 4 n5 is the average number of moles of O added, and is a number from 1 to 150. 5 is the average number of moles of O added, and is a number from 1 to 150. 4 is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine. r is an integer of 2 or 3.

[0014] [2] In the general formulas (1) to (3), A 1 O~A 5 The dispersant for fine particles according to [1] above, wherein each O is independently composed of 50 mol % or more of polyoxyethylene units.

[0015] [3] The dispersant for fine particles according to the above [1] or [2], wherein in the above general formulae (1) to (3), n1 to n5 each independently represent an integer of 1 to 75.

[0016] (delete)

[0017] (delete)

[0018] (delete)

[0019] [ 4 ] The above [1] to [ 3 10. The dispersant for fine particles according to any one of the preceding claims. [Effects of the Invention]

[0020] The dispersant for fine particles of the present invention has the effect of being able to disperse fine particles in an aqueous dispersion medium and to obtain an aqueous dispersion in which the dispersed state is maintained over time (high dispersion stability over time). 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 fine particles: slight The particle dispersant is a dispersant for dispersing fine particles, and contains an organic phosphate ester (A) (hereinafter sometimes referred to as "component A") that includes at least one selected from the group consisting of an organic phosphate ester P1 represented by the following general formula (1), an organic phosphate ester P2 represented by the following general formula (2), and an organic phosphate ester P3 represented by the following general formula (3). In the dispersant for fine particles of the present invention, the organic phosphate ester (A) contains both an organic phosphate ester P1 represented by the following general formula (1), an organic phosphate ester P2 represented by the following general formula (2), and an organic phosphate ester P3 represented by the following general formula (3).

[0023] Such a dispersant for fine particles can disperse fine particles in an aqueous dispersion medium, and can provide an aqueous dispersion in which the dispersed state is maintained over time (high dispersion stability over time).

[0024] [ka] (In general formula (1), R 1 is a styrenated phenyl group having 14 to 30 carbon atoms. 1 O is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type may be used alone or two or more types may be used). n1 is A 1 is the average number of moles of O added, and is a number from 1 to 150.1 ,M 2 are each independently a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine.

[0025] [ka] (In the general formula (2), R 2 ,R 3 are each independently a styrenated phenyl group having 14 to 30 carbon atoms. 2 O,A 3 O each independently represents an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type may be used alone or two or more types may be used). 2 n3 is the average number of moles of O added, and is a number from 1 to 150. 3 is the average number of moles of O added, and is a number from 1 to 150. 3 is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine.

[0026] [ka] (In the general formula (3), R 4 ,R 5 are each independently a styrenated phenyl group having 14 to 30 carbon atoms. 4 O,A 5 O each independently represents an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type may be used alone or two or more types may be used). 4 n5 is the average number of moles of O added, and is a number from 1 to 150. 5 is the average number of moles of O added, and is a number from 1 to 150. 4 is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine. r is an integer of 2 or 3.

[0027] (1-1) Organic phosphate ester (A): The organic phosphate ester (A) contains at least one selected from the group consisting of an organic phosphate ester P1 represented by general formula (1), an organic phosphate ester P2 represented by general formula (2), and an organic phosphate ester P3 represented by general formula (3). In the present invention, the organic phosphate ester (A) includes an organic phosphate ester P1 represented by the following general formula (1), an organic phosphate ester P2 represented by the following general formula (2), and an organic phosphate ester P3 represented by the following general formula (3). Such an organic phosphate ester (A) can disperse fine particles well. It is also possible to obtain an aqueous dispersion in which the dispersed state of fine particles is maintained over time (high dispersion stability over time). Furthermore, by using an aqueous dispersion of fine particles for hydraulic compositions using a dispersant containing this organic phosphate ester (A) in a hydraulic composition, the compressive strength of the hardened product of the hydraulic composition, such as mortar or concrete, at an initial age (e.g., 16 hours, 24 hours) and at a medium- to long-term age (e.g., 28 days) can be improved.

[0028] In the general formulas (1) to (3), A 1 O~A 5 Preferably, O are each independently composed of 50 mol % or more of polyoxyethylene units, more preferably 75 mol % or more of polyoxyethylene units, which can further increase the dispersion stability of the microparticles contained in the microparticle aqueous dispersion.

[0029] In the general formulas (1) to (3), n1 to n5 are each independently preferably 1 to 75, and more preferably 1 to 50. This can further increase the dispersion stability of the microparticles contained in the microparticle aqueous dispersion.

[0030] (1-1a) Organic phosphate ester P1 represented by general formula (1): R 1 Specific examples of the styrenated phenyl group having 14 to 30 carbon atoms in the formula include a monostyrenated phenyl group, a distyrenated phenyl group, and a tristyrenated phenyl group.

[0031] In general formula (1), A 1O is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type or two or more types may be used). The constituent ratio of these oxyalkylene groups is not particularly limited, but as described above, those constituted by polyoxyethylene units (polyoxyethylene groups) are preferably 50 mol % or more, more preferably 75 mol % or more. Furthermore, when there are two or more types of oxyalkylene groups, they may be in the form of a random adduct, a block adduct, or an alternating adduct.

[0032] n1 is A 1 It is the average number of moles of O added, and is a number from 1 to 150. As described above, n1 is preferably a number from 1 to 75, and more preferably a number from 1 to 50.

[0033] M 1 ,M 2 are each independently a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine. Among these, a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), or an organic amine is preferred. In this specification, the "organic amine" in the general formulas (1) to (3) is in a state of forming a salt with a hydroxyl group.

[0034] Examples of the organic amine include primary amines, secondary amines, and tertiary amines.

[0035] (1-1b) Organic phosphate ester P2 represented by general formula (2): R 2 ,R 3 Specific examples of the styrenated phenyl group having 14 to 30 carbon atoms in the formula include a monostyrenated phenyl group, a distyrenated phenyl group, and a tristyrenated phenyl group.

[0036] A 2 O,A 3Each O is independently an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type or two or more types may be used). The constituent ratio of these oxyalkylene groups is not particularly limited, but as described above, those constituted by polyoxyethylene units (polyoxyethylene groups) are preferably 50 mol % or more, more preferably 75 mol % or more. Furthermore, when there are two or more types of oxyalkylene groups, they may be in the form of a random adduct, a block adduct, or an alternating adduct.

[0037] n2 is A 2 It is the average number of moles of O added, and is a number from 1 to 150. As described above, n2 is preferably a number from 1 to 75, and more preferably a number from 1 to 50.

[0038] n3 is A 3 It is the average number of moles of O added, and is a number from 1 to 150. As described above, n3 is preferably a number from 1 to 75, and more preferably a number from 1 to 50.

[0039] M 3 is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine. Among these, a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), or an organic amine is preferred.

[0040] (1-1c) Organic phosphate ester P3 represented by general formula (3): R 4 ,R 5 Specific examples of the styrenated phenyl group having 14 to 30 carbon atoms in the formula include a monostyrenated phenyl group, a distyrenated phenyl group, and a tristyrenated phenyl group.

[0041] A 4 O,A 5Each O is independently an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type or two or more types may be used). The constituent ratio of these oxyalkylene groups is not particularly limited, but as described above, those constituted by polyoxyethylene units (polyoxyethylene groups) are preferably 50 mol % or more, more preferably 75 mol % or more. Furthermore, when there are two or more types of oxyalkylene groups, they may be in the form of a random adduct, a block adduct, or an alternating adduct.

[0042] n4 is A 4 It is the average number of moles of O added, and is a number from 1 to 150. As described above, n4 is preferably a number from 1 to 75, and more preferably a number from 1 to 50.

[0043] n5 is A 5 It is the average number of moles of O added, and is a number from 1 to 150. As described above, n5 is preferably a number from 1 to 75, and more preferably a number from 1 to 50.

[0044] M 4 is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine. Among these, a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), or an organic amine is preferred.

[0045] r is an integer of 2 or 3.

[0046] (P nucleus NMR integral ratio) In the dispersant for fine particles of the present invention, when P nuclear NMR measurement of organophosphate ester (A) pretreated by alkaline overneutralization is performed, the P nuclear NMR integral ratio attributable to organophosphate ester P1 represented by general formula (1) satisfies 50 to 99%, when the sum of the P nuclear NMR integral ratios attributable to organophosphate ester P1 represented by general formula (1), organophosphate ester P2 represented by general formula (2), and organophosphate ester P3 represented by general formula (3) is taken as 100%. Furthermore, this P nuclear NMR integral ratio is preferably 55 to 99%, more preferably 60 to 99%.

[0047] Thus, when the organic phosphate ester (A) satisfies the specified conditions for the above-mentioned P nuclear NMR integral ratio, the dispersant for fine particles of the present invention can disperse fine particles even better in an aqueous dispersion medium, and an aqueous dispersion can be obtained in which the dispersed state is maintained for a long time (high dispersion stability over time).

[0048] Specifically, the P NMR integral ratio (%) attributable to the organic phosphate ester (A) can be calculated as follows: That is, an excess of KOH is added to each organic phosphate ester (A) to adjust the pH to 12 or higher (i.e., an alkaline over-neutralization pretreatment is performed), 31 Measurement is performed using P-NMR (for example, MERCURY plus NMR Spectrometer System, 300 MHz, manufactured by VALIAN). Then, calculation is performed using the obtained measurement values ​​according to the following formulas (a) to (c). The solvent used may be a mixed solvent of heavy water / tetrahydrofuran = 8 / 2 (volume ratio).

[0049]

number

[0050]

number

[0051]

number

[0052] In the above formulas (a) to (c), P-1, P-2, and P-3 are as shown below. P Compound 1: P nucleus NMR integral value assigned to organophosphate ester P1 represented by general formula (1) P Compound 2: P nucleus NMR integral value assigned to organophosphate ester P2 represented by general formula (2) P Compound 3: P nucleus NMR integral value assigned to organophosphate ester P3 represented by general formula (3)

[0053] The term "alkaline overneutralization pretreatment" refers to a pretreatment in which an excess amount of alkali is added to the organic phosphate ester (A). 31 In P-NMR measurements, when this "alkaline overneutralization pretreatment" is performed, the peaks assigned to the organic phosphate esters P1 to P3 can be clearly separated, and the P nucleus NMR integral ratios assigned to each compound can be calculated using the above formulas (a) to (c).

[0054] The alkali to be added is not particularly limited, and examples thereof include organic amines, hydroxides of alkali metals or alkaline earth metals, etc. The alkali may be the same as or different from the alkali used in synthesizing the organic phosphate ester (A).

[0055] Examples of organic amines include methylamine, dimethylamine, etc. Examples of hydroxides of alkali metals or alkaline earth metals include sodium hydroxide, potassium hydroxide, magnesium hydroxide, etc.

[0056] The blending ratio of the organic phosphate ester (A) is not particularly limited, and the organic phosphate ester (A) may be used as the dispersant for fine particles as it is (i.e., the blending ratio of the organic phosphate ester (A) is 100% by mass). Furthermore, the dispersant for fine particles of the present invention may further contain other constituents in addition to the organic phosphate ester (A).

[0057] Other constituents include, for example, monostyrenated phenol, distyrenated phenol, tristyrenated phenol, polyoxyethylene monostyrylphenyl ether, polyoxypropylene monostyrylphenyl ether, polyoxyethylene polyoxypropylene monostyrylphenyl ether, polyoxyethylene distyrylphenyl ether, polyoxypropylene distyrylphenyl ether, polyoxyethylene polyoxypropylene distyrylphenyl ether, polyoxyethylene tristyrylphenyl ether, polyoxypropylene tristyrylphenyl ether, polyoxyethylene polyoxypropylene tristyrylphenyl ether, inorganic phosphoric acid (salt), polyphosphoric acid (salt), polyoxyethylene surfactants (polyoxyethylene alkyl ethers, polyoxyethylene alkyl ethers), Examples of suitable olefin copolymers include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene fatty acid esters, etc.), alkyl sulfonic acids (salts), alkyl benzene sulfonic acids (salts), alkyl naphthalene sulfonic acids (salts), polyoxyethylene alkyl ether sulfonic acids (salts), alkyl sulfates (salts), alkyl sulfate esters (salts), higher alcohol sulfate esters (salts), polyoxyethylene alkyl phenyl ether sulfates (salts), alkyl phosphate esters (salts), polyoxyethylene alkyl ether phosphate esters (salts), polyoxyethylene alkyl phenyl ether phosphate esters (salts), polycarboxylic acids (salts), and naphthalene sulfonic acid formaldehyde condensates.

[0058] (Method for producing organic phosphate ester (A)) The organic phosphate ester (A) can be appropriately produced by a conventionally known method. For example, it can be produced by reacting various alcohols with diphosphorus pentoxide under heated and stirred conditions to obtain an organic phosphate ester compound, and then neutralizing the organic phosphate ester compound with an alkali such as potassium hydroxide, as necessary. In this synthesis method, the organic phosphate ester (A) is usually a mixture of an organic phosphate ester P1 represented by general formula (1), an organic phosphate ester P2 represented by general formula (2), and an organic phosphate ester P3 represented by general formula (3). The organic phosphate ester (A) may also be prepared by synthesizing the organic phosphate ester P1 represented by general formula (1), the organic phosphate ester P2 represented by general formula (2), and the organic phosphate ester P3 represented by general formula (3) separately and then mixing them together, without employing the above synthesis method.

[0059] (1-2) Fine particles: The dispersant for fine particles of the present invention is used to disperse fine particles, and an aqueous fine particle dispersion in which fine particles are dispersed can be obtained using the dispersant for fine particles of the present invention. The fine particles to be dispersed are not particularly limited and can be those used in various technical fields such as concrete and paint, and may be inorganic fine particles, organic fine particles, or composite fine particles of inorganic and organic fine particles.

[0060] Specifically, the fine particles include at least one fine particle selected from the group consisting of semi-metal oxides, metal oxides, metal carbonates, and metal hydroxides, and more specifically, silica, aluminum oxide, calcium carbonate, titanium oxide, calcium hydroxide, zirconia, zinc oxide, magnesium oxide, etc. Among these, in the present invention, at least one fine particle selected from the group consisting of silica, aluminum oxide, calcium carbonate, titanium oxide, and calcium hydroxide is preferred. the law of natureIt is more preferable that the fine particles are at least one selected from the group consisting of silica, aluminum oxide, and calcium carbonate. With such fine particles, the dispersing action of the organic phosphate ester (A) works more effectively, the fine particles can be dispersed well in the aqueous dispersion medium, and an aqueous dispersion in which the dispersed state is maintained for a long time (high dispersion stability over time) can be obtained.

[0061] The median diameter of the microparticles in the dispersion is not particularly limited, and can be 10 to 1000 nm, preferably 10 to 500 nm, and more preferably 10 to 250 nm. By adjusting the diameter within this range, the microparticles can be well dispersed in the aqueous dispersion medium, and an aqueous dispersion can be obtained in which the dispersed state is maintained over time (high dispersion stability over time). Note that this median diameter refers to the median diameter immediately after the preparation of the aqueous microparticle dispersion (specifically, within one hour after preparation).

[0062] The median diameter in this specification can be measured using a laser diffraction / scattering particle size distribution measuring device or the like.

[0063] In this specification, the term "median diameter" refers to the specific particle size at which, when a powder or granular material is divided into particles smaller than a specific particle size (aggregates of small particle sizes) and particles larger than the specific particle size (aggregates of large particle sizes), the aggregates of small particle sizes and the aggregates of large particle sizes are equal in amount (50% by volume each).

[0064] In the aqueous dispersion of fine particles in which fine particles are dispersed using the dispersant for fine particles of the present invention, there are no particular limitations on the blending ratio of the organic phosphate ester (A) and the fine particles.

[0065] The content of the organic phosphate ester (A) in the aqueous dispersion of fine particles can be, for example, 0.1 to 20.0 mass %, preferably 0.1 to 18.0 mass %, and more preferably 0.1 to 15.0 mass %. By setting the content within such a range, the dispersion stability of the contained fine particles can be further improved.

[0066] The blending ratio of the fine particles in the aqueous dispersion of fine particles can be, for example, 1.0 to 50.0% by mass, preferably 1.0 to 45.0% by mass, and more preferably 1.0 to 40.0% by mass. By setting the blending ratio in this range, the dispersion stability of the contained fine particles can be further improved.

[0067] The blending ratio of the organic phosphate ester (A) to the fine particles (i.e., the mass ratio of the organic phosphate ester (A) to the fine particles) is not particularly limited, but may be, for example, 0.01 to 1.00, preferably 0.03 to 0.80, and more preferably 0.05 to 0.50. By setting the blending ratio within such a range, the dispersion stability of the contained fine particles is further improved.

[0068] (1-3) Other components: The aqueous fine particle dispersion may further contain other components in addition to the organic phosphate ester (A) and the fine particles.

[0069] Examples of other constituent components include additives for hydraulic compositions such as water-reducing agents, air-entraining water-reducing agents, high-performance air-entraining water-reducing agents, air-entraining agents as air content adjusters, antifoaming agents, setting retarders, shrinkage-reducing agents, thickeners, hardening accelerators, preservatives, waterproofing agents, and rust inhibitors.

[0070] The content of other constituent components can be, for example, 0 to 50% by mass in terms of solid content in 100% by mass of the fine particle aqueous dispersion.

[0071] (2) Use of dispersants for fine particles: The dispersant for fine particles of the present invention can be used in various fields such as cosmetics, electronic materials, biotechnology, etc. in addition to the fields of cement, paint, etc., and specifically can be blended into hydraulic compositions such as cement and mortar.

[0072] (2-1) Hydraulic composition: The hydraulic composition can contain the dispersant for fine particles of the present invention. By using an aqueous microparticle dispersion containing the dispersant for fine particles of the present invention and fine particles, the hydraulic composition can be formed into a hardened product of the hydraulic composition, which has improved compressive strength at an early age (e.g., 16 hours, 24 hours) and at a medium to long term age (e.g., 28 days).

[0073] This hydraulic composition contains a binder, water, fine aggregate, coarse aggregate, etc., similar to conventionally known hydraulic compositions.

[0074] The content of the dispersant for fine particles of the present invention in the hydraulic composition is not particularly limited and can be set as appropriate, but the content of the dispersant for fine particles of the present invention can be, for example, 0.001 to 3.0 mass % in terms of solid content relative to 100 mass % of the binder.

[0075] Examples of 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.

[0076] Furthermore, various admixtures such as fly ash, ground granulated blast furnace slag, ground limestone, stone powder, silica fume, and expansive agents may be used in combination with the various cements mentioned above.

[0077] 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.

[0078] Examples of coarse aggregate include river gravel, mountain gravel, land gravel, crushed stone, various types of slag coarse aggregate, lightweight aggregate, and the like.

[0079] The hydraulic composition may further contain other components as appropriate within the range that does not impair the effect. Examples of such other components include a setting retarder composed of a sugar, an oxycarboxylate, or the like, a dispersing component composed of a lignin sulfonate, an air-entraining agent composed of an anionic surfactant, an antifoaming agent composed of an oxyalkylene compound, or the like, a hardening accelerator composed of an alkanolamine, a shrinkage reducer composed of a polyoxyalkylene alkyl ether, or the like, a thickener composed of a cellulose ether compound, an antiseptic composed of an isothiazolinone compound, or a rust inhibitor composed of a nitrite, or the like.

[0080] The content of other components can be, for example, 0 to 5 mass % in terms of solid content relative to 100 mass % of the binder.

[0081] The ratio of water to binder (water / binder ratio) of the hydraulic composition can be suitably selected from conventionally known ratios, and can be, for example, 25 to 70 mass %.

[0082] This hydraulic composition is filled into a formwork or the like and cured at room temperature or by heat curing with steam, whereby hardened concrete, mortar, etc. (hardened hydraulic composition product) can be obtained. [Example]

[0083] The present invention will be specifically described below based on examples, but the present invention is not limited to these examples.

[0084] First, the organic phosphate esters (A-1) to (A-18) and the organic phosphate esters (RA-3) to (RA-4), which are the organic phosphate ester (A), were produced as follows.

[0085] (Production Example 1) Synthesis of organic phosphate ester (A-1): (Synthesis of poly(12 mol)oxyethylene monostyrylphenyl ether) A pressure vessel equipped with a stirrer, pressure gauge, and thermometer was charged with 257.0 g of SP-F (trade name) manufactured by Sanko Co., Ltd., which contains monostyrenated phenol as its main component, and 1.0 g of potassium hydroxide. The reaction system was then heated to 120°C, after which the reaction system was depressurized and dehydrated for 1 hour. Subsequently, while maintaining the reaction system at 130±5°C, 687.2 g of ethylene oxide was added at a gauge pressure of 0.4 MPa over 6 hours. The temperature was maintained at 130±5°C for 1 hour, and the reaction was terminated. Neutralization was then carried out using Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.), followed by filtration to obtain poly(12 mol)oxyethylene monostyrylphenyl ether. Note that "SP-F (trade name) manufactured by Sanko Co., Ltd." contains styrenated phenols such as distyrenated phenol in addition to the main component, monostyrenated phenol. As described above, the styrenated phenol to be specifically used may contain a styrenated phenol compound as the main component and a styrenated phenol compound other than the main component (specifically, in the above case, a di- or tri-polystyrenated phenol compound).

[0086] (phosphorylation) Next, 215.9 g of the obtained poly(12 mol)oxyethylene monostyrylphenyl ether was charged into another reaction vessel and dehydrated at 120°C for 2 hours under conditions of 0.05 MPa or less, and then returned to atmospheric pressure. The temperature was then raised to 60±5°C, and 16.9 g of diphosphorus pentoxide was added over 0.5 hours with stirring. After aging for 3 hours at 80°C, 6.5 g of ion-exchanged water was added and aged for 0.5 hours. The aged reaction solution was then neutralized by adding 35.9 g of 48% aqueous potassium hydroxide solution dropwise at 50°C, and 224.9 g of ion-exchanged water was added and stirred to obtain a 50% aqueous solution of organic phosphate ester (A-1) (component A).

[0087] (Production Example 2) Synthesis of organic phosphate ester (A-4): (Synthesis of poly(12 mol)oxyethylene distyryl phenyl ether) A pressure vessel equipped with a stirrer, pressure gauge, and thermometer was charged with 363.9 g of DSP (trade name) manufactured by Yokkaichi Synthetic Co., Ltd., which contains distyrenated phenol as its main component, and 1.0 g of potassium hydroxide. The reaction system was then heated to 120°C, after which the reaction system was depressurized and dehydrated for 1 hour. Subsequently, while maintaining the reaction system at 130±5°C, 636.1 g of ethylene oxide was added at a gauge pressure of 0.4 MPa over 6 hours. The temperature was maintained at 130±5°C for 1 hour, and the reaction was terminated. Neutralization was then carried out using Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.), followed by filtration to obtain poly(12 mol)oxyethylene distyrylphenyl ether. Note that "DSP (trade name) manufactured by Yokkaichi Synthetic Co., Ltd." contains styrenated phenols such as monostyrenated phenol in addition to the main component, distyrenated phenol. As described above, the styrenated phenol to be specifically used may contain a styrenated phenol compound as the main component and a styrenated phenol compound other than the main component (specifically, in the above case, a mono-, tri-, or polystyrenated phenol compound).

[0088] (phosphorylation) Next, 219.1 g of the obtained poly(12 mol)oxyethylene distyrylphenyl ether was charged into another reaction vessel and dehydrated at 120°C for 2 hours under conditions of 0.05 MPa or less, and then returned to atmospheric pressure. The temperature was then raised to 60±5°C, and 13.4 g of diphosphorus pentoxide was added over 0.5 hours while stirring. After aging for 3 hours at 80°C, 6.6 g of ion-exchanged water was added and aged for 0.5 hours. The aged reaction solution was then neutralized by adding 36.5 g of 48% aqueous potassium hydroxide solution dropwise at 50°C, and 224.4 g of ion-exchanged water was added while stirring to obtain a 50% aqueous solution of organic phosphate ester (A-4) (component A).

[0089] (Production Example 3) Synthesis of organic phosphate ester (A-5): (Synthesis of poly(18 mol)oxyethylene tristyrylphenyl ether) A pressure vessel equipped with a stirrer, pressure gauge, and thermometer was charged with 339.0 g of TSP (trade name) manufactured by Sanko Co., Ltd., which contains tristyrenated phenol as its main component, and 1.0 g of potassium hydroxide. The reaction system was then heated to 120°C, after which the reaction system was depressurized and dehydrated for 1 hour. Subsequently, while maintaining the reaction system at 130±5°C, 661.0 g of ethylene oxide was added at a gauge pressure of 0.4 MPa over 6 hours. The temperature was maintained at 130±5°C for 1 hour, and the reaction was terminated. Neutralization was then carried out using Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.), followed by filtration to obtain poly(18 mol)oxyethylene tristyrylphenyl ether. Note that "TSP (trade name) manufactured by Sanko Co., Ltd." contains styrenated phenols such as monostyrenated phenol in addition to the main component, tristyrenated phenol. As described above, the styrenated phenol to be specifically used may contain a styrenated phenol compound as the main component and a styrenated phenol compound other than the main component (specifically, in the above case, a mono- or di-polystyrenated phenol compound).

[0090] (phosphorylation) Next, 218.0 g of the obtained poly(18 mol)oxyethylene tristyrylphenyl ether was charged into another reaction vessel and dehydrated at 120°C for 2 hours under conditions of 0.05 MPa or less, and then returned to atmospheric pressure. The temperature was then raised to 60±5°C, and 21.5 g of diphosphorus pentoxide was added over 0.5 hours with stirring. After aging for 3 hours at 80°C, 6.5 g of ion-exchanged water was added and aged for 0.5 hours. The aged reaction solution was then neutralized by adding 22.0 g of 48% aqueous potassium hydroxide solution dropwise at 50°C, and 232.0 g of ion-exchanged water was added and stirred to obtain a 50% aqueous solution of organic phosphate ester (A-5) (component A).

[0091] (Production Example 4) Synthesis of organic phosphate ester (A-18): (Synthesis of poly(16 mol)oxyethylene poly(4 mol)oxypropylene distyryl phenyl ether) A pressure vessel equipped with a stirrer, pressure gauge, and thermometer was charged with 244.0 g of DSP (trade name) manufactured by Yokkaichi Chemical Co., Ltd., which is primarily composed of distyrenated phenol, and 1.0 g of potassium hydroxide. The reaction system was then heated to 120°C, and the reaction system was then subjected to a reduced pressure and dehydration treatment for 1 hour. Subsequently, while maintaining the reaction system at 130±5°C, 568.6 g of ethylene oxide was added at a gauge pressure of 0.4 MPa over 6 hours. The mixture was then maintained at 130±5°C for 0.5 hours and aged. Then, 187.4 g of 1,2-propylene oxide was added at a gauge pressure of 0.4 MPa over 4 hours, and the mixture was maintained at 130±5°C for 1 hour to terminate the reaction. The mixture was then neutralized using Kyoward 600 (manufactured by Kyowa Chemical Industry Co., Ltd.) and filtered to obtain poly(16 mol)oxyethylene poly(4 mol)oxypropylene distyrylphenyl ether.

[0092] (phosphorylation) Next, 231.9 g of the obtained poly(16 mol)oxyethylene poly(4 mol)oxypropylene distyrylphenyl ether was charged into another reaction vessel and dehydrated at 120°C for 2 hours under conditions of 0.05 MPa or less, and then returned to atmospheric pressure. The temperature was then raised to 60±5°C, and 5.3 g of diphosphorus pentoxide was added over 0.5 hours while stirring. After aging for 3 hours at 80°C, 7.0 g of ion-exchanged water was added and aged for 0.5 hours. The aged reaction solution was then neutralized by adding 42.5 g of 30% aqueous sodium hydroxide solution dropwise at 50°C, and 213.2 g of ion-exchanged water was added while stirring to obtain a 50% aqueous solution of organic phosphate ester (A-18) (component A).

[0093] (Production Example 5) Synthesis of organic phosphate ester (RA-3): (Synthesis of poly(12 mol)oxyethylene phenyl ether) A pressure vessel equipped with a stirrer, pressure gauge, and thermometer was charged with 151.1 g of phenol and 1.0 g of potassium hydroxide. The reaction system was then heated to 120°C, and the reaction system was then subjected to a reduced pressure and dehydration treatment for 1 hour. Subsequently, while maintaining the reaction system at 130±5°C, 848.9 g of ethylene oxide was added at a gauge pressure of 0.4 MPa over 6 hours. The temperature was maintained at 130±5°C for 1 hour, and the reaction was terminated. The mixture was then neutralized using Kyoward 600 (Kyowa Chemical Industry Co., Ltd.) and filtered to obtain poly(12 mol)oxyethylene phenyl ether.

[0094] (phosphorylation) Next, 219.4 g of the obtained poly(12 mol)oxyethylene phenyl ether was charged into a separate reaction vessel and dehydrated at 120°C for 2 hours under conditions of 0.05 MPa or less, after which the pressure was returned to atmospheric pressure. The temperature was then raised to 60±5°C, and 20.0 g of diphosphorus pentoxide was added over 0.5 hours while stirring. After aging for 3 hours at 80°C, 6.6 g of ion-exchanged water was added and aged for 0.5 hours. The aged reaction solution was then neutralized by adding 22.0 g of 48% aqueous potassium hydroxide solution dropwise at 50°C, and 231.9 g of ion-exchanged water was added while stirring to obtain a 50% aqueous solution of organic phosphate ester (RA-3) (component A).

[0095] (Production Example 6) Synthesis of organic phosphate ester (RA-4): (Synthesis of poly(13 mol)oxyethylene monooleyl ether) A pressure vessel equipped with a stirrer, pressure gauge, and thermometer was charged with 318.9 g of oleyl alcohol and 1.0 g of potassium hydroxide. The reaction system was then heated to 120°C, and the reaction system was then subjected to a reduced pressure and dehydration treatment for 1 hour. Subsequently, while maintaining the reaction system at 130±5°C, 681.1 g of ethylene oxide was added at a gauge pressure of 0.4 MPa over 6 hours. The temperature was maintained at 130±5°C for 1 hour, and the reaction was terminated. The mixture was then neutralized using Kyoward 600 (Kyowa Chemical Industry Co., Ltd.) and filtered to obtain poly(13 mol)oxyethylene monooleyl ether.

[0096] (phosphorylation) Next, 224.3 g of the obtained poly(13 mol)oxyethylene monooleyl ether was charged into a separate reaction vessel and dehydrated at 120°C for 2 hours under conditions of 0.05 MPa or less, after which the pressure was returned to atmospheric pressure. The temperature was then raised to 60±5°C, and 15.1 g of diphosphorus pentoxide was added over 0.5 hours while stirring. After aging for 3 hours at 80°C, 6.7 g of ion-exchanged water was added and aged for 0.5 hours. The aged reaction solution was then neutralized by adding 22.0 g of 48% aqueous potassium hydroxide solution dropwise at 50°C, and 231.8 g of ion-exchanged water was added while stirring to obtain a 50% aqueous solution of organic phosphate ester (RA-4) (component A).

[0097] (Production Examples 7 to 20) Synthesis of organic phosphate esters (A-2) to (A-3) and (A-6) to (A-17): The organic phosphate esters (A-2) to (A-3) and (A-6) to (A-17) were each synthesized in the same manner as the synthesis of the organic phosphate ester (A-1), except that the type and charge ratio of the raw material polyether, the charge ratio of diphosphorus pentoxide, and the type of alkali used for neutralization were changed so as to obtain the component A shown in Table 1.

[0098] (Production Example 21) Synthesis of copolymer (RA-1) of α-methacryloyl-ω-methoxypoly(23 mol)oxyethylene and methacrylic acid: 75.2 g of ion-exchanged water, 167.1 g of α-methacryloyl-ω-methoxypoly(23 mol)oxyethylene, 22.8 g of methacrylic acid, and 1.7 g of 3-mercaptopropionic acid (molecular weight 106.1) as a chain transfer agent were charged into a reaction vessel and dissolved uniformly with stirring. The atmosphere was then replaced with nitrogen, and the temperature of the reaction system was maintained at 65°C in a hot water bath. Next, 27.5 g of a 10% aqueous solution of sodium persulfate was added dropwise over 4 hours. The mixture was then maintained at 65°C for 2 hours to complete the polymerization reaction. The pH of the reaction system was then adjusted to 6 by adding 30% aqueous sodium hydroxide, and the concentration was adjusted to 40% with ion-exchanged water to obtain a 40% aqueous solution of vinyl copolymer (RA-2). Analysis of this vinyl copolymer (RA-1) by gel permeation chromatography (GPC) revealed that the mass-average molecular weight was 30,000.

[0099] (mass average molecular weight) The weight average molecular weight of the synthesized copolymer (RA-1) of α-methacryloyl-ω-methoxypoly(23 mol)oxyethylene and methacrylic acid was measured using gel permeation chromatography (GPC) under the following conditions. <Measurement conditions> Apparatus: Shodex GPC-101 (Showa Denko) Column: OHpak SB-G + SB-806M HQ + SB-806M 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 mass Standard material: PEG / PEO (Agilent Technologies)

[0100] (P nuclear NMR integral ratio) A specific method for calculating the P NMR integral ratio (%) assigned to the organic phosphate ester (A) is shown below.

[0101] Each organic phosphate ester (A) was subjected to an alkaline over-neutralization pretreatment under the condition that excess KOH was added to the organic phosphate ester (A) to adjust the pH to 12 or higher (i.e., the organic phosphate ester (A) was subjected to an alkaline over-neutralization pretreatment). 31 The values ​​are calculated based on the following formulas (a) to (c) using the measured values ​​obtained by P-NMR (specifically, MERCURY plus NMR Spectrometer System, 300 MHz, manufactured by VALIAN). The solvent used was a mixed solvent of heavy water / tetrahydrofuran = 8 / 2 (volume ratio).

[0102]

number

[0103]

number

[0104]

number

[0105] In the above formulas (a) to (c), P-1, P-2, and P-3 are as shown below. P Compound 1: P nucleus NMR integral value assigned to organophosphate ester P1 represented by general formula (1) P Compound 2: P nucleus NMR integral value assigned to organophosphate ester P2 represented by general formula (2) P Compound 3: P nucleus NMR integral value assigned to organophosphate ester P3 represented by general formula (3)

[0106] Table 1 shows the calculated results of the P NMR integral ratio (%) assigned to the organic phosphate ester (A).

[0107] [Table 1]

[0108] In the "AO" column of Table 1, "addition form" indicates the addition form of two types of oxyalkylene groups (EO, PO), with "random" indicating a random adduct and "block" indicating a block adduct.

[0109] In Table 1, the poly(13 mol)oxyethylene monooleyl ether "RA-2" was the same as the poly(13 mol)oxyethylene monooleyl ether obtained in the synthesis of the organic phosphate ester (RA-4) in Production Example 6 described above.

[0110] (Example 1 13、15~ 18, 21~23, reference examples 14、 19 、 20, Comparative Examples 1 to 5) Next, an aqueous dispersion of fine particles was prepared using the synthesized dispersant for fine particles such as organic phosphate ester and each of the fine particles shown in Table 2 in the predetermined ratio shown in Table 3.

[0111] Specifically, each of the fine particles shown in Table 2, water, each of the organic phosphate esters (A) (dispersants for fine particles) shown in Table 1, and spherical zirconia beads with a diameter of 0.5 mm were added to a glass container and shaken for 1 hour using a paint shaker (manufactured by Toyo Seiki Seisakusho). However, for SP-22 shown in Table 3, the shaking time in the paint shaker was 30 minutes. The zirconia beads were used in an amount of 200% by mass relative to the dispersion liquid to be prepared. After shaking, the zirconia beads were removed using a wire mesh as a sieve to obtain each of the aqueous fine particle dispersions shown in Table 3. The paint shaker was operated under the condition of reciprocating motion with an amplitude of 650 to 750 revolutions per minute.

[0112] The thus obtained aqueous dispersion of fine particles was subjected to various measurements and evaluations as shown in Table 3. Specifically, the median diameter was measured and the dispersion stability was evaluated. The results are shown in Table 3.

[0113] The inorganic fine particles (B) (component B) were prepared using the following materials to prepare an aqueous fine particle dispersion (aqueous fine particle dispersion for hydraulic composition). P-1: NEOLIGHT SP (product name) manufactured by Takehara Chemical Industry Co., Ltd. P-2: AEROSIL 200 (trade name) manufactured by Nippon Aerosil Co., Ltd. P-3: AEROXIDE Alu C (trade name) manufactured by Nippon Aerosil Co., Ltd. P-4: AEROXIDE TiO2 P25 (trade name) manufactured by Nippon Aerosil Co., Ltd. P-5: Special grade reagent manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. RP-1: Techpolymer SBX-4 (product name) manufactured by Sekisui Plastics Co., Ltd.

[0114] (Median diameter measurement) The median diameter of each of the prepared fine particle aqueous dispersions was measured using a laser diffraction / scattering particle size distribution measuring device (trade name LA-960, manufactured by Horiba, Ltd.).

[0115] Each aqueous dispersion of fine particles was diluted appropriately with ion-exchanged water so that the mass ratio of fine particles in the sample was 0.2% by mass, so that the transmittance of the light incident on the sample was appropriate.

[0116] (Dispersion Stability Test) The dispersion stability of each prepared microparticle aqueous dispersion was tested.Specifically, 100ml of each prepared microparticle aqueous dispersion was left standing at 20 ℃, and the median diameter of the microparticle aqueous dispersion (i.e., the median diameter of the microparticles in the microparticle aqueous dispersion) was measured by the above-mentioned measuring method at appropriate times (specifically, 2 weeks, 4 weeks, 6 weeks, and 8 weeks after the preparation of the microparticle aqueous dispersion), and the change rate (%) from immediately after the preparation of the microparticle aqueous dispersion was calculated according to the following formula, and the dispersion stability was evaluated. Formula: Median diameter change rate (%) = [(Median diameter of aqueous microparticle dispersion after standing for each period) - (Median diameter of aqueous microparticle dispersion immediately after preparation)] / (Median diameter of aqueous microparticle dispersion immediately after preparation) x 100

[0117] The evaluation criteria are as follows: S: The rate of change in the median diameter of the aqueous microparticle dispersion after 8 weeks of standing is less than 50%. A: The rate of change in median diameter of the aqueous microparticle dispersion after 6 weeks of standing is less than 50%, but the rate of change in median diameter of the aqueous microparticle dispersion after 8 weeks of standing is 50% or more. B: The rate of change in the median diameter of the aqueous microparticle dispersion after 4 weeks of standing is less than 50%, but the rate of change in the median diameter of the aqueous microparticle dispersion after 6 weeks of standing is 50% or more. C: The rate of change in median diameter of the aqueous microparticle dispersion after being left standing for 2 weeks is 50% or more.

[0118] [Table 2]

[0119] [Table 3]

[0120] (Hydraulic composition) Next, a hydraulic composition (mortar) was prepared as follows: First, ordinary Portland cement (manufactured by Taiheiyo Cement Corporation, specific gravity = 3.16 g / cm 3 ) was placed in a mechanical mixer specified in JIS R5201. 3 ), and fine aggregate (Oigawa River watershed land sand, specific gravity = 2.58 g / cm 3 ) were added in the proportions shown in Table 4 and dry-mixed for 10 seconds. Next, the microparticle aqueous dispersion, a high-range water-reducing agent (Takemoto Yushi Co., Ltd.'s Chupol NV-80 (trade name)), and an antifoaming agent (Takemoto Yushi Co., Ltd.'s AFK-2 (trade name)) shown in Table 3 were added to the mixing water, and the microparticle aqueous dispersion, high-range water-reducing agent, and antifoaming agent were considered to be part of the mixing water and added together with the mixing water, followed by mixing for 180 seconds to obtain a hydraulic composition.

[0121] The amount of high-performance water-reducing agent added was in the range of 0.5 to 0.8% by mass relative to the cement, so that the prepared hydraulic composition would fall within the target mortar flow range (220±20 mm).An antifoaming agent was also added appropriately so that the air content of the mixed hydraulic composition would be 2% or less.

[0122] [Table 4]

[0123] The resulting hydraulic compositions were evaluated for mortar flow value and air content using the following evaluation methods. The measurement results are shown in Table 5.

[0124] (Mortar flow value) The hydraulic composition immediately after mixing was measured in accordance with JIS R5201 without dropping.

[0125] (air volume) The hydraulic composition immediately after mixing was measured using a mortar container in accordance with JIS A1116.

[0126] (Hydraulic composition cured product) Next, a hydraulic composition hardened body (hardened mortar) was produced using the obtained hydraulic composition, and the compressive strength (at an age of 16 hours, an age of 24 hours, and an age of 28 days) was measured.

[0127] Specifically, first, nine cylindrical tinplate mortar specimen molding forms (product name "Summit Mold", manufactured by Sumitomo Corporation, formwork bottom diameter: 50 mm, formwork height: 100 mm) were prepared, and each of these forms was filled with a hydraulic composition (mortar) using the two-layer filling method, followed by air curing (20°C) in a room at 20°C.

[0128] Two hours after the preparation of the hydraulic composition (mortar), the surface of the hydraulic composition (mortar) filled into the formwork was leveled and covered with polyethylene wrap to prevent moisture evaporation. Then, 16 hours after the preparation of the hydraulic composition (mortar), the hardened hydraulic composition (mortar) was removed from the formwork to obtain three specimens. The compressive strength of the three specimens obtained was then measured at 16 hours, and the average value was calculated.

[0129] Twenty-four hours after the preparation of the hydraulic composition (mortar), the remaining hardened hydraulic composition (mortar) was removed from the formwork to obtain six test specimens. The compressive strength of three of the test specimens was measured at 24 hours, and the average value was calculated. The remaining three test specimens were further cured in water at 20°C for an additional 27 days immediately after removal from the formwork, and then the compressive strength of the test specimens was measured at 28 days, and the average value was calculated.

[0130] The column for the compressive strength ratio (%) of the hardened mortar indicates the value calculated as a ratio with the "compressive strength of the hardened mortar" of Application Example 29 at each material age as the standard (100%).

[0131] The evaluation criteria for the compressive strength ratio of the hardened hydraulic composition (mortar) are shown below. (16-hour and 24-hour ages) S: Compressive strength ratio of the hydraulic composition hardened body is 126% or more A: The compressive strength ratio of the hydraulic composition hardened body is 116% or more and less than 126% B: Compressive strength ratio of the hydraulic composition hardened body is 103% or more and less than 116% C: Compressive strength ratio of the hydraulic composition hardened body is less than 103% (28 days old) S: Compressive strength ratio of the hydraulic composition hardened body is 113% or more A: The compressive strength ratio of the hydraulic composition hardened body is 109% or more and less than 113% B: Compressive strength ratio of the hydraulic composition hardened body is 103% or more and less than 109% C: Compressive strength ratio of the hydraulic composition hardened body is less than 103%

[0132] [Table 5]

[0133] (result) As shown in Table 3, it was confirmed that the dispersant for microparticles of this example can disperse microparticles in an aqueous dispersion medium and can obtain an aqueous dispersion in which the dispersed state is maintained over time (high dispersion stability over time).

[0134] Furthermore, as shown in Table 5, when an aqueous dispersion containing the dispersant of this Example is added to a hydraulic composition, as shown in Application Examples 1 to 23, it was confirmed that the compressive strength of the hydraulic composition hardened body (mortar hardened body) at an initial age (16 hours, 24 hours) and at a medium to long term age (28 days) can be improved compared to Application Examples 24 to 29 (those using the microparticle dispersants of Comparative Examples 1 to 5 and those not adding any microparticle dispersant). [Industrial Applicability]

[0135] The dispersant for fine particles of the present invention can be used as a dispersant for dispersing fine particles, and more specifically, can be used as an additive for a hydraulic composition for forming a hardened hydraulic composition such as a hardened product of concrete or mortar.

Claims

1. A dispersant for fine particles for dispersing fine particles, Contains the following organic phosphate ester (A): the fine particles are at least one fine particle selected from the group consisting of silica, aluminum oxide, calcium carbonate, titanium oxide, and calcium hydroxide; In P-nucleus NMR measurement of the organic phosphate ester (A) pretreated by alkaline overneutralization, when the total of the P-nucleus NMR integral ratios attributable to an organic phosphate ester P1 represented by the following general formula (1), an organic phosphate ester P2 represented by the following general formula (2), and an organic phosphate ester P3 represented by the following general formula (3) is taken as 100%, A dispersant for fine particles, characterized in that the P nucleus NMR integral ratio attributable to an organic phosphate ester P1 represented by the following general formula (1) is 50 to 99%: Organic phosphate ester (A): The organic phosphate ester P1 represented by the following general formula (1), the organic phosphate ester P2 represented by the following general formula (2), and the organic phosphate ester P3 represented by the following general formula (3) are included. 【Chemistry 1】 (In general formula (1), R １ is a styrenated phenyl group having 14 to 30 carbon atoms. １ O is an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of oxyalkylene groups are present, one type may be used alone or two or more types may be used). n1 is A １ is the average number of moles of O added, and is a number from 1 to 150. １ , M ２ are each independently a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine. 【Chemistry 2】 (In general formula (2), R ２ , R ３ are each independently a styrenated phenyl group having 14 to 30 carbon atoms. ２ O.A. ３ Each O is independently an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type may be used alone or two or more types may be used). ２ n3 is the average number of moles of O added, and is a number from 1 to 150. ３ is the average number of moles of O added, and is a number from 1 to 150. ３ is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine. 【Transformation 3】 (In general formula (3), R ４ , R ５ are each independently a styrenated phenyl group having 14 to 30 carbon atoms. ４ O.A. ５ O each independently represents an oxyalkylene group having 2 to 4 carbon atoms (however, when a plurality of such oxyalkylene groups are present, one type may be used alone or two or more types may be used). ４ n5 is the average number of moles of O added, and is a number from 1 to 150. ５ is the average number of moles of O added, and is a number from 1 to 150. ４ is a hydrogen atom, an alkali metal, an alkaline earth metal (1 / 2), ammonium, or an organic amine. r is an integer of 2 or 3.

2. In the general formulas (1) to (3), A １ O-A ５ 2. The dispersant for fine particles according to claim 1, wherein each O is independently composed of 50 mol % or more of polyoxyethylene units.

3. 3. The dispersant for fine particles according to claim 1, wherein in the general formulas (1) to (3), n1 to n5 each independently represent an integer of 1 to 75.

4. The dispersant for microparticles according to any one of claims 1 to 3, which is added to a dispersion containing the microparticles, and which has a median diameter of 10 to 1,000 nm as measured by a laser diffraction / scattering particle size distribution measuring device in the dispersion.

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