JP6553885B2 - Surface-coated inorganic particles and method for producing the same, surface coating agent, and method for producing hydraulic composition - Google Patents

Description

The present invention relates to surface-coated inorganic particles and a method for producing the same, a surface coating agent, and a method for producing a hydraulic composition.

In addition to the narrowly defined hydraulic particles in which the hydration reaction occurs in the presence of water, the hydraulic particles do not hydrate with water alone, but the hydration reaction in the presence of a small amount of a substance called a stimulant. There are latent hydraulic particles that cause

In general, hydraulic particles are used in combination with a dispersant, water, and fine aggregates, coarse aggregates, and the like, if necessary, to obtain hydraulic compositions such as cement paste, mortar, and concrete. For example, to produce fresh (raw) concrete, in a mixer, in a narrow sense, hydraulic particles such as cement, dispersant, water, fine aggregate and coarse aggregate, and if necessary silica fume, blast furnace A fine powder such as slag, fly ash or the like is added and mixed for a certain period of time, and the dispersing agent disperses the paste and knead it until the fluidity becomes constant, that is, the fluidity is stabilized. The dispersant is usually added to the hydraulic particles, usually mixed beforehand with water. After adding water (containing a dispersant) to the hydraulic particles in this way, the time until the fluidity stabilizes is referred to as the kneading time or the time until the kneading ends, but until the fluidity stabilizes. Usually takes a certain amount of time.

As a hydraulic composition containing a dispersing agent, for example, Patent Document 1 discloses a cement admixture containing a calcium aluminate compound exhibiting a predetermined physical property value and a water reducing agent. In this document, it is described that a water reducing agent can be used in the form of liquid or powder in which the water reducing agent component is dissolved in water.

JP 2010-1000046 A JP 2011-068134 A Japanese Patent Application Publication No. 2008-503432

As described above, it is usual for the kneading time to take a fixed time. In particular, the time until the flowability is stabilized, that is, the kneading time tends to be longer, as the weight ratio of water / hydraulic particles is lower in ultra-high-strength concrete. If this can be improved and the kneading time can be shortened, for example, the production time per batch in a concrete manufacturing plant can be shortened, which can greatly contribute to the improvement of productivity. However, at present, no technology that can sufficiently solve such problems has been found. In the technique described in Patent Document 1, even if the dispersant is used in powder form, it does not contribute to shortening the kneading time.

The present invention has been made in view of the above situation, and provides a surface-coated inorganic particle capable of significantly reducing the kneading time and capable of giving a hydraulic composition excellent in fluidity with high productivity and a method for producing the same. Intended to be provided. Another object of the present invention is to provide a surface coating agent particularly suitable for obtaining such surface-coated inorganic particles, and a method of producing a hydraulic composition using the surface-coated inorganic particles.

As a result of various studies on the production technique of the hydraulic composition, the present inventor has produced a hydraulic composition in which part or all of the surface of the hydraulic inorganic particle is coated with an organic dispersant, and the particle When surface-coated inorganic particles having a carbon content ratio (carbon concentration) in the surface or in the vicinity of the surface are in a predetermined range, a kneading time until fluidity is stabilized can be remarkably shortened, and a hydraulic composition exhibiting high fluidity can be obtained. I found what I could give. It was also found that the same phenomenon occurs with surface-coated inorganic particles using pozzolanic active inorganic particles. Even when the mass ratio of water / hydraulic particles is low, if such surface-coated inorganic particles are used, a hydraulic composition exhibiting high fluidity can be easily obtained in a short time, so that productivity is improved. It will be very excellent. In addition, the surface coating agent containing at least one selected from the group consisting of a sulfonic acid group-containing compound and / or a phosphoric acid group-containing compound has an adsorptivity to hydraulic inorganic particles and pozzolanic active inorganic particles, and after adsorption It has also been found that the particle dispersibility (that is, after surface coating) is good, so that it is suitable for use as a surface coating agent for these inorganic particles. Then, the inventors have arrived at the present invention by conceiving that the above problems can be solved brilliantly.

Here, although the cement particle (for example, particle coating 22 grade etc. in a figure) covered with the concrete fluidization agent 13 which is an additive is described in patent document 2 mentioned above, the concrete fluidization agent 13 is Since the fluidizing agent 13 can not sufficiently cover the cement surface because it is supplied by spraying together with a small amount of water, and because the amount of water to be added is small, the cement particles can It can not be dispersed. Patent Document 3 describes that an aqueous composition containing polymer A having a predetermined structure is used as a cement grinding aid. Since this cement grinding aid is added to the clinker (cement raw material) as an aqueous composition essentially containing a small amount of water, in this case too, the surface cannot be sufficiently coated during cement grinding, and cement particles are produced during grinding. Cannot be sufficiently dispersed. In the techniques of Patent Documents 2 and 3, the dispersibility of the fluidizing agent is not exhibited because water is used as the solvent and the particle surface is not sufficiently covered with the dispersant. Therefore, according to these techniques of Patent Documents 2 and 3, it is not possible to improve the fluidity and further shorten the kneading time.

That is, according to the present invention, part or all of the surface of at least one inorganic particle selected from the group consisting of hydraulic inorganic particles and pozzolanic active inorganic particles is coated with an organic dispersant, and silicon of the particle surface ( When the relative surface concentration of carbon (C) to Si) and calcium (Ca) is measured by XPS, the relative surface concentration of carbon (C) is 0.35 to 50 and the depth at 1 to 2 nm from the particle surface Relative surface concentration of the average carbon (C) is 0.17 to 50, and the organic dispersant is at least one selected from the group consisting of a sulfonic acid group-containing compound and / or a phosphoric acid group-containing compound It is surface-coated inorganic particle which is 1 type.
The present invention is also hydraulic particles containing the above surface-coated inorganic particles.
The present invention is also a method for producing a hydraulic composition using the surface-coated inorganic particles.

The present invention is further a method of producing the surface-coated inorganic particles, wherein the method comprises organically dispersing at least one inorganic particle selected from the group consisting of hydraulic inorganic particles and pozzolanic active inorganic particles. The organic dispersant is selected from the group consisting of a sulfonic acid group-containing compound and / or a phosphate group-containing compound. It is also a method of producing at least one surface-coated inorganic particle.
The present invention is also a surface coating agent for inorganic particles used to obtain the surface-coated inorganic particles, wherein the inorganic particles are at least one selected from the group consisting of hydraulic inorganic particles and pozzolanic active inorganic particles. The surface coating agent is also a surface coating agent containing at least one selected from the group consisting of a sulfonic acid group-containing compound and / or a phosphoric acid group-containing compound.
The present invention is described in detail below. In addition, the form which combined each preferable form of this invention described below 2 or 3 or more is also a preferable form of this invention.

In the present specification, “kneading time” means the time until the flowability is stabilized after water is added to the hydraulic inorganic particles and / or the pozzolanic active inorganic particles. “Stability of the flow” means that the softness of the paste containing the hydraulic inorganic particles and / or pozzolanic active inorganic particles and water becomes uniform, and whether it is uniform or not is visually confirmed It can be judged. The kneading time is also referred to as time until kneading.

[Surface-coated inorganic particles]
The surface-coated inorganic particles of the present invention have a form in which part or all of the surface of predetermined inorganic particles is coated with an organic dispersant.
The surface-coated inorganic particles are preferably in the range of, for example, 0.01 to 100 μm as an average particle size. By being in such a range, the kneading time can be further shortened, and it becomes possible to give a uniform fluidity to the obtained hydraulic composition. More preferably, it is 0.05-75 micrometers, More preferably, it is the range of 0.1-50 micrometers.

(Particle size measurement method)
In the present specification, the particle size of the particles can be measured using a commercially available particle size distribution measuring device. As an example, after ultrasonically dispersing a sample with ethanol using a laser diffraction / scattering type particle size distribution measuring apparatus LA-910 manufactured by HORIBA, it can be measured under the condition of relative refractive index 1.10.

The inorganic particles for obtaining the surface-coated inorganic particles are at least one selected from the group consisting of hydraulic inorganic particles and pozzolanic active inorganic particles. These inorganic particles preferably have an average particle diameter in the range of 0.001 to 100 μm, for example. Preferably it is 0.01-100 micrometers, More preferably, it is the range of 0.05-75 micrometers.
It is preferable that the hydraulic inorganic particles and the pozzolanic active inorganic particles are not yet hydrated (cured), that is, unhydrated.

In the above-mentioned hydraulic inorganic particles, "hydraulic" means that hydration reaction occurs in the presence of water, and in a narrow sense "hydraulic" such as curing as a solid, it does not hydrate with water alone, It also means “latent hydraulic” in which a hydration reaction takes place in the presence of a small amount of substance called an irritant and hardens as a solid.

Examples of the hydraulic inorganic particles include narrowly defined hydraulic inorganic particles such as cement and alumina; latent hydraulic inorganic particles such as slag; and the like, and are composed of one or more of these. It is also good. Among them, cement and blast furnace slag are preferable, which makes it possible to more fully exhibit the function and effect of the present invention of shortening the kneading time.

Specific examples of the cement include Portland cement (ordinary, early strength, ultra-early strength, low heat, moderate heat, sulfate resistant and low alkali type), various mixed cements (blast furnace cement, silica cement, fly ash cement). White cement, alumina cement, super rapid curing cement (1 clinker quick curing cement, 2 clinker quick curing cement, magnesium phosphate cement), grout cement, oil well cement, low heat generation cement (low heat generation blast furnace cement, fly ash mixed Low exothermic type blast furnace cement, cement with high belite content), ultra-high strength cement, cement-based solidified material, eco-cement (cement produced from one or more of municipal waste incineration ash and sewage sludge incineration ash) .

The pozzolanic active inorganic particles mean inorganic particles having pozzolanic activity, and examples thereof include silica fume, fly ash, cinder ash, husk ash, volcanic ash, etc., and one or more of these may be used. it can. Among them, silica fume and fly ash are preferable, which makes it possible to more fully exhibit the function and effect of the present invention of shortening the kneading time.

The inorganic particles are particularly preferably at least one selected from the group consisting of cement, silica fume, fly ash and slag. As a result, the effect of the present invention of shortening the kneading time can be more fully exhibited. Thus, the form in which the inorganic particles are at least one selected from the group consisting of cement, silica fume, fly ash and slag is one of the preferred forms of the present invention.

In the present invention, the surface-coated inorganic particles in which part or all of the cement surface is coated with an organic dispersant, and part or all of the surface of silica fume, fly ash and / or slag are coated with an organic dispersant. It is particularly preferred to use the surface-coated inorganic particles together. Normally, inorganic particles such as silica fume and fly ash have a small particle size, so when the inorganic particles are used as they are (that is, without being subjected to a coating treatment) for producing a hydraulic composition, the kneading time becomes long. Productivity is not enough. However, if particles obtained by mixing a part or all of the surface of these inorganic particles with an organic dispersant and then mixing such surface-coated inorganic particles are used, when mixed with water, kneading The silica fume cement, fly ash cement, and blast furnace slag cement having a high fluidity can be provided by significantly shortening the time.

The form in which a part or all of the surface of the inorganic particles is coated with the organic dispersant means that the organic dispersant is adsorbed or adhered to the surface of the inorganic particles. Since the organic dispersant has a carbon atom, if the organic dispersant is present in the inorganic particles and the carbon content (carbon concentration) of the surface (or near the surface) is improved, the organic particle is organic on the surface of the inorganic particles It is inferred that the system dispersant is adsorbed or attached, that is, part or all of the surface of the inorganic particles is coated with the organic dispersant.
The adsorption or adhesion of the organic dispersant on the particle surface can be confirmed, for example, by measuring the carbon content (carbon concentration) of the particle surface using X-ray photoelectron spectroscopy or the like. it can.

X-ray photoelectron spectroscopy is an analysis method in which a solid surface is excited with soft X-rays under high vacuum and photoelectrons emitted from the surface are measured (hereinafter referred to as XPS analysis method or XPS). This analysis provides information on the oxidation state and concentration of elements present in the vicinity of a few nanometers near the surface, and the relative concentration of C (carbon) relative to Si (silicon) and Ca (calcium) on the surface can be identified. Be

(XPS analysis method)
In the present invention, the relative surface concentration of C with respect to Si and Ca in the surface-coated inorganic particles is measured. The relative surface concentration of C to Si and Ca are counts per vertical axis per second, the horizontal axis XPS chart showing the binding energy, the value of the peak area was divided by the sensitivity coefficient of the C _1s of C _1s, Si Table the peak area of _2p and divided by the sensitivity coefficient of the Si _2p, in total of the value of the peak area was divided by the sensitivity coefficient of the Ca _2p of Ca _2p, a value obtained by dividing, by the following equation (1) Is done.

The peak areas of C _1s , Si _2p and Ca _2p can be measured and calculated by the following procedure.
Measurement apparatus: ULVAC-PKI company, PHI Quantera SXM is used, an X-ray source is AlK alpha, a beam diameter is 100 μm, and a beam output is 25 W-15 kV.
Sample preparation method: After filling the particle powder which is a measurement sample in φ3 washer made by SUS Co., fix it with finger pressure using a spatula. Set it on the sample table with a jig made of SUS. Do not use any carbon type jig such as carbon tape.
Depth direction analysis method: Ar ⁺ ions (2 kV-25 mA) are used to perform edging at a rate of 8 nm / min in terms of SiO ₂ to perform depth direction analysis.
In the measurement of Si _2p , Ca _2p , and C _1s , the path energy is set to 280 eV and the energy step is set to 0.5 eV.
The peak area of Si _2p is calculated by accumulating 14 peaks around 100 eV and removing the background by the Shirley method.
The peak area of Ca _2p is calculated by integrating the peaks around 345 to 350 eV 14 times and then removing the background by the Shirley method.
The peak area of C _1s is calculated by accumulating 14 peaks around 285 eV and removing the background by the Shirley method.
The sensitivity coefficient is a value unique to the measuring device, and the sensitivity coefficients of Si _2p , Ca _2p and C _1s of the device are 119.676, 597.269 and 87.799, respectively. Therefore, the "relative surface concentration" referred to in the present specification is a value determined using a measuring apparatus "PHI Quantera SXM" manufactured by ULVAC-PKI.

When the relative surface concentration of C to Si and Ca on the surface of the particle is measured by XPS, the relative surface concentration of C to Si and Ca on the particle surface (depth 0 nm) is 0.35 And the relative surface concentration of C having an average depth of 1 to 2 nm from the particle surface is 0.17 to 50. Thereby, kneading | mixing time can be shortened more and it becomes possible to give the hydraulic composition excellent in fluidity | liquidity with sufficient productivity. The lower limit value of the relative surface concentration of C relative to Si and Ca on the particle surface (depth 0 nm) is more preferably 0.4 or more, still more preferably 0.5 or more, and particularly preferably 0.8 or more. The upper limit is more preferably 30 or less, still more preferably 10 or less, particularly preferably 5 or less, and most preferably 3 or less. The lower limit value of the relative surface concentration of the average C of the depth at 1 to 2 nm from the particle surface is more preferably 0.18 or more, still more preferably 0.20 or more, particularly preferably 0.25 or more, more preferably 0 .3 or more. The upper limit is more preferably 30 or less, still more preferably 10 or less, particularly preferably 5.0 or less, and most preferably 3.0 or less.

The above “relative surface concentration of C at an average depth of 1 to 2 nm from the particle surface” means the relative surface concentration of C at a depth of 1 nm from the surface and the relative surface of C at a depth of 2 nm from the surface It means the average value with the concentration. The carbon content ratio on the particle surface (depth 0 nm) may have an effect due to surface contamination, but the effect is reduced at a depth of 1 nm or more from the surface, so an organic dispersant is present on the particle surface. It is possible to more accurately confirm that it is adsorbed or adhered.

In addition, as a method for confirming that the organic dispersant is present in the inorganic particles, a solvent such as water or alcohol was added to the particles partially or entirely coated with the organic dispersant and stirred for a predetermined time. Thereafter, the supernatant can be separated by centrifugation or the like, and the supernatant can be dried and analyzed by NMR or the like.

In the present invention, at least one selected from the group consisting of a sulfonic acid group-containing compound and a phosphoric acid group-containing compound is used as the organic dispersant. These have dispersion performance, and also have good adsorptivity to the surface of hydraulic inorganic particles and pozzolanic active inorganic particles, so that the effects of the present invention can be exhibited.
In addition, the compound which has both a sulfonic acid group and a phosphoric acid group in 1 molecule is also contained in the organic type dispersing agent of this invention.

In the present specification, the sulfonic acid group includes a sulfonic acid group, and the phosphoric acid group includes a phosphate group. Although the salt which comprises these bases is not specifically limited, For example, an alkali metal salt, alkaline-earth metal salt, ammonium salt, organic ammonium salt etc. are mentioned.

-Sulphonic acid group-containing compound-
The sulfonic acid group-containing compound is a compound having a sulfonic acid group in the molecule, and one or two or more compounds generally used for hydraulic inorganic particles as a sulfonic acid-based dispersant can be used. Among these, a compound having an aromatic group in the molecule is preferable.
Specifically, for example, polyalkylaryl sulfonates such as naphthalene sulfonic acid formaldehyde condensate, methyl naphthalene sulfonic acid formaldehyde condensate, anthracene sulfonic acid formaldehyde condensate; melamine formalin resin sulfonic acid such as melamine sulfonic acid formaldehyde condensate Salts; aromatic amino sulfonates such as aminoaryl sulfonic acid-phenol-formaldehyde condensates; lignin sulfonates such as lignin sulfonates and modified lignin sulfonates; polystyrene sulfonates;

The sulfonic acid group-containing compound is more preferably a condensate (which may be a salt) having a naphthalene structure. Among them, a condensate of a naphthalenesulfonic acid-based compound represented by the following general formula (1) with an aldehyde compound is particularly preferable in view of dispersibility, fluidity retention, strength development and the like. In addition, you may use the mixture of two or more condensates from which a condensation degree differs.

In general formula (1), R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. M ¹ represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an ammonium group, an alkyl ammonium group or a substituted alkyl ammonium group.

Examples of the naphthalene sulfonic acid compound represented by the general formula (1) include naphthalene, methyl naphthalene, isopropyl naphthalene, and the like, and one or more can be used.

The above-mentioned aldehyde compound is not particularly limited as long as it is a compound having an aldehyde group (-C (= O) H), and one or more kinds can be used. For example, formaldehyde, glyoxylic acid, benzaldehyde or a derivative thereof can be used. Examples of benzaldehyde derivatives include benzaldehyde salts, as well as acid derivatives such as benzaldehyde carboxylic acid, benzaldehyde sulfonic acid, benzaldehyde disulfonic acid and benzaldehyde phosphonic acid, and salts thereof such as alkali metal salts, alkaline earth metal salts and ammonium salts And organic ammonium salts. Of these, formaldehyde is preferable.

The salt of the condensate is not particularly limited, and examples thereof include alkali metal salts, alkaline earth metal salts, ammonium salts, and organic ammonium salts. Among these, alkali metal salts are preferable, and sodium salts are preferable among them.

In the above condensation, in addition to the naphthalenesulfonic acid compound and the aldehyde compound, a sulfonated bisphenol compound may be added. That is, the above-mentioned condensate may contain a condensate (which may be a salt) of a sulfonated compound of a bisphenol compound and an aldehyde compound.

The bisphenol compound may be a compound having two hydroxyphenyl groups in one molecule of the compound. For example, a compound having a structure in which two hydroxyphenyl groups are linked via any divalent group is suitable. The divalent group is not particularly limited. For example, -CH _2- , -C (Me) _2- , -C (Me) (Et)-, -C (Ph) _2- , -O-, -S ( ═O) ₂ — and the like (Me represents a methyl group, Et represents an ethyl group, and Ph represents a phenyl group). The hydroxyphenyl group may have a substituent such as an alkyl group or an aryl group.

Specific examples of the bisphenol compound include bis (hydroxyphenyl) propane, bis (hydroxyphenyl) butane, dihydroxydiphenylmethane, dihydroxydiphenyl ether, and dihydroxydiphenylsulfone.
The sulfonation of the bisphenol compound is not particularly limited, and may be carried out by the usual method in the presence of a usual sulfonating agent (eg, sulfuric acid, chlorsulfonic acid, sulfur trioxide and the like).

The condensation reaction is not particularly limited, and ordinary means may be used.
In the condensation reaction of the naphthalene sulfonic acid compound and the aldehyde compound, it is preferable that the ratio thereof (naphthalene sulfonic acid compound / aldehyde compound; mol%) is 10 to 90/90 to 10. More preferably, it is 10 to 50/50 to 90. Furthermore, when a condensation reaction is performed by adding a sulfonated compound of a bisphenol compound, 50 to 99% by mole of the naphthalenesulfonic acid compound is contained in 100 mol% of the total of the naphthalenesulfonic acid based compound and the sulfonated compound of the bisphenol compound. It is preferable to do. More preferably, it is 30 to 90 mol%.

The weight average molecular weight (Mw) of the sulfonic acid group-containing compound is determined based on the binding property (adsorbability) to the hydraulic inorganic particles and pozzolanic active inorganic particles, the aggregating action of these inorganic particles, and the flow of the obtained hydraulic composition. In view of retention and the like, it is preferable that the weight average molecular weight (Mw) is 3000 to 500,000. More preferably, it is 5000-300,000, More preferably, it is 7000-200,000, Most preferably, it is 8000-100,000.
The weight average molecular weight of the sulfonic acid group-containing compound can be measured, for example, by gel permeation chromatography (also referred to as GPC) using polystyrene sulfonic acid as a standard substance under the following measurement condition (1).

(GPC measurement conditions (1))
Equipment: Waters, Waters Alliance (2695)
Analysis software: Waters, Empor professional + GPC option column: Tosoh, TSK guard column SWXL + TSKgel G4000SWXL + G2000SWXL
Detector: Multiwavelength visible ultraviolet (PDA) detector (Waters 2996)
Eluent: 30 mM CH3COONa / CH3CN = 6/4
Standard material for creating calibration curve: polystyrene sulfonic acid [peak top molecular weight (Mp) 976000, 356000, 77900, 15650, 4600] manufactured by Soka Scientific Co., Ltd.
Calibration curve: Based on the Mp value of the above-mentioned polystyrene sulfonic acid and the elution time, the flow rate is 0.7 mL / min.
Column temperature: 40 ° C
Measurement time: 45 minutes Sample solution injection amount: 100 μL (eluent preparation solution with sample concentration of 0.5 mass%)

-Phosphate group-containing compound-
The phosphate group-containing compound is a compound having a phosphate group in the molecule, and one or two or more compounds generally used for hydraulic inorganic particles as a phosphate dispersant can be used. Among these, a phosphoric acid polymer and a phosphoric acid condensate containing polyalkylene glycol are preferable from the viewpoint of better dispersion performance.

The weight average molecular weight (Mw) of the phosphoric acid group-containing compound containing the polyalkylene glycol is determined based on the binding property (adsorbability) to the hydraulic inorganic particles and the pozzolanic active inorganic particles, the aggregating action of these inorganic particles, and the water obtained. Considering the fluidity retention of the hard composition, the weight average molecular weight (Mw) is preferably 3000 to 500,000. More preferably, it is 5000-300,000, More preferably, it is 7000-200,000, Most preferably, it is 8000-100,000.
The weight average molecular weight can be measured, for example, by GPC using polyethylene glycol as a standard substance under the following measurement condition (2).

(GPC measurement conditions (2))
Equipment: Waters, Waters Alliance (2695)
Analysis software: Waters, Empower Professional + GPC Optional Column: Tosoh, TSK guard column SWXL + TSKgel G4000SWXL + G3000SWXL + G2000SWXL
Detector: differential refractometer (RI) detector (Waters 2414, manufactured by Waters)
Eluent: Dissolve 115.6 g of sodium acetate trihydrate in a mixed solvent of 10999 g of water and 6001 g of acetonitrile, and adjust the pH to 6.0 with acetic acid. Standard substance for preparing a solution calibration curve: Polyethylene glycol [Peak top molecular weight (Mp 300000, 200000, 107000, 50000, 27700, 11840, 6450, 1470]
Calibration curve: Created by cubic equation based on Mp value and elution time of polyethylene glycol Flow rate: 1.0 mL / min
Column temperature: 40 ° C
Measurement time: 45 minutes Sample solution injection amount: 100 μL (eluent preparation solution with sample concentration of 0.5 mass%)

(I) Phosphoric Acid-Based Polymer The phosphoric acid-based polymer may be a polymer containing a phosphoric acid group, for example, a (poly) alkylene glycol-based monomer represented by the following general formula (2) The polymer is preferably a polymer obtained by polymerizing a monomer component containing a phosphoric acid monomer represented by the following general formula (3).

In the general formula (2), R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom, a methyl group or -COO (A ¹ O) _n -R ⁵ . A ¹ O is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. n represents the average addition mole number of the oxyalkylene group represented by A ¹ O, and is the same or different and is a number of 1 to 300. R ⁵ is the same or different and represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.

In general formula (3), R ⁶ represents a hydrogen atom or a methyl group. A ² O (also expressed as “OA ² ”) is the same or different and represents an oxyalkylene group having 2 to 18 carbon atoms. m represents the average addition mole number of the oxyalkylene group represented by A ² O, and is a number of 1 to 300. M ² and M ³ are the same or different and each represents a hydrogen atom, an alkali metal atom, an alkaline earth metal atom, an ammonium group, an alkyl ammonium group or a substituted alkyl ammonium group. Either M ² or M ³ may represent CH ₂ ═C (R ⁶ ) —CO— (OA ² ) _m —.

In the above general formula (2), R ² , R ³ and R ⁴ are the same or different and each represents a hydrogen atom, a methyl group or -COO (A ¹ O) _n -R ⁵ , but at least R ⁴ is hydrogen Preferably it represents an atom. Further, as R ² and R ³ , it is preferable that R ² is a hydrogen atom and R ³ is a methyl group.

A ¹ O represents an oxyalkylene group having 2 to 18 carbon atoms (the oxyalkylene group also includes an oxystyrene group), and this carbon number is preferably 2 to 8, more preferably 2 to 4, and even more. Preferably it is 2, ie an oxyethylene group. In particular, the oxyethylene group is preferably 70 mol%, more preferably 80 mol% or more, still more preferably 90 mol% or more, particularly preferably 100 mol%, that is, 100 mol% of the total number of oxyalkylene groups. (A ¹ O) The (poly) alkylene glycol chain represented by _n is a (poly) ethylene glycol chain.
When two or more oxyalkylene groups are present, the addition form may be any addition form such as random addition, block addition, alternate addition, and the like.

n represents an average addition mole number of the oxyalkylene group represented by ^{A 1} O, is a number from 1 to 300, preferably 3 to 200, more preferably 4 to 120. By being in such a range, the polymerization reactivity of the (poly) alkylene glycol monomer and the hydrophilicity of the resulting polymer become more sufficient, so the effects of the present invention are more fully exhibited. It becomes possible.

R ⁵ represents a hydrogen atom or a hydrocarbon group having 1 to 18 carbon atoms.
When R ⁵ represents a hydrocarbon group, the number of carbon atoms (number of carbon atoms) is preferably 1 to 12, more preferably 1 to 4, particularly preferably 1 from the viewpoint of further improving the hydrophilicity of the obtained polymer. It is ~ 2. As the hydrocarbon group, for example, an alkyl group (straight chain, branched chain or cyclic), a phenyl group, an alkyl-substituted phenyl group, an alkenyl group, an alkynyl group, an aryl group, and the like are preferable. Chain or cyclic) is preferable, and a methyl group is more preferable.

As the (poly) alkylene glycol monomer represented by the general formula (2), for example, an unsaturated carboxylic acid (poly) alkylene glycol ester compound is preferable. Particularly preferred are (meth) acrylates and (hydroxy) polyalkylene glycol mono (meth) acrylates.

As the above (alkoxy) (poly) alkylene glycol mono (meth) acrylate, for example, alkoxy (poly) alkylene glycols obtained by adding 2 to 300 moles of an alkylene oxide group having 2 to 18 carbon atoms to alcohols are preferable. More preferably, it is an esterified product of alkoxy (poly) alkylene glycols mainly composed of ethylene oxide and (meth) acrylic acid.

Examples of the alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 2-pentanol, 3-pentanol, 1-hexanol, 2-hexanol C1-C30 aliphatic alcohols such as 3-hexanol, octanol, 2-ethyl-1-hexanol, nonyl alcohol, lauryl alcohol, cetyl alcohol and stearyl alcohol; C3-C30 fats such as cyclohexanol Cyclic alcohols; unsaturated alcohols having 3 to 30 carbon atoms such as (meth) allyl alcohol, 3-buten-1-ol, 3-methyl-3-buten-1-ol, etc .; and the like.

Specifically as the above-mentioned esterified compound, (alkoxy) (poly) ethylene glycol (poly) (alkylene glycol having 2 to 4 carbon atoms) (meth) acrylic acid esters shown below, (hydroxy) (poly) ethylene glycol (poly) Poly) (C2-C4 alkylene glycol) (meth) acrylic acid esters and the like are suitable.

Hydroxy polyethylene glycol mono (meth) acrylate, methoxy polyethylene glycol mono (meth) acrylate, hydroxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, methoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, Hydroxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, methoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, hydroxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} mono (meta ) Acrylate, methoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol } Mono (meth) acrylate, ethoxy polyethylene glycol mono (meth) acrylate, ethoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, ethoxy {polyethylene glycol (poly) butylene glycol} mono (meth) acrylate, ethoxy { Polyethylene glycol (poly) propylene glycol (poly) butylene glycol} mono (meth) acrylate, propoxypolyethyleneglycol mono (meth) acrylate, propoxy {polyethyleneglycol (poly) propyleneglycol} mono (meth) acrylate, propoxy {polyethyleneglycol (poly ) Butylene glycol} mono (meth) acrylate, propoxy {polyethylene glycol (poly) propylene glycol (Poly) butylene glycol} mono (meth) acrylate, butoxypolyethylene glycol mono (meth) acrylate, butoxy {polyethylene glycol (poly) propylene glycol} mono (meth) acrylate, butoxy {polyethylene glycol (poly) butylene glycol} mono (Meth) acrylate, butoxy {polyethylene glycol (poly) propylene glycol (poly) butylene glycol} mono (meth) acrylate, and the like.

In the above general formula (3), A ² O represents an oxyalkylene group having 2 to 18 carbon atoms, preferably 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms, and still more preferably 2 to 4 carbon atoms. Particularly preferred is 2, ie an oxyethylene group. In particular, the oxyethylene group is preferably 70 mol%, more preferably 80 mol% or more, still more preferably 90 mol% or more, particularly preferably 100 mol%, that is, 100 mol% of the total number of oxyalkylene groups. (A ² O) The (poly) alkylene glycol chain represented by _n is a (poly) ethylene glycol chain.
When two or more oxyalkylene groups are present, the addition form may be any addition form such as random addition, block addition, alternate addition, and the like.

m represents the average addition mole number of the oxyalkylene group represented by A ² O, and is a number of 1 to 300, preferably 1 to 30, more preferably 1 to 20, still more preferably 1 to 10, Especially preferably, it is 1-5.

The phosphoric acid monomer represented by the above general formula (3) is, for example, mono (2-hydroxyethyl) (meth) acrylic acid phosphate, di-{(2-hydroxyethyl) (meth) phosphoric acid Acrylic acid} ester, (poly) alkylene glial mono (meth) acrylate acid phosphate, and the like are preferable. Among them, mono (2-hydroxyethyl) methacrylic acid phosphate ester and di-{(2-hydroxyethyl) methacrylic acid} ester phosphate are particularly preferable from the viewpoint of easiness of production and quality stability.

The monomer component is also a monomer copolymerizable with a (poly) alkylene glycol monomer and / or a phosphate monomer, and other monomers (also referred to as other monomers). 1 type or 2 types or more may be included. When the other monomer is contained, the content is preferably 30 mol% or less, more preferably 20 mol% or less, still more preferably 10 mol% or less, of the total 100 mol% of the monomer components. Is 0 mol%.

Although it does not specifically limit as said other monomer, For example, the unsaturated alcohol polyalkylene glycol adduct illustrated by international publication 2014/010572 [0023]-[0027]; In addition to the unsaturated carboxylic acid monomers exemplified in [0033] and [0036], various diesters exemplified in the publications [0041] to [0042]; diamides; half amides; (poly) Alkylene glycol di (meth) acrylates; multifunctional (meth) acrylates; (poly) alkylene glycol dimaleates; unsaturated sulfonic acids and salts thereof; amides such as methyl (meth) acrylamide; vinyl aromatics; alkanes Diol mono (meth) acrylates; dienes; unsaturated amides; unsaturated cyanides; Le acids; unsaturated amines; divinyl aromatics; cyanurates; siloxane derivative; and the like.

In the polymerization reaction of the (poly) alkylene glycol monomer and the phosphoric acid monomer, the ratio ((poly) alkylene glycol monomer / phosphoric acid monomer; mol%) is 5 It is preferable to set it to -95 / 95-5. More preferably, it is 10-90 / 90-10. Here, it is calculated that the phosphoric acid monomer is an acid type compound.

The polymerization method of the monomer component containing the said (poly) alkylene glycol type monomer and a phosphoric acid type monomer is not specifically limited, A normal polymerization means may be used. For example, a method described in JP 2006-52381 A can be mentioned.

(Ii) Phosphoric Acid-Based Condensate The phosphoric acid-based condensate is, for example, preferably a condensate of a phosphoric acid ester and an aldehyde compound. The phosphoric acid ester is not particularly limited as long as it is an esterified product of phosphoric acid (which may be a salt) and a hydroxyl group-containing compound, and one or more kinds can be used. In addition, any of phosphoric acid monoester, phosphoric acid diester, and phosphoric acid triester may be sufficient.

The phosphoric acid may be a compound having a phosphoric acid group, and examples thereof include compounds having a structure in which —PO ₃ H ₂ or —OPO ₃ H ₂ or the like is bonded to a hydrocarbon skeleton in addition to phosphoric acid. . The hydrocarbon skeleton here is not particularly limited, and an alkyl chain (for example, a linear, branched or cyclic alkyl group having 1 to 30 carbon atoms), an aromatic ring (for example, an aromatic ring having 6 to 10 carbon atoms), a complex And a ring (for example, a 5- to 10-membered heterocyclic ring). The heterocyclic ring preferably has 1 to 5 heteroatoms (preferably O, N, S and / or P), more preferably 1 to 3 and still more preferably 1 to 2. Specifically, for example, phenylphosphonic acid and the like can be mentioned.
In addition, when phosphates are salts, an alkali metal salt, alkaline-earth metal salt, ammonium salt, organic ammonium salt etc. are mentioned, for example.

The above-mentioned hydroxyl group-containing compound preferably has an aromatic ring. For example, phenol, phenoxy alcohol, phenoxy (poly) alkylene glycol, naphthol, naphthoxy alcohol, naphthoxy (poly) alkylene glycol and the like can be mentioned. The alcohol constituting phenoxy alcohol or naphthoxy alcohol is preferably, for example, an alcohol having 1 to 10 carbon atoms, and the (poly) alkylene glycol chain constituting phenoxy (poly) alkylene glycol or naphthoxy (poly) alkylene glycol is: (Poly) ethylene glycol is preferable, and the average chain length of the (poly) alkylene glycol chain is preferably 1 to 300.
As a specific example of the esterified substance of the said phosphoric acid and a hydroxyl-containing compound, the phenoxy ethanol phosphate etc. which esterified phenoxy ethanol by phosphoric acid etc. are mentioned, for example.

The above-mentioned aldehyde compound is not particularly limited as long as it is a compound having an aldehyde group (-C (= O) H), and one or more kinds can be used. For example, formaldehyde, glyoxylic acid, benzaldehyde or a derivative thereof can be used. Examples of benzaldehyde derivatives include benzaldehyde salts, as well as acid derivatives such as benzaldehyde carboxylic acid, benzaldehyde sulfonic acid, benzaldehyde disulfonic acid and benzaldehyde phosphonic acid, and salts thereof such as alkali metal salts, alkaline earth metal salts and ammonium salts And organic ammonium salts.

In the above condensation, in addition to the phosphoric acid ester and the aldehyde compound, one or more aromatic compounds and / or heterocyclic compounds having a (poly) alkylene glycol chain may be added. Thereby, dispersibility and dispersion retention can be more imparted or improved.
The aromatic compound and / or heterocyclic compound having a (poly) alkylene glycol chain has, for example, a structure in which a (poly) alkylene glycol chain is bonded to a compound containing an aromatic ring and / or a compound containing a heterocyclic ring. Is preferred.
The compound containing an aromatic ring preferably contains an aromatic ring having 6 to 10 carbon atoms.
The compound containing a heterocyclic ring preferably contains a 5- to 10-membered heterocyclic ring, and one having 1 to 5 hetero atoms is preferable, more preferably 1 to 3 and still more preferably 1 to 2 It is. The hetero atom is preferably O, N, S and / or P.

The compound containing an aromatic ring and the compound containing a heterocyclic ring may have one or more substituents. The substituent is not particularly limited. For example, -OH, -OR ⁷ , -COOH, -SO ₃ H, -PO ₃ H ₂ , -OPO ₃ H ₂ , -NH ₂ , -N (H) R ⁷ , And -NR ⁷ R ⁸ , an alkyl group having 1 to 10 carbon atoms, and the like (wherein, R ⁷ and R ⁸ are the same or different and each represents a hydrocarbon group, and the number of carbon atoms is preferably 1 to 4). ). The alkyl group having 1 to 10 carbon atoms may further have a phenyl group or a hydroxyphenyl group.

Examples of the compound containing an aromatic ring and the compound containing a heterocycle include phenol, cresol, resorcinol, nonylphenol, methoxyphenol, naphthol, methyl naphthol, butyl naphthol, bisphenol A, aniline, methyl aniline, hydroxy aniline, methoxy aniline, Examples include furfuryl alcohol.

The (poly) alkylene glycol chain is preferably composed of, for example, an oxyalkylene group having 2 to 18 carbon atoms. The carbon number of the oxyalkylene group is preferably 2 to 12, more preferably 2 to 8, more preferably 2 to 4, particularly preferably 2 or 3, that is, an oxyethylene group or an oxypropylene group.
When two or more oxyalkylene groups are present in the (poly) alkylene glycol chain, the addition form may be any addition form such as random addition, block addition, alternating addition, and the like.

The average chain length of the (poly) alkylene glycol chain is preferably 1 to 300 moles. That is, it is preferable that the average added mole number of the oxyalkylene group is 1 to 300. The lower limit is more preferably 2 or more, still more preferably 4 or more, particularly preferably 5 or more, most preferably 10 or more, and the upper limit is more preferably 280 or less, still more preferably 200 or less.

In the condensation reaction of the said phosphoric acid ester and an aldehyde compound, it is preferable to set these ratios (phosphate ester / aldehyde compound; mol%) to 10-1 to 1-10. Furthermore, when an aromatic compound and / or heterocyclic compound having a (poly) alkylene glycol chain is added to carry out the condensation reaction, the aromatic compound and / or heterocyclic ring is used with respect to 100 mol% of the aldehyde compound. It is preferable that the total amount of the formula compound and the phosphate ester be 1-1000 mol%. More preferably, it is 10-800 mol%.

The condensation reaction is not particularly limited, and a usual means may be used. For example, the method described in JP-A-2008-517080 can be mentioned.

The phosphoric acid based polymer obtained by the above polymerization and the phosphoric acid based condensate obtained by the above condensation can be used as it is as a surface coating agent for hydraulic inorganic particles and pozzolanic active inorganic particles, but it is possible to The polymer may be used after neutralizing with an alkaline substance. As the alkaline substance, inorganic salts such as hydroxides or carbonates of monovalent metals or divalent metals; ammonia; organic amines are suitable. Further, after the reaction is completed, the concentration can be adjusted if necessary.

The surface-coated inorganic particles of the present invention also have a relative surface concentration of carbon (C) with respect to silicon (Si) and calcium (Ca) per unit amount of organic dispersant on the particle surface (depth 0 nm) is 0.6. 10 to 10 is preferable. Thereby, the kneading time can be remarkably shortened, and the effect of the present invention that a hydraulic composition excellent in fluidity can be provided with high productivity can be more sufficiently exhibited. More preferably, it is 0.7-10, More preferably, it is 0.8-8, Especially preferably, it is 0.9-7, More preferably, it is 1.0-6, Most preferably, it is 1.1-5. Furthermore, it is preferable that the relative surface concentration of the average carbon (C) at a depth at 1 to 2 nm from the particle surface is 0.2 to 5 per unit amount of the organic dispersant, which is determined by the same method. is there. This makes it possible to more fully exhibit the effects of the present invention. More preferably, it is 0.2-4, More preferably, it is 0.25-3, Especially preferably, it is 0.3-3, More preferably, it is 0.35-2.5.

Here, “the relative surface concentration of carbon (C) with respect to silicon (Si) and calcium (Ca) per unit amount of organic dispersant” is a value obtained by the following method.
1. First, organic dispersion present in surface-coated inorganic particles (that is, hydraulic inorganic particles and / or pozzolanic active inorganic particles in which part or all of the surface is coated with an organic dispersant). Determine the amount of agent. The “amount of organic dispersant present in the surface-coated inorganic particles” means the ignition loss ratio at 150 ° C. obtained by heating the surface-coated inorganic particles in an electric furnace ((p) ) And the ignition loss rate at 450 ° C. (this is defined as (q)) (= p−q). The ignition loss rate at each temperature here means the mass residual rate (mass%) after heating at each temperature.
2 Next, after measuring XPS of the surface-coated inorganic particles to determine the value of the relative surface concentration of carbon (C) to silicon (Si) and calcium (Ca) (this is referred to as (x)), Value of relative surface concentration of carbon (C) with respect to silicon (Si) and calcium (Ca) by measuring XPS of inorganic particles after heating surface-coated inorganic particles in an electric furnace and heating at 550 ° C. for 3 hours (This is defined as (y)), and the difference between these (= xy) is calculated.
3. Divide the relative surface concentration difference (xy) determined in 2 above by the amount of organic dispersant (pq) present in the surface-coated inorganic particles determined in 1 above. Thus, the value determined by “(x−y) / (p−q)” can be expressed as “relative surface concentration of carbon (C) to silicon (Si) and calcium (Ca) per unit amount of organic dispersant ( z) ”.

In the present invention, in particular, when the relative surface concentration of carbon (C) to silicon (Si) and calcium (Ca) per unit amount of organic dispersant on the particle surface is measured by XPS, the relative surface of carbon (C) is measured. It is preferred that the concentration is 0.6 to 10 and the relative surface concentration of carbon (C) at an average depth of 1 to 2 nm from the particle surface is 0.2 to 5. By this, the kneading time can be remarkably shortened, and it is possible to further exhibit the function and effect of the present invention that the hydraulic composition having excellent fluidity can be provided with good productivity.

The surface-coated inorganic particles of the present invention preferably have a degree of hydration of 0.1 or less. Thereby, hydraulic particles having high hydration activity can be obtained without impairing the hydration characteristics of the hydraulic inorganic particles, and the effects of the present invention can be more fully exhibited. More preferably, it is 0.08 or less, More preferably, it is 0.06 or less. The lower limit of the hydration degree is preferably 0. That is, the degree of hydration is preferably 0 to 0.1, more preferably 0 to 0.08, and still more preferably 0 to 0.06.

In the present specification, “degree of hydration” means a value measured by the following method.
Heat the surface-coated inorganic particles (that is, hydraulic inorganic particles and / or pozzolanic active inorganic particles, in which part or all of the surface is coated with an organic dispersant) in an electric furnace, 450 The difference (= q−r) between the rate of loss on ignition in ° C. (this is denoted by (q)) and the rate of loss on ignition at 550 ° C. (hereinafter referred to as (r)) is taken as the degree of hydration.
The ignition loss ratio at each temperature herein means the mass residual ratio (mass%) after heating to each temperature.

[Hydraulic particles]
The present invention is also hydraulic particles containing the surface-coated inorganic particles of the present invention described above. Such hydraulic particles include, for example, those containing hydraulic inorganic particles and / or pozzolanic active inorganic particles whose surface is not coated, in addition to the above-mentioned surface-coated inorganic particles. In this case, the surface-coated inorganic particles are preferably 2% by mass or more, more preferably 5% by mass, with respect to 100% by mass of the total amount of the inorganic particles, in order to more fully express the effects of the surface-coated inorganic particles. % Or more, more preferably 10% by mass or more, particularly preferably 20% by mass or more, more preferably 30% by mass or more, and most preferably 100% by mass.

In particular, when the surface-coated inorganic particles are silica fume, the surface-coated inorganic particles contain 2 to 15% by mass with respect to 100% by mass of the total amount of the surface-coated inorganic particles and the inorganic particles whose surface is not coated. It is preferable that the content is 5 to 10% by mass.
When the surface-coated inorganic particles are fly ash or slag, the surface-coated inorganic particles are 10 to 70% by mass with respect to 100% by mass of the total amount of the surface-coated inorganic particles and the inorganic particles whose surface is not coated. It is preferably contained, more preferably 20 to 60% by mass, and still more preferably 30 to 50% by mass.

When the surface-coated inorganic particles are narrowly defined hydraulic inorganic particles (this surface-coated inorganic particles are also referred to as “surface-coated hydraulic inorganic particles”), silica fume or fly ash whose surface is not coated on the surface-coated inorganic particles , Slag can be mixed.
In this mixed system, when the inorganic particles whose surface is not coated is silica fume, the surface-coated hydraulic inorganic material is 100% by mass in total of the surface-coated hydraulic inorganic particles and the inorganic particles whose surface is not coated. The particles are preferably contained in an amount of 2 to 15% by mass, and more preferably 5 to 10% by mass.
In the above mixed system, when the inorganic particles whose surface is not coated is fly ash or slag, the surface is based on the total amount of 100 mass% of the surface-coated hydraulic inorganic particles and the inorganic particles whose surface is not coated. The content of the coated hydraulic inorganic particles is preferably 10 to 70% by mass, more preferably 20 to 60% by mass, and still more preferably 30 to 50% by mass.

[Method for producing surface-coated inorganic particles]
In the surface-coated inorganic particles of the present invention, at least one inorganic particle selected from the group consisting of hydraulic inorganic particles and pozzolanic active inorganic particles is dispersed in a solvent containing an organic dispersant, and then the solvent is retained. What is obtained by the manufacturing method including the process of leaving and pulverizing is preferable, and such a manufacturing method is one of this invention. In addition, the above-mentioned manufacturing method may further include other processes (for example, a washing process etc.) adopted by a usual manufacturing means.

In the production method, first, the inorganic particles are added to an organic dispersant and a solvent and dispersed in a solvent until a slurry is formed (also referred to as a dispersion step). The dispersing means is not particularly limited, and it is preferable to use a commonly used technique such as stirring (kneading).
In addition, about the said inorganic particle, it is as having mentioned above.

The said solvent should just contain the organic type dispersing agent and the said inorganic particle can disperse | distribute. For example, it is preferred to include an organic solvent or water. Thus, both the form in which the said solvent contains an organic solvent, and the form in which the said solvent contains water are suitable forms of this invention. Especially, in order to control the hydration of the said inorganic particle, it is preferable that the said solvent contains an organic solvent.
In addition, when the said solvent contains water and an organic solvent, it is suitable that water is 50 mass% or less with respect to 100 mass% of the total amount of the organic solvent and water in the said solvent. Thereby, it becomes possible to control the hydration of the hydraulic inorganic particles. The ratio of water to the total 100% by mass of the organic solvent and water is more preferably 30% by mass or less, still more preferably 10% by mass or less, particularly preferably 5% by mass or less, more preferably 1% by mass or less, most preferably It is most preferable that water is not substantially included, that is, when an organic solvent is used, water is not substantially included.

Examples of the organic solvent include alcohols such as methanol, ethanol, isopropanol, n-butanol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether and glycerin; ethers such as tetrahydrofuran, diethyl ether, dioxane, ethylene glycol dimethyl ether and diethylene glycol dimethyl ether And ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; esters such as ethyl acetate, butyl acetate, propylene glycol monomethyl ether acetate and 3-methoxybutyl acetate; aromatic hydrocarbons such as toluene, xylene and ethylbenzene Use one or more of chloroform, amides such as dimethylformaldehyde, etc. It can be. Preferably, alcohols, ethers, ketones and esters are used, and more preferably, alcohols or mixed solvents of alcohols and other organic solvents.

In the dispersion step, it is preferable that the amount of the solvent includes an organic dispersant and is an amount capable of dispersing the inorganic particles. Specifically, it is preferable to use 5 to 2000 parts by weight of the solvent with respect to 100 parts by weight of the inorganic particles to be surface-coated. More preferably 10 parts by weight or more, still more preferably 14 parts by weight or more, more preferably 300 parts by weight or less, still more preferably 200 parts by weight or less, particularly preferably 100 parts by weight or less, most preferably 50 parts by weight It is as follows. If the amount of the solvent is small, the inorganic particles cannot be sufficiently dispersed and the inorganic particles cannot be prevented from agglomerating, so that the kneading time cannot be shortened. If the amount of the solvent is too large, a large amount of energy and time are required for distilling off the solvent, which is not economical.
The amount of the solvent is preferably 500 to 100,000 parts by weight with respect to 100 parts by weight of the organic dispersant in the surface-coated inorganic particles. More preferably 1000 parts by weight or more, further preferably 1400 parts by weight or more, particularly preferably 2000 parts by weight or more, most preferably 2300 parts by weight or more, more preferably 50000 parts by weight or less, still more preferably 30000 parts by weight. The content is particularly preferably 20000 parts by weight or less.

The amount of the organic dispersant used may be appropriately determined in consideration of the physical properties of the inorganic particles, the dispersibility of the surface-coated inorganic particles to be obtained, etc. It is preferable that the content be 0.01 to 10 parts by weight. Within this range, the inorganic particles can be more sufficiently and efficiently coated, and the dispersibility of the surface-coated inorganic particles obtained is more fully exhibited. More preferably, it is 0.01-5 weight part, More preferably, it is 0.05-4 weight part, Especially preferably, it is 0.05-3 weight part.

In the said manufacturing method, a solvent is distilled off after the said dispersion | distribution process, and it pulverizes (it also calls a powderization process). The means for distilling off the solvent is not particularly limited. For example, the solvent may be volatilized by heating or drying, and it is also suitable to distill off the solvent under reduced pressure. The powdering means is not particularly limited, and pulverization may be performed using a raw material pulverizer or the like.
In addition, it is suitable to adjust the particle size of the surface-coated inorganic particle obtained using a sieve (for example, JIS test sieve etc.) after a pulverization process.

[Surface coating agent]
The present invention also provides a surface coating agent for inorganic particles used to obtain the surface-coated inorganic particles, wherein the inorganic particles are at least one selected from the group consisting of hydraulic inorganic particles and pozzolanic active inorganic particles. The surface coating agent is also a surface coating agent containing at least one selected from the group consisting of a sulfonic acid group-containing compound and / or a phosphoric acid group-containing compound.
As described above, the sulfonic acid group-containing compound and the phosphoric acid group-containing compound have good adsorptivity to the surface of the hydraulic inorganic particles and pozzolanic active inorganic particles, and can impart dispersibility after the surface coating, It is suitable as a surface coating agent for obtaining the surface-coated inorganic particles.
The sulfonic acid group-containing compound and the phosphoric acid group-containing compound are as described above.

The surface coating agent also has an effect of assisting the pulverization of the inorganic particles as well as the surface coating effect of the inorganic particles. Therefore, it is also suitable to use the above-mentioned surface coating agent as a grinding aid in the grinding process during the production of inorganic particles. However, in order to achieve the present invention, it is necessary for the particles to be dispersed at the time of grinding of the inorganic particles, and it is preferable to grind in a form containing the above-mentioned fixed amount of solvent.

(Hydraulic composition)
The surface-coated inorganic particles of the present invention can be mixed with water to give a hydraulic composition. Such a hydraulic composition comprising the surface-coated inorganic particles and water is one of the preferred embodiments of the present invention. Examples of the hydraulic composition include cement paste, mortar, concrete, plaster and the like.

The hydraulic composition may contain aggregates such as fine aggregate (sand, etc.) and coarse aggregate (crushed stone, etc.) as necessary. Specifically, for example, gravel, crushed stone, granulated slag, recycled aggregate, etc., siliceous, clay, zircon, high alumina, silicon carbide, graphite, chrome, chromic, magnesia Fireproof aggregates such as can also be used.

The hydraulic composition may also contain a dispersant, if necessary. Since the surface-coated inorganic particles of the present invention are partially or wholly coated with an organic dispersant, the hydraulic composition including the surface-coated inorganic particles has sufficient fluidity even without a separate dispersant. Although it can be shown, if necessary, it may further contain a dispersant. As the dispersant, one or two or more commonly used ones can be used. Specific examples are as described above.

The hydraulic composition may further contain hydraulic inorganic particles and / or pozzolanic active inorganic particles whose surface is not coated, in addition to the surface-coated inorganic particles, if necessary. In this case, the surface-coated inorganic particles are preferably 2% by mass or more, more preferably 5% by mass, with respect to 100% by mass of the total amount of the inorganic particles, in order to more fully express the effects of the surface-coated inorganic particles. % Or more. Further, it is more preferably 10% by mass or more, still more preferably 30% by mass or more, particularly preferably 50% by mass or more, more preferably 80% by mass or more, and most preferably 100% by mass.

In the hydraulic composition, the unit water amount per 1 m ^3, the total amount of hydraulic particles (referred to as B) (the amount used B), and the water / B ratio (mass ratio) are unit water amount = 100 to 185 kg / m ^3, use B amount = 250~800kg / ^{m 3,} it is preferable that the water / B ratio = 0.1 to 0.7. More preferably, the unit water amount is 120 to 175 kg / m ³ , the used B amount is 270 to 800 kg / m ³ , and the water / B ratio is 0.1 to 0.65, and can be used widely from poor blends to rich blends. However, it is also very effective for high-strength concrete having a unit water amount of 500 kg / m ³ or more and ultrahigh-strength concrete having 900 kg / m ³ or more. Further, in the present invention, a hydraulic composition having a low water / B ratio has an effect that the kneading time is fast and excellent fluidity can be exhibited. It can be confirmed more sufficiently when the / B ratio is 0.5 or less. The water / B ratio is more preferably 0.4 or less, still more preferably 0.35 or less, still more preferably 0.3 or less, particularly preferably 0.25 or less, most preferably 0.2 or less.

The above hydraulic composition is also effective for, for example, ready mixed concrete, concrete for secondary concrete product (precast concrete), centrifugal formed concrete, vibration-compacted concrete, steam cured concrete, shot concrete, etc. High fluidity of medium fluidity concrete (concrete with slump value of 22-25cm), high fluidity concrete (concrete with slump value of 25cm or more, slump flow value of 50-70cm), self-filling concrete, self-leveling material, etc. It is also effective for required mortar and concrete.

The hydraulic composition may further include one or more of those usually used as a cement additive (material). For example, water-soluble polymer materials exemplified in International Publication No. 2014/010572 [0066] to [0072]; polymer emulsion; retarder; early strengthening agent / accelerator; mineral oil-based antifoaming agent; Foaming agent; fatty acid-based antifoaming agent; fatty acid ester-based antifoaming agent; oxyalkylene-based antifoaming agent; alcohol-based antifoaming agent; amide-based antifoaming agent; phosphate ester-based antifoaming agent; Silicone antifoaming agent; AE agent; other surfactants; waterproofing agent; rust preventive agent; cracking reducing agent; expansion material; cement wetting agent; thickening agent; separation reducing agent; Agents, self-leveling agents, rust preventives, coloring agents, fungicides, and the like.

[Method of producing hydraulic composition]
A method for producing a hydraulic composition using the surface-coated inorganic particles is also one preferred embodiment of the present invention. The production method preferably includes, for example, a step of mixing the surface-coated inorganic particles, water, and the other components added as needed, and the other steps are not particularly limited. In the present invention, by using the above surface-coated inorganic particles, a hydraulic composition exhibiting high fluidity can be easily obtained in a short time. Therefore, the method for producing such a hydraulic composition includes a hydraulic composition. It is very useful in the technical field which uses a thing.
In addition, the technique of the present invention can be applied to inorganic particles that react with water such as gypsum to be cured, and is within the scope of the invention.

Since the surface-coated inorganic particles of the present invention are configured as described above, the kneading time can be significantly shortened, and the productivity of the hydraulic composition can be significantly improved. In addition, since the hydraulic composition using such surface-coated inorganic particles is extremely excellent in fluidity, it contributes a great deal in the field of civil engineering and construction which handles concrete. Furthermore, the surface coating agent containing at least one selected from the group consisting of a sulfonic acid group-containing compound and / or a phosphoric acid group-containing compound is adsorbed and adhered to hydraulic inorganic particles and pozzolanic active inorganic particles, and It is particularly suitable for use as a surface coating for hydraulic inorganic particles or pozzolanic active inorganic particles, since it is extremely excellent in particle dispersibility after adsorption and deposition (ie after surface coating).

In Experimental example 4-1, the time of cement and water injection | throwing is made into 0 second (s), and it is the photograph which image | photographed the state of the hydraulic composition until it stops stirring every 20 to 60 second (s). In Experiment 4-6, the time of cement and water injection | throwing is set to 0 second (s), and it is the photograph which image | photographed sequentially the condition of the hydraulic composition until it stops stirring.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. The weight average molecular weight of the polymer obtained in the preparation example is measured by the above-described GPC measurement method, and the particle diameter of the particles and the relative surface concentration of C _{1s to} the surface Si _2p and Ca _2p are the methods described above. It measured by. Moreover, in the following Production Examples 1 to 4 and Test Examples 4 to 4-6, kneading is performed at 1 speed (139 rpm) using a Hobert mixer (N-50; hereinafter also referred to as Hobert mixer). It was. The flow value of the cement paste obtained in the test example was measured as follows.

<Measurement of flow value>
The prepared paste was packed in a hollow cylindrical container having a diameter of 55 mm and a height of 50 mm placed on a horizontal table, and then the hollow cylindrical container was lifted vertically, and the diameter of the paste spread on the table was adjusted to 2 It measured about direction and made this average value the flow value.

Preparation Example 1 (Preparation of Phosphoric Acid Dispersant (1))
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, 200 g of ion-exchanged water was charged, the reaction apparatus was purged with nitrogen, and the temperature was raised to 80 ° C. Next, 65.9 g of methoxypolyethylene glycol methacrylate (addition mole number of ethylene oxide: 23 mol), mono (2-hydroxyethyl) methacrylic acid phosphate and di-[(2-hydroxyethyl) methacrylic acid] ester An aqueous solution prepared by dissolving 40.6 g of a mixture (Light Ester P-1M, manufactured by Kyoeisha Chemical Co., Ltd.) and 1.7 g of 3-mercaptopropionic acid in 97.0 g of ion-exchanged water was added dropwise over 1.5 hours. At the same time, an aqueous solution in which 4.7 g of ammonium persulfate was dissolved in 45 g of ion-exchanged water was added dropwise over 1.5 hours. After completion of the dropwise addition, stirring was continued at 80 ° C. for 1 hour, and an aqueous solution in which 2.4 g of ammonium persulfate was dissolved in 15 g of ion-exchanged water was dropped over 1 hour. After completion of the dropwise addition, stirring was continued at 80 ° C. for 1.5 hours, and then the polymerization reaction was terminated to obtain an aqueous solution of a phosphoric acid copolymer having a weight average molecular weight (Mw) of 20000. A sodium hydroxide aqueous solution was added to the obtained phosphoric acid copolymer aqueous solution, neutralized to pH 7, dried under reduced pressure (50 mmHg) at 50 ° C., pulverized, and 70 mesh in the JIS test sieve mesh conversion table was obtained. It was prepared as a powdery phosphoric acid copolymer passing through. This is referred to as a phosphoric acid based dispersant (1).

Preparation Example 2 (Preparation of Phosphoric Acid Dispersant (2))
In a glass reaction vessel equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube, and a reflux condenser, 13.8 g of ion exchanged water, polyethylene glycol (addition mole of ethylene oxide: 120 moles) monophenyl ether 250.0 g Then, 29.7 g of phenylphosphonic acid and 9.2 g of sulfuric acid were charged, the reactor was purged with nitrogen under stirring, and the temperature was raised to 100 ° C. Next, an aqueous solution obtained by diluting 4.23 g of formaldehyde with 7.86 g of ion-exchanged water was added dropwise over 1 hour. After completion of the dropping, stirring was continued at 100 ° C. for 1 hour to complete the polycondensation reaction, and an aqueous solution of a phosphoric acid-based condensate having a weight average molecular weight (Mw) of 25000 was obtained. Sodium hydroxide aqueous solution is added to the obtained phosphoric acid-based condensate aqueous solution, neutralized to pH 7, dried at 50 ° C. under reduced pressure (50 mmHg), pulverized, and passed through 70 mesh in the JIS test sieve mesh conversion table. It was prepared as a powdered phosphoric acid condensation product. This is referred to as a phosphoric acid based dispersant (2).

Production Example 1 (Production of Surface-Coated Inorganic Particles (1))
Ube-Mitsubishi Cement Co., Ltd. 700 g of silica fume cement is put into a Hobert mixer (N-50), dried and powdered to 14 g of a sulfonic acid dispersant (Mighty 150, manufactured by Kao Corporation) with respect to the cement solid content. 0 mass%) 119 g of the dissolved aqueous solution (105 g of water, water / cement mass ratio = 0.15) was introduced into the mixer. After the addition, after stirring for 300 seconds at 1st speed, the stirring was stopped, and the paste adhering to the wall of the container was scraped off over 30 seconds. After the aqueous solution was charged, switching was made to 2nd speed 330 seconds after the addition of the aqueous solution, the stirring was restarted, and after stirring for 90 seconds, the stirring was stopped. The obtained paste was transferred to a vat and dried under reduced pressure (50 mmHg) at 50 ° C. to completely distill off water (partially remained as bound water). After drying, pulverization is performed, the particle size is adjusted using a sieve corresponding to 70 mesh in the JIS test sieve mesh conversion table, and the silica fume cement (surface-coated inorganic particles (1) is coated with a sulfonic acid dispersant). Obtained).

Production Example 2 (Production of Surface-Coated Inorganic Particles (2))
700 g of silica fume cement manufactured by Ube-Mitsubishi Cement Co., Ltd. was charged into a Hobart mixer (N-50), and stirred at first speed for 300 seconds. At the same time as stirring, 35 g (21 g of water, 21 g of water) of an aqueous solution in which 14 g (2.0% by mass with respect to cement solids) of a sulfonic acid based dispersant (Mighty 150, manufactured by Kao) dried and powdered was dissolved The cement mass ratio = 0.03) was sprayed on the cement in the mixer over 300 seconds to coat the cement particles with the sulfonic acid dispersant. Stirring was stopped, the obtained powder was transferred to a vat, drying under reduced pressure (50 mmHg) was performed at 50 ° C., and the evaporable water was completely distilled off (remains partially as bound water). After drying, the particle size is adjusted using a sieve corresponding to 70 mesh in the JIS test sieve mesh conversion table to obtain silica fume cement (also referred to as surface-coated inorganic particles (2)) whose surface is coated with a sulfonic acid dispersant. It was.

Production Example 3 (Production of Surface-Coated Inorganic Particles (3))
700 g of silica fume cement made by Ube-Mitsubishi Cement Co., Ltd. was charged into a Hobart mixer (N-50), and 7 g (1.0% by mass with respect to the solid content of the cement) of the phosphoric acid dispersant (1) obtained in Preparation Example 1 was dissolved. 112 g of the prepared aqueous solution (105 g of water, water / cement mass ratio = 0.15) was introduced into the mixer. After the addition, after stirring for 300 seconds at 1st speed, the stirring was stopped, and the paste adhering to the wall of the container was scraped off over 30 seconds. After the aqueous solution was charged, switching was made to 2nd speed 330 seconds after the addition of the aqueous solution, the stirring was restarted, and after stirring for 90 seconds, the stirring was stopped. The obtained paste was transferred to a vat and dried under reduced pressure (50 mmHg) at 50 ° C. to completely distill off water (partially remained as bound water). After drying, pulverization is performed, the particle size is adjusted using a sieve corresponding to 70 mesh in the JIS test sieve mesh conversion table, and the silica fume cement (surface-coated inorganic particles (3)) is coated with a phosphoric acid dispersant. Obtained).

Production Example 4 (Production of Surface-Coated Inorganic Particles (4))
700 g of silica fume cement manufactured by Ube Mitsubishi Cement Co., Ltd. was charged into a Hobart mixer (N-50), and 3.5 g of phosphoric acid dispersant (2) obtained in Preparation Example 2 (0.5% by mass with respect to the solid content of cement). ) 108.5 g of the dissolved aqueous solution (105 g of water, water / cement mass ratio = 0.15) was put into the mixer. After the addition, after stirring for 300 seconds at 1st speed, the stirring was stopped, and the paste adhering to the wall of the container was scraped off over 30 seconds. After the aqueous solution was charged, switching was made to 2nd speed 330 seconds after the addition of the aqueous solution, the stirring was restarted, and after stirring for 90 seconds, the stirring was stopped. The obtained paste was transferred to a vat and dried under reduced pressure (50 mmHg) at 50 ° C. to completely distill off water (partially remained as bound water). After drying, pulverization is performed, the particle size is adjusted using a sieve corresponding to 70 mesh in the JIS test sieve mesh conversion table, and the silica fume cement (surface-coated inorganic particles (4)) is coated with a phosphoric acid dispersant. Obtained).

Test Examples 1-1 to 1-4
For each of the surface-coated inorganic particles obtained in Production Examples 1 to 4, the relative surface concentration of C _1s to Si 2 _p and Ca 2 _p on the particle surface was measured by XPS. The results are shown in Table 1.

Test Example 1-5
The relative surface concentration of C _1s to Si 2 _p and Ca 2 _p on the particle surface of the silica fume cement manufactured by Ube-Mitsubishi Cement Co., Ltd., which is a commercially available product, was measured by XPS. The results are shown in Table 1.

Test Example 1-6
Dried to powdered sulfonic acid dispersant (Mighty 150, Kao Corporation) and 0.14 g, the premixed cement mixed in Ube Mitsubishi Cement Corp. silica fume cement 7 g, C for _{Si 2p} and _{Ca 2p} the particle surface The relative surface concentration of _{1 s} was measured by XPS. The results are shown in Table 1.

Test Examples 2-1 to 2-6
Surface-coated silica fume cement (surface-coated inorganic particles (1) to (4)) obtained in Production Examples 1 to 4, Ube-Mitsubishi Cement Co., Ltd. non-surface-coated silica fume cement or dried and powdered sulfonic acid Premix cement in which 0.14 g of dispersant (Mighty 150, manufactured by Kao Corporation) is mixed with 7 g of silica fume cement manufactured by Ube-Mitsubishi Cement Co., Ltd., using a precision balance in the crucible, weighing to the fourth decimal place (about 5 g) did. A crucible containing the weighed silica fume cement was placed in an electric furnace (KM-600 manufactured by ADVANTEC), and heated at 150 ° C. under a nitrogen atmosphere (flow rate 2 L / min) for 2 hours. After 2 hours, the crucible is taken out of the electric furnace, allowed to cool to room temperature in a desiccator, the silica fume cement is weighed with a precision balance to the fourth decimal place, and after heating from the ratio of the preparation amount to the remaining amount The residual rate (p) was measured. Subsequently, the same crucible was put into the electric furnace again and heated at 450 ° C. in a nitrogen atmosphere (flow rate 2 L / min) for 2 hours. After 2 hours, the mixture was allowed to cool in the desiccator, and the residual rate (q) after heating at 450 ° C. was measured. From the difference between the residual rate (p) at 150 ° C. and the residual rate (q) at 450 ° C., the content (= p−q) of the organic dispersant in the silica fume cement was calculated.
Subsequently, the same crucible was put into the electric furnace again and heated at 550 ° C. in a nitrogen atmosphere (flow rate 2 L / min) for 2 hours. After 2 hours, the mixture was allowed to cool in a desiccator, and the residual ratio (r) after heating at 550 ° C. was measured. From the difference between the residual rate (q) at 450 ° C. and the residual rate (r) at 550 ° C., the degree of hydration (= q−r) of chemically bound water in silica fume cement was calculated. The results are shown in Table 2.

Test Example 3-1
For the surface-coated inorganic particles (1) finally obtained in Test Example 2-1 (after 550 ° C. loss on ignition; y), the relative surface concentration of C _1s with respect to Si _2p and Ca _2p on the particle surface was measured by XPS. It was measured. The results are shown in Table 3. The relative surface concentration of the surface-coated inorganic particles (1) (before loss on ignition; x) before heating and the “(p−q)” value shown in Table 2 are also shown in Table 3.
From these results, the relative surface concentration (z) of carbon (C) to silicon (Si) and calcium (Ca) per unit amount of organic dispersant was calculated. The results are shown in Table 3.
Test examples 3-2 to 3-6 were similarly analyzed. The results are shown in Table 3.

Test Example 4-1
500 g of the silica fume cement (surface-coated inorganic particles (1)) obtained in Production Example 1 was put into a Hobert mixer (N-50), and 75 g of water was put into the mixer (water / cement mass ratio = 0.15). After the addition, after stirring for 300 seconds at 1st speed, the stirring was stopped, and the paste adhering to the wall of the container was scraped off over 30 seconds. After 330 seconds from the addition of water, stirring was resumed at the second speed and stirring was continued for 90 seconds. The time until cement and water were added was set to 0 second, and the time until the softness of the paste became visually constant was described as “kneading time” in Table 4. Moreover, the photograph which image | photographed the state at the time of stirring with time is shown in FIG. Table 4 shows the result of measuring the flow value of the obtained paste.

Test Example 4-2
500 g of the silica fume cement (surface-coated inorganic particles (2)) obtained in Production Example 2 was put into a Hobert mixer (N-50), and 75 g of water was put into the mixer (water / cement mass ratio = 0.15). After the addition, after stirring for 300 seconds at 1st speed, the stirring was stopped, and the paste adhering to the wall of the container was scraped off over 30 seconds. After 330 seconds from the addition of water, stirring was resumed at the second speed and stirring was continued for 90 seconds. The time for the cement and water to be added was 0 seconds, and the time until the softness of the paste was visually constant was described in Table 4 as "kneading time". Table 4 shows the result of measuring the flow value of the obtained paste.

Test Example 4-3
500 g of the silica fume cement (surface-coated inorganic particles (3)) obtained in Production Example 3 was put into a Hobert mixer (N-50), and 75 g of water was put into the mixer (water / cement mass ratio = 0.15). After the addition, after stirring for 300 seconds at 1st speed, the stirring was stopped, and the paste adhering to the wall of the container was scraped off over 30 seconds. After 330 seconds from the addition of water, stirring was resumed at the second speed and stirring was continued for 90 seconds. The time until cement and water were added was set to 0 second, and the time until the softness of the paste became visually constant was described as “kneading time” in Table 4. Table 4 shows the result of measuring the flow value of the obtained paste.

Test Example 4-4
500 g of the silica fume cement (surface-coated inorganic particles (4)) obtained in Production Example 4 was put into a Hobert mixer (N-50), and 75 g of water was put into the mixer (water / cement mass ratio = 0.15). After the addition, after stirring for 300 seconds at 1st speed, the stirring was stopped, and the paste adhering to the wall of the container was scraped off over 30 seconds. After 330 seconds from the addition of water, stirring was resumed at the second speed and stirring was continued for 90 seconds. The time until cement and water were added was set to 0 second, and the time until the softness of the paste became visually constant was described as “kneading time” in Table 4. Table 4 shows the result of measuring the flow value of the obtained paste.

Test Example 4-5
Dissolve 500 g of silica fume cement manufactured by Ube Mitsubishi Cement Co., Ltd. into a Hobert mixer, and dry it to make a powder, and dissolve 10 g (2.0 mass% with respect to cement solid content) of sulfonic acid dispersant (Mighty 150: manufactured by Kao) The resulting aqueous solution (85 g of water, water / cement mass ratio = 0.15) was introduced into the mixer. After the addition, after stirring for 300 seconds at 1st speed, the stirring was stopped, and the paste adhering to the wall of the container was scraped off over 30 seconds. After 330 seconds from the addition of water, stirring was resumed at the second speed and stirring was continued for 90 seconds. The time until cement and water were added was set to 0 second, and the time until the softness of the paste became visually constant was described as “kneading time” in Table 4. In addition, Table 4 shows the results of measuring the flow value of the obtained paste.

Test Example 4-6
14 g of a dried and powdered sulfonic acid-based dispersant (Mighty 150: manufactured by Kao Corporation) was mixed with 700 g of silica fume cement manufactured by Ube Mitsubishi Cement Co., Ltd. to obtain a premix cement containing a powdery sulfonic acid-based dispersant . 500 g of this premix cement was put into a Hobert mixer (N-50), and 75 g of water was put into the mixer (water / cement mass ratio = 0.15). After the addition, a cement paste was prepared in the same manner as in Test Example 4-1. The time until cement and water were added was set to 0 second, and the time until the softness of the paste became visually constant was described as “kneading time” in Table 4. Moreover, the photograph which image | photographed the state at the time of stirring over time is shown in FIG. Table 4 shows the result of measuring the flow value of the obtained paste.

From Table 4 above, the following was confirmed.
In Test examples 4-1 to 4-6, the water / cement mass ratio (W / C) was 0.15 (15%), which was a very low condition. In addition, it is W / C = 0.45-0.6 (45-60%) in general concrete, and W / C = 0.3 (30%) also in high-strength concrete.

Test Examples 4-1, 4-3, and 4-4 are examples in which the surface-coated inorganic particles (1), (3), and (4) each having a predetermined relative surface concentration within the range defined in the present invention are used. However (see Table 1), in this case, despite the very low W / C, the time required to develop a certain fluidity is about 80 to 90 seconds, and a significant kneading time is required. It turned out that shortening could be achieved. On the other hand, Test Example 4-5 is an example using normal silica fume cement, and this cement has a predetermined relative surface concentration below the range specified in the present invention (see Table 1). In this case, it took 240 seconds for the cement paste to exhibit a certain level of fluidity (that is, until the fluidity was stabilized).
The organic dispersant used as a surface coating agent for cement particles in obtaining the surface-coated inorganic particles (1) in Production Example 1 is the same as the dispersant introduced into cement in Test Example 4-5. Therefore, it was found that the shortening effect of the kneading time confirmed in Test Example 4-1 was attributed to the difference in the carbon content ratio of the cement particle surface.

Test Example 4-6 is an example using a premix cement obtained by mixing the same organic dispersant as used in Production Example 1 and Test Example 4-5 with cement particles as it is in powder form. The premix cement has a predetermined relative surface concentration below the range defined in the present invention (see Table 1). In this case, the kneading time was longer than in Test Example 4-5. Therefore, it was found that powderizing the organic dispersant does not contribute to shortening of the kneading time, but rather the kneading time is prolonged.

Test Example 4-2 is an example in which the silica fume cement obtained in Production Example 2 (surface-coated inorganic particles (2)), that is, the surface-coated cement obtained by spraying an aqueous solution containing a dispersant onto the cement is used. From the results of this example, in the method of coating by spraying a small amount of aqueous solution as in the surface-coated inorganic particles (2), the dispersing agent is not sufficiently coated on the cement surface, so that aggregation of the cement particles can be prevented. It was considered that the kneading time was not shortened.

In Test Examples 4-1 to 4-4, after each of solid surface-coated inorganic particles is obtained in Production Examples 1 to 4, water is added to prepare a paste. In general, since inorganic particles such as cement particles are circulated in a solid form, the time taken to obtain the one (solid surface-coated inorganic particles) in a state of being subjected to this circulation is not included in the kneading time. . The surface-coated inorganic particles of the present invention have an extremely remarkable effect in that the production time for obtaining a hydraulic composition can be significantly shortened only by using the same.

From FIGS. 1 and 2, the following was confirmed.
In Test Example 4-1, since the organic dispersant is coated on the inorganic particles, aggregation of the inorganic particles did not occur immediately after the addition of water. As aggregates of inorganic particles were not constructed, water quickly spread to the inorganic particles, and in a short time (90 seconds), an equilibrium state of dispersion and aggregation was reached. On the other hand, in Test Example 4-6, as shown in FIG. 2, immediately after the addition of the water containing the organic dispersant, aggregation of the inorganic particles occurs instantaneously, and the water containing the dispersant is contained in the aggregate. It took 300 seconds until it became constrained and became lumpy, and dispersion and aggregation reached an equilibrium state.

Claims (10)

A part or all of the surface of at least one inorganic particle selected from the group consisting of hydraulic inorganic particles and pozzolanic active inorganic particles is coated with an organic dispersant;
When the relative surface concentration of carbon (C) with respect to silicon (Si) and calcium (Ca) on the particle surface was measured by XPS, the relative surface concentration of carbon (C) was 0.50 to 50, and from the particle surface The relative surface concentration of carbon (C) having an average depth of 1 to 2 nm is 0.25 to 50,
The surface-coated inorganic particles, wherein the organic dispersant is at least one selected from the group consisting of a sulfonic acid group-containing compound and / or a phosphoric acid group-containing compound. The surface-coated inorganic particles have a carbon (C) content as measured by XPS of relative surface concentration of carbon (C) with respect to silicon (Si) and calcium (Ca) per unit amount of organic dispersant on the particle surface. The relative surface concentration is 0.6 to 10 and the relative surface concentration of carbon (C) having an average depth of 1 to 2 nm from the particle surface per unit amount of the organic dispersant is 0.00. The surface-coated inorganic particles according to claim 1, wherein the surface-coated inorganic particles are 25 to 5. The surface-coated inorganic particles according to claim 1 or 2, wherein the surface-coated inorganic particles have a degree of hydration of 0.1 or less. The surface-coated inorganic particles according to any one of claims 1 to 3, wherein the inorganic particles are at least one selected from the group consisting of cement, silica fume, fly ash and slag. A hydraulic particle comprising the surface-coated inorganic particle according to claim 1. The manufacturing method of the hydraulic composition characterized by using the surface coating inorganic particle in any one of Claims 1-4. A method for producing the surface-coated inorganic particles according to claim 1,
In the production method, at least one inorganic particle selected from the group consisting of hydraulic inorganic particles and pozzolanic active inorganic particles is dispersed in a solvent containing an organic dispersant, and then the solvent is distilled off to obtain a powder. Including the process of
The method for producing surface-coated inorganic particles, wherein the organic dispersant is at least one selected from the group consisting of a sulfonic acid group-containing compound and / or a phosphoric acid group-containing compound. The method for producing surface-coated inorganic particles according to claim 7, wherein the solvent contains an organic solvent. The method for producing surface-coated inorganic particles according to claim 7, wherein the solvent contains water. A surface coating agent for inorganic particles used to obtain the surface-coated inorganic particles according to any one of claims 1 to 4,
The inorganic particles are at least one selected from the group consisting of hydraulic inorganic particles and pozzolanic active inorganic particles,
The surface coating agent comprises at least one selected from the group consisting of a sulfonic acid group-containing compound and / or a phosphoric acid group-containing compound.