JP5051990B2 - Ultra-fast-hardening cement composition and dispersant for super-fast-hardening cement composition - Google Patents

Description

The present invention relates to a cement composition having super-hardness and a dispersant for a super-fast-hardness cement composition. More specifically, the present invention relates to an ultrafast cement composition and a dispersant for an ultrafast cement composition that can be used for repairs and emergency construction in the civil engineering / architecture field and can improve workability while maintaining rapid curing.

The ultrafast cement composition is manufactured by mixing ultrafast cement, water, fine aggregate, coarse aggregate, and the like. The super fast-hardening cement composition is excellent in fast-curing properties and gives a cured product with excellent strength and durability. Therefore, various repairs, reinforcements, emergency works, and concrete products for building outer wall materials and building structures, etc. Is widely used. Such an ultra-fast-hardening cement composition is required not only to be excellent in quick-hardness but also to have initial fluidity and fluidity that does not hinder work, and to be excellent in strength and durability after curing. Furthermore, since an ultrafast cement composition is frequently used in winter when the curing rate is low, it is required to exhibit these characteristics even in a low-temperature atmosphere.

In cementitious cement compositions, cement containing calcium aluminate as a fast-hardening component (superfast-hardening cement) is generally used, and calcium aluminate as a fast-hardening component is rapidly hydrated with kneaded water. It is known that excellent initial strength expression is exhibited. On the other hand, due to the rapid hydration reaction of calcium aluminates, the fluidity of the cement composition is significantly reduced and kneading becomes difficult. There has been a demand for improving workability with sufficient pot life. In addition, in such a cement composition, reducing the unit water amount contained in the cement composition will improve the performance of the cured product, thus improving workability without increasing the unit water amount of kneaded water. Was demanded.

To date, various dispersants have been added to improve the properties such as initial fluidity and pot life of the ultrafast-hardening cement composition, and in order to improve the strength of the cured product, The amount of unit water contained therein is reduced.
Examples of the dispersant contained in the conventional super-hard cement composition include a cement dispersant mainly composed of a formalin condensate of naphthalene sulfonate and a formalin condensate of melamine sulfonate, and a polymethacrylic acid cement dispersant. It has been known.
However, when the additive amount exceeds a certain amount, dispersants mainly composed of naphthalene sulfonate formalin condensate or melamine sulfonate formalin condensate will reach the peak in cement dispersion effect and fluidity improvement effect. Therefore, there has been a demand for a cement dispersant that can realize the required high fluidity, low unit water content, initial fluidity, pot life, dispersibility, and the like.

In addition, it is necessary to have sufficient fluidity during the working period, but a dispersant mainly composed of a formalin condensate of naphthalene sulfonate or a formalin condensate of melamine sulfonate does not have a sufficient pot life. In some cases, it is known that a set retarder needs to be added in order to maintain the fluidity realized by using a dispersant for a period required for the work. However, the setting retarder, especially at low temperatures, may reduce the initial strength development of the super fast-hardening cement composition if the added amount is large. Even so, there has been a demand for a super-hard setting cement composition capable of maintaining fluidity for a time required for work. Furthermore, since the formalin used in the synthesis process may remain in these cement dispersants, there has been a demand for an ultrafast cement composition that is environmentally preferable.

Polycarboxylic acid-based cement dispersants are generally known to have a higher dispersion effect than cement dispersants whose main component is a formalin condensate of naphthalene sulfonate or a formalin condensate of melamine sulfonate. . When used for general Portland cement, the polycarboxylic acid-based admixture exhibits excellent dispersion performance, and the cement composition is remarkably fluidized without changing the unit amount of water, or maintains a constant fluidity. It is possible to significantly reduce the unit water volume. For example, a hydraulic substance mainly composed of calcium aluminate having a CaO / Al ₂ O ₃ molar ratio of 0.5 to 4.0, and a cement dispersant mainly composed of a polycarboxylic acid polymer. A cement composition is disclosed, and in the examples, a methacrylic acid-based cement dispersant is used (for example, see Patent Document 1).

When a polycarboxylic acid-based cement dispersant is applied to a super-fast-hardening cement composition, a method for producing a high-fluidity fast-hardening cement composition in which polycarboxylic acid (salt) is added to paste, mortar, or concrete having fast-hardening properties (See, for example, Patent Document 2) and a powdery super-hard cement composition including a super-fast hard cement and a powdered polycarboxylic acid-based cement dispersant is disclosed, and in the examples, a methacrylic acid-based cement dispersant is used. (For example, refer to Patent Document 3). However, it not only excels in fast curing, high fluidity, low unit water content, initial fluidity, dispersibility, and strength of the resulting cured product, but also exhibits excellent initial strength even in a low-temperature atmosphere, resulting in fluid retention. There was room for devising a super-fast hardened cement composition that is excellent, has sufficient pot life, and has good workability.
JP 11-217250 A (page 2-4) JP-A-7-17749 (page 1-2) JP 2000-34159 A (page 1-2)

The present invention has been made in view of the above situation, and has an object to provide an ultrafast cement composition having excellent fluidity and initial strength development in a low temperature atmosphere and excellent fluidity retention. To do.

The inventors of the present invention have made various investigations on the ultrafast-hardening cement composition, and noticed that calcium aluminates are useful as fast-hardening components, and the cement dispersion containing a polyacrylic acid-based copolymer having a polyethylene oxide chain. When used together with a cement dispersant containing polyacrylic acid and / or its salt (polyacrylic acid type dispersant), conventional naphthalene cement dispersants and general polycarboxylic acid type (mainly methacrylic acid type) As compared with other cement dispersants, it was found that good fluidity was obtained with a small amount of addition, and that fluidity could be maintained without increasing the amount of setting retarder added, and that excellent fluidity retention was exhibited. . In addition, in a low-temperature atmosphere, not only exhibits excellent fast-curing properties, fluidity, and initial strength, but also has excellent fluidity and retains a sufficient pot life, so that it has excellent workability. I found what I could do and came up with the idea that I could solve the above problems. Furthermore, it has been found that it can be used in repair and emergency work in the field of civil engineering and construction, and can be suitably applied as a cement paste, mortar or concrete.

That is, the present invention includes a super fast hardening cement (A) containing calcium aluminate as an essential component, a polyacrylic acid dispersant (B) having a polyethylene oxide chain, and a polyacrylic acid dispersant (C). The polyacrylic acid-based dispersant (B) having a polyethylene oxide chain is a super-fast-hardening cement composition comprising the following general formula (1);

(Wherein R ¹ is the same or different and represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. N represents an average number of added moles and is a number of 10 to 300). A repeating unit derived from a monomer and the following general formula (2);

(Wherein M represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or an organic amine group) and a copolymer having a repeating unit derived from a monomer represented by It is a super fast-hardening cement composition.
The present invention is also a cement dispersant used to disperse an ultrafast cement containing calcium aluminate as an essential component, wherein the cement dispersant is represented by the following general formula (1);

(Wherein R ¹ is the same or different and represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. N represents an average number of added moles and is a number of 10 to 300). A repeating unit derived from a monomer and the following general formula (2);

(Wherein M represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or an organic amine group), and a copolymer having a repeating unit derived from a monomer; It is also a cement dispersant containing polyacrylic acid and / or a salt thereof.
The present invention is described in detail below.

The present invention relates to a super fast hardness comprising a super fast hardening cement (A) containing calcium aluminate as an essential component, a polyacrylic acid dispersant (B) having a polyethylene oxide chain, and a polyacrylic acid dispersant (C). It is a cement composition.
The super fast-hardening cement composition has calcium aluminate as an essential component, and has a faster curing speed than a general cement composition. The curing speed is JIS R 5201 “Physical properties of cement”. The compressive strength at the age of 3 hours measured according to “Test method” is preferably 20 N / mm ² or more. The upper limit is not particularly limited, but is preferably 60 N / mm ² or less.
As said super-fast-hardening cement (A), calcium aluminate is used as an essential component, and calcium aluminate is a component which improves fast-hardening in a super-hard-hardening cement composition.

As the calcium _{aluminates, C 11 A 7 · CaX 2} , C 3 A, CA, C 2 AS, CA 2, C 3 A 3 · CaSO 4, C 12 A 7, C 6 AF 2 and _C 4 AF (In the formula, C represents CaO. A represents Al ₂ O _3. S represents SiO ₂ (wherein S in CaSO ₄ represents a sulfur atom.) F represents Fe ₂ O. ₃ represents X. X represents a halogen element), and the main component is at least one selected from the group consisting of amorphous calcium aluminate. Among them, more _{preferably, C 11 A 7 · CaF 2} , an amorphous calcium aluminate, more _preferably C ₁₁ A 7 · CaF _2.
As content of the said calcium aluminate, it is preferable that it is 10-30 mass% with respect to 100 mass% of super-fast-hardening cement (A). If the amount is less than 10% by mass, the rapid curing may not be sufficiently exhibited. If the amount exceeds 30% by mass, the pot life may not be sufficiently secured and the workability may not be sufficiently improved.

The polyacrylic acid dispersant (B) having a polyethylene oxide chain is composed of a repeating unit derived from the monomer represented by the general formula (1) (also referred to as a repeating unit (I)) and the general formula (I). 2) Copolymer (polyacrylic acid copolymer having a polyethylene oxide chain or polyacrylic acid copolymer) having a repeating unit derived from the monomer represented by 2) (also referred to as repeating unit (II)) (Also referred to as a polymer). When using a polyacrylic acid copolymer having a polyethylene oxide chain, good fluidity can be obtained with a small addition amount, and fluidity can be maintained without increasing the addition amount of a setting retarder. . Moreover, since the polyacrylic acid-type copolymer which has the said structure is excellent in quick-hardness, when used as a cement dispersing agent, it can be used conveniently as a super-fast-hardening cement composition.

In the above-mentioned super-fast-hardening cement composition, the ratio of the super-fast-hardening cement (A) and the polyacrylic acid dispersant (B) having a polyethylene oxide chain is (B) / (A) = 0.01 / 100-8. 0.0 / 100 is preferred. If it is less than 0.01 / 100, the dispersion effect is insufficient, and if it exceeds 8.0 / 100, the dispersion effect reaches its peak, which may be uneconomical. More preferably, (B) / (A) = 0.2 / 100 to 0.4 / 100.
As a ratio of the super-hard setting cement to the super-hard setting cement composition, super-fast setting cement / super-fast setting cement composition = 10/100 to 80/100 is preferable. If it is less than 10/100, the strength and durability are insufficient, and if it exceeds 80/100, uniform kneading may be difficult.

The polyacrylic acid dispersant (C) is not particularly limited as long as it contains polyacrylic acid and / or a salt thereof (also referred to as polyacrylic acid (salt)).
The polyacrylic acid salt is preferably a salt of a monovalent metal atom, a divalent metal atom, an ammonium group, an organic amine group or the like. The monovalent metal atom is preferably an alkali metal atom such as lithium, sodium or potassium, and the divalent metal atom is preferably an alkaline earth metal atom such as calcium or magnesium. As the organic amine group, an alkanolamine group such as an ethanolamine group, a diethanolamine group, or a triethanolamine group, a triethylamine group, an organic ammonium group, or the like is preferable. Among these, a sodium salt or a calcium salt is preferable. More preferably, it is a sodium salt.

The molecular weight of polyacrylic acid (salt) contained in the polyacrylic acid-based dispersant is preferably 10,000 to 100,000. When the molecular weight is less than 10,000 or exceeds 100,000, the initial fluidity and fluidity retention may not be sufficient. More preferably, it is 20000-80000, More preferably, it is 40000-60000. In the super fast-hardening cement composition of the present invention, the molecular weight of polyacrylic acid (salt) may be appropriately set according to the required performance, but from the viewpoint of initial fluidity and fluidity retention, it is around 50,000. This is a preferred embodiment. In addition, the said molecular weight shows the weight average molecular weight obtained by the measuring method by gel permeation chromatography.

(Weight average molecular weight measurement conditions)
Model: Waters LCM1
Detector: Waters 410 Differential refraction detector analysis software: Waters MILLENNIUM Ver. 2.18
Eluent: An eluent prepared by dissolving 115.6 g of sodium acetate trihydrate in a mixed solution of 10999 g of water and 6001 g of acetonitrile and adjusting the pH to 6.0 with a 30% aqueous sodium hydroxide solution is used.
Eluent flow rate: 0.8ml / min
Column temperature: 35 ° C
Column: Tosoh TSKgel GuardColumnSWXL + G4000SWXL + G3000SWXL + G2000SWXL
Reference material: polyethylene glycol, weight average molecular weight (Mw) 272500, 219300, 85000, 46000, 24000, 12600, 4250, 7100, 1470

As content of the said polyacrylic acid (salt), unless the effect of this invention is impaired, it is not specifically limited to the kind and content. A preferred range is that substantially all of the polyacrylic acid dispersant (C) is polyacrylic acid (salt). In addition to the polyacrylic acid (salt), the components contained in the polyacrylic acid dispersant (C) are not particularly limited to the type and content thereof as long as the effects of the present invention are not impaired.

As for the addition amount of the said polyacrylic-acid type dispersing agent (C), (C) / (A) = 0.05-2.0 mass% is preferable with respect to a super-fast-hardening cement (A). By adding the polyacrylic acid dispersant (C) in such a range, excellent fluidity can be exhibited even at a low temperature, and a sufficient working life is ensured, and super-hardness with good workability. It can be a cement composition. More preferably, it is (C) / (A) = 0.1-1.5 mass%, More preferably, it is 0.2-1.0 mass%.

It is preferable that the super-hard setting cement composition further contains a setting retarder. By including a setting retarder (sometimes simply referred to as a retarder), high dispersion retention performance can be exhibited, and the pot life of the work of the super-hard cement composition can be adjusted.
The setting retarder is not particularly limited as long as it delays the hydration reaction of the ultrafast hard cement used, but is preferably an oxycarboxylic acid compound. The oxycarboxylic acid compound refers to a compound having a hydroxyl group and a carboxyl group or a salt thereof in the molecule. As the oxycarboxylic acid compound, an oxycarboxylic acid having 4 to 10 carbon atoms or a salt thereof is preferable. For example, citric acid, gluconic acid, tartaric acid, glucoheptonic acid, arabonic acid, malic acid, and one or two of these inorganic salts or organic salts such as sodium, potassium, calcium, magnesium, ammonium, triethanolamine, etc. The above is preferable. Among these, it is preferable to use gluconic acid or a salt thereof.

The content of the setting retarder (setting retarder / superfast cement (mass ratio)) is preferably 0.01 to 1.0 with respect to 100% by mass of the ultrafast cement (A). If the setting retarder is less than 0.01, the fluidity retention may not be sufficient, and if it exceeds 1.0, the initial strength development may not be sufficient. More preferably, it is 0.02-0.5, More preferably, it is 0.05-0.4.

The above super-hard setting cement composition can be kneaded and placed at an ambient temperature of 15 ° C. or lower. By kneading and placing at an atmospheric temperature of 15 ° C. or lower, the composition can be suitably used without causing a decrease in strength that occurs in other superfast-hardening cement compositions even in winter when the demand for the superfast-hardening cement composition is high. The ambient temperature for kneading and placing is more preferably 10 ° C. or lower, and further preferably 5 ° C. or lower. As a lower limit, 0 degreeC or more is suitable. In addition, although it is preferable that the super-fast-hardening cement composition of this invention is knead | mixed and set | placed by the atmospheric temperature of 15 degrees C or less, it can be used conveniently also in normal temperature atmospheres, such as 15-45 degreeC.

The present invention is also a cement dispersant used to disperse a super fast hard cement containing calcium aluminate as an essential component, wherein the cement dispersant is a monomer represented by the general formula (1). It is also a cement dispersant containing a copolymer having a repeating unit derived from and a repeating unit derived from the monomer represented by the general formula (2), and polyacrylic acid and / or a salt thereof.

As the copolymer (polyacrylic acid copolymer) contained in the cement dispersant, the repeating unit derived from the monomer represented by the general formula (1) (repeating unit (I)), and the above It has a repeating unit derived from the monomer represented by the general formula (2) (repeating unit (II)), and a monomer that gives the repeating unit (I) and a single unit that gives the repeating unit (II). It can be produced by copolymerizing a monomer component containing a monomer as an essential component. Such a monomer component may further contain a monomer that provides the structural unit (III). In the polyacrylic acid-based copolymer, the copolymerization of the repeating unit (I), the repeating unit (II), and the structural unit (III) to be included as necessary includes random copolymerization, Any of block copolymerization and alternating copolymerization may be used.
Moreover, as said polyacrylic acid (salt), it is the same as that of having demonstrated in the super-fast-hardening cement composition of this invention, The thing mentioned above is suitable for the super-hard-hardening cement which uses calcium aluminate as an essential component.

The polyacrylic acid copolymer and the polyacrylic acid (salt) may both be included in the super-hard setting cement composition. (1) Polyacrylic acid copolymer and polyacrylic acid (salt) (2) A polyacrylic acid dispersant having a polyethylene oxide chain and a polyacrylic acid dispersant added separately, and (3) a polyacrylic acid copolymer. Any of the forms in which a part of the polymer and / or a part of the polyacrylic acid (salt) is used as in the above (1) and (2) may be used. The cement dispersant of the present invention includes an aspect applicable to these usage forms, that is, an aspect in which a polyacrylic acid copolymer and polyacrylic acid (salt) are combined.

The present invention further relates to a cement dispersant used to disperse a super fast-hardening cement containing calcium aluminate as an essential component together with a cement dispersant containing polyacrylic acid and / or a salt thereof. Is a cement containing a copolymer having a repeating unit derived from the monomer represented by the general formula (1) and a repeating unit derived from the monomer represented by the general formula (2). It is also a dispersant.
In the cement dispersant, the polyacrylic acid copolymer is the same as described in the cement dispersant used to disperse the above ultra-hard cement, and includes polyacrylic acid (salt) and calcium aluminum. As the super-hard setting cement containing nates as essential components, those described above are suitable.

In the general formula (1), ^{R 1} may be the same or different and each represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms. The alkyl group having 1 to 5 carbon atoms may be linear or branched. For example, a hydrogen atom, a methyl group, or an ethyl group is preferable, and among these, a hydrogen atom is preferable. The average addition mole number n of an oxyethylene group is a number of 10 to 300, preferably 15 to 200, and more preferably 25 to 100.

In the general formula (2), M represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group, or an organic amine group. The monovalent metal atom is preferably an alkali metal atom such as lithium, sodium or potassium, and the divalent metal atom is preferably an alkaline earth metal atom such as calcium or magnesium. As the organic amine group, an alkanolamine group such as an ethanolamine group, a diethanolamine group, or a triethanolamine group, a triethylamine group, an organic ammonium group, or the like is preferable. Among these, sodium and calcium are preferable. That is, the monomer represented by the general formula (2) is preferably a sodium salt or a calcium salt.

In the polyacrylic acid-based copolymer, the ratio of the repeating unit (I), the repeating unit (II) and the other structural unit (III) is a mass ratio of the repeating unit (I) / repeating unit (II) / others. The structural unit (III) is preferably 98 to 2/2 to 98/0 to 50. More preferably, it is 95-50 / 5-5-50 / 0-50, More preferably, it is 95-70 / 5-30 / 0-50. However, the total of the repeating unit (I), the repeating unit (II) and the structural unit (III) is 100% by mass.

As a monomer that gives the structural unit (I) that can be used in the present invention, a compound obtained by adding a 10-300 molar polymer of ethylene oxide to 3 -methyl- 3 -buten-1-ol, 3-methyl- 3 A compound in which 10-300 moles of ethylene oxide was added to -buten-1-ol, and then a hydroxyl group at the terminal was substituted with an alkyl group. Polyethylene glycol monoalkyl ether was added to 3-methyl- 3 -buten-1-ol. The reacted compound is mentioned. Examples of the monomer that provides the structural unit (II) that can be used in the present invention include acrylic acid.

The monomer that provides the structural unit (III) that can be used in the present invention may be any monomer that can be copolymerized with at least one of the other monomers, and the following are preferred.
Half esters and diesters of unsaturated dicarboxylic acids such as maleic acid, fumaric acid, itaconic acid and citraconic acid and alcohols having 1 to 4 carbon atoms; half of the above unsaturated dicarboxylic acids and amines having 1 to 30 carbon atoms Amides and diamides: Half esters and diesters of alkyl (poly) alkylene glycols obtained by adding 1 to 500 moles of alkylene oxides having 2 to 18 carbon atoms to the above alcohols and amines; and the above unsaturated dicarboxylic acids; Ester and diester of a glycol having 2 to 18 carbon atoms or a polyalkylene glycol having 2 to 300 addition moles of these glycols.

Half amides of maleamic acid and glycols having 2 to 18 carbon atoms or polyalkylene glycols having 2 to 300 addition moles of these glycols; triethylene glycol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate (Poly) alkylene glycol di (meth) acrylates such as polypropylene glycol di (meth) acrylate and (poly) ethylene glycol (poly) propylene glycol di (meth) acrylate; hexanediol di (meth) acrylate, trimethylolpropane tri Bifunctional (meth) acrylates such as (meth) acrylate and trimethylolpropane di (meth) acrylate; (poly) alkylene groups such as triethylene glycol dimaleate and polyethylene glycol dimaleate Call dimaleate class.

Vinyl sulfonate, (meth) allyl sulfonate, 2- (meth) acryloxyethyl sulfonate, 3- (meth) acryloxypropyl sulfonate, 3- (meth) acryloxy-2-hydroxypropyl sulfonate, 3- (meth) acryloxy-2 -Hydroxypropylsulfophenyl ether, 3- (meth) acryloxy-2-hydroxypropyloxysulfobenzoate, 4- (meth) acryloxybutylsulfonate, (meth) acrylamidomethylsulfonic acid, (meth) acrylamidoethylsulfonic acid, 2- Unsaturated sulfonic acids such as methylpropane sulfonic acid (meth) acrylamide and styrene sulfonic acid, and monovalent metal salts, divalent metal salts, ammonium salts and organic amine salts thereof; acrylic acid, methacrylic acid, croto Acid and unsaturated monocarboxylic acid-based compounds, and their metal salts, ammonium salts, amine salts.

Unsaturated monocarboxylic acids such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, glycidyl (meth) acrylate, methyl crotonate, ethyl crotonate, propyl crotonate and the like and those having 1 to 4 carbon atoms Esters with alcohols; Amides of unsaturated monocarboxylic acids and amines having 1 to 30 carbon atoms such as methyl (meth) acrylamide; Vinyl aromas such as styrene, α-methylstyrene, vinyltoluene, p-methylstyrene Alkanediol mono (meth) acrylates such as 1,4-butanediol mono (meth) acrylate, 1,5-pentanediol mono (meth) acrylate, 1,6-hexanediol mono (meth) acrylate; butadiene , Isoprene, 2-methyl-1, -Dienes such as butadiene and 2-chloro-1,3-butadiene; Unsaturation such as (meth) acrylamide, (meth) acrylalkylamide, N-methylol (meth) acrylamide, N, N-dimethyl (meth) acrylamide, etc. Amides; unsaturated cyanides such as (meth) acrylonitrile and α-chloroacrylonitrile.

Unsaturated esters such as vinyl acetate and vinyl propionate; aminoethyl (meth) acrylate, methylaminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, (meth ) Unsaturated amines such as dibutylaminoethyl acrylate and vinyl pyridine; divinyl aromatics such as divinylbenzene; cyanurates such as triallyl cyanurate; allyls such as (meth) allyl alcohol and glycidyl (meth) allyl ether ; Unsaturated amino compounds such as dimethylaminoethyl (meth) acrylate; methoxypolyethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, methoxypolyethylene glycol mono (meth) allyl ether, polyethylene glycol Mono (meth) vinyl or allyl ethers such as allyl ether.
Polydimethylsiloxanepropylaminomaleamic acid, polydimethylsiloxaneaminopropylaminomaleamic acid, polydimethylsiloxane-bis- (propylaminomaleamic acid), polydimethylsiloxane-bis- (dipropylaminomaleamic acid), polydimethyl Siloxane- (1-propyl-3-acrylate), polydimethylsiloxane- (1-propyl-3-methacrylate), polydimethylsiloxane-bis- (1-propyl-3-acrylate), polydimethylsiloxane-bis- (1 Siloxane derivatives such as (propyl-3-methacrylate); unsaturated phosphate esters such as 2-acryloyloxyethyl phosphate and 2-methacryloyloxyethyl phosphate.

Polyalkylene polyamines such as diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, dipropylenetriamine, tripropylenetetramine, tetrapropylenepentamine, and malonic acid, succinic acid, fumaric acid, maleic acid, azelaic acid, sebacic acid Or a condensate of a dibasic acid such as an esterified product of these with an alcohol having 1 to 20 carbon atoms or an ester of a dibasic acid and an alcohol having 1 to 20 carbon atoms with (meth) acrylic acid or (meth) A specific amount of alkylene oxide to a polyamide polyamine obtained by condensing an esterified product of acrylic acid and an alcohol having 1 to 20 carbon atoms, an unsaturated epoxy compound such as glycidyl (meth) acrylate and allyl glycidyl ether at a specific ratio. Added compounds; Esterified products of (meth) acrylic acid or (meth) acrylic acid and alcohols having 1 to 20 carbon atoms with compounds obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to active hydrogen of polyalkyleneimines such as reethyleneimine and polypropyleneimine Or a cationic monomer having a nitrogen atom such as a condensate with an unsaturated epoxidized product such as glycidyl (meth) acrylate and allyl glycidyl ether.

In order to obtain the polyacrylic acid copolymer, the monomer component may be polymerized using a polymerization initiator. The polymerization can be performed by a method such as polymerization in a solvent or bulk polymerization. Polymerization in a solvent can be carried out either batchwise or continuously. The solvent used here is water; lower alcohols such as methyl alcohol, ethyl alcohol, 2-propanol; benzene, toluene, xylene, cyclohexane, One or more of aromatic or aliphatic hydrocarbons such as n-hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone are preferred. From the solubility of the raw material monomer and the resulting polyacrylic acid copolymer and the convenience when using the polyacrylic acid copolymer, it is selected from the group consisting of water and lower alcohols having 1 to 4 carbon atoms. It is preferable to use at least one selected from the above. In that case, among lower alcohols having 1 to 4 carbon atoms, methyl alcohol, ethyl alcohol, 2-propanol and the like are particularly effective.

When the polymerization is carried out in an aqueous medium to obtain the polyacrylic acid copolymer, a water-soluble polymerization initiator such as ammonium or alkali metal persulfate or hydrogen peroxide may be used as the polymerization initiator. preferable. In this case, an accelerator such as sodium bisulfite, Mole salt, ascorbic acid (salt), Rongalite and the like can be used in combination. For polymerization using a lower alcohol, aromatic hydrocarbon, aliphatic hydrocarbon, ester compound or ketone compound as a solvent, peroxides such as benzoyl peroxide and lauroyl peroxide; hydroperoxides such as cumene hydroperoxide; azo It is preferable to use an azo compound such as bisisobutyronitrile as a polymerization initiator. In this case, an accelerator such as an amine compound can be used in combination. Furthermore, when a water-lower alcohol mixed solvent is used, it can be appropriately selected from the above-mentioned various polymerization initiators or combinations of polymerization initiators and accelerators. Although superposition | polymerization temperature is suitably determined with the solvent and polymerization initiator to be used, it is 0-120 degreeC normally, and 30 degreeC or more is preferable. More preferably, it is 50 ° C. or higher. Moreover, 100 degrees C or less is preferable. More preferably, it is 95 degrees C or less.

When bulk polymerization is carried out, usually a peroxide such as benzoyl peroxide or lauroyl peroxide; a hydroperoxide such as cumene hydroperoxide; an azo compound such as azobisisobutyronitrile is used as the polymerization initiator; Performed at ° C.

Furthermore, hypophosphorous acid (salt) and a thiol chain transfer agent can be used in combination for adjusting the molecular weight of the resulting polyacrylic acid copolymer. The thiol chain transfer agent used in this case has a general formula HS-R ³⁰ -Eg (wherein R ³⁰ represents an alkyl group having 1 to 2 carbon atoms. E represents —OH, —COOM, — COOR ³¹ or SO ₃ M group, M represents a hydrogen atom, monovalent metal, divalent metal, ammonium group or organic amine group, R ³¹ represents an alkyl group having 1 to 30 carbon atoms, g Represents an integer of 1-2. Octyl is preferred. Moreover, you may use the thiol compound which has a C3-C3 or more hydrocarbon group which does not have functional groups, such as a hydroxyl group and a carboxyl group, as a chain transfer agent. Butanethiol, octanethiol, decanethiol, dodecanethiol, hexadecanethiol, cyclohexyl mercaptan, thiophenol are suitable as such thiol compounds. In addition, halides such as carbon tetrachloride, carbon tetrabromide, methylene chloride, bromoform, and bromotrichloroethane; unsaturated hydrocarbon compounds such as α-methylstyrene dimer, α-terpinene, γ-terpinene, and dipentene as chain transfer agents. It may be used. These 1 type (s) or 2 or more types can be used. In order to adjust the molecular weight of the polyacrylic acid copolymer, it is also effective to use a monomer having a high chain mobility such as (meth) allylsulfonic acid (salt) as the monomer (e). is there.

The polyacrylic acid-based copolymer can be used as it is, but in the case where the solubility in water is insufficient, the solubility in water is improved and the aqueous medium liquid does not contain an organic solvent. For handling, monovalent and divalent metal hydroxides, inorganic substances such as chlorides and carbon salts; ammonia; organic amines (preferably monohydric metal hydroxides such as sodium hydroxide and potassium hydroxide) It is preferable to use it as a polymer salt obtained by neutralization with an alkaline substance.

The weight average molecular weight of the polyacrylic acid copolymer is suitably 5000 to 1000000 in terms of polyethylene glycol by gel permeation chromatography (hereinafter referred to as “GPC”), but is preferably 500000 or less. More preferably, it is 10,000 or more. More preferably, it is 300,000 or less. If the weight average molecular weight is less than 5,000, the material separation reduction performance may be lowered, and if it exceeds 1,000,000, the dispersion performance may be lowered.

(Weight average molecular weight measurement conditions)
Model: Waters LCM1
Detector: Waters 410 Differential refraction detector analysis software: Waters MILLENNIUM Ver. 2.18
Eluent: An eluent prepared by dissolving 115.6 g of sodium acetate trihydrate in a mixed solution of 10999 g of water and 6001 g of acetonitrile and adjusting the pH to 6.0 with a 30% aqueous sodium hydroxide solution is used.
Eluent flow rate: 0.8ml / min
Column temperature: 35 ° C
Column: Tosoh TSKgel GuardColumnSWXL + G4000SWXL + G3000SWXL + G2000SWXL
Reference material: polyethylene glycol, weight average molecular weight (Mw) 272500, 219300, 85000, 46000, 24000, 12600, 4250, 7100, 1470

The blending ratio of the cement dispersant (the total of the polyacrylic acid copolymer and polyacrylic acid (salt)) in the ultrafast cement composition of the present invention (cement dispersant / superfast cement composition) is ultrafast. 0.01 mass% or more is preferable with respect to 100 mass% of cement compositions, and 5.0 mass% or less is preferable. If the above blending ratio is less than 0.01% by mass, the performance may be insufficient, and even if a large amount exceeding 5.0% by mass is used, the effect is practically peaked and is economical. May be disadvantageous. More preferably, it is 0.02 mass% or more, More preferably, it is 0.05 mass% or more. Moreover, it is 2.0 mass% or less more preferably, More preferably, it is 1.0 mass% or less, What is necessary is just to add the quantity used as such a ratio. By this addition, various preferable effects such as reduction in unit water amount, increase in strength, and improvement in durability are brought about.

Next, the super fast hardening cement (A) in the super fast hardening cement composition of the present invention will be described. The super fast-hardening cement in the present invention is composed of a clinker mineral containing calcium aluminate and a sulfate. The clinker mineral includes C ₃ S and C ₂ S in addition to the aforementioned calcium aluminates. Examples of sulfates include alkali metal sulfates such as sodium sulfate (sodium sulfate) and potassium sulfate, alkaline earth metal sulfates such as magnesium sulfate and gypsum (calcium sulfate), and aluminum sulfate. Or the combined use of gypsum and mirabilite. Examples of the gypsum include anhydrous gypsum, hemihydrate gypsum, dihydrate gypsum, or a mixture thereof. Moreover, slaked lime is mentioned as a material which can be mix | blended as needed. The slaked lime is added for strength enhancement.
It is preferable that the ratios of clinker mineral, sulfate, and slaked lime added as necessary in the ultrafast cement are 70 to 90 mass%, 10 to 30 mass%, and 0 to 1 mass%, respectively. Moreover, the super-fast-hardening cement formed by mixing the quick-hardening component of this invention with cements, such as the following Portland cement, may be sufficient.
As the cement component of the ultrafast cement composition, fine powder such as blast furnace slag, fly ash, cinder ash, clinker ash, husk ash, silica fume, silica powder, limestone powder, or gypsum may be added. In addition to ultra-hard cement, Portland cement (ordinary, early strength, ultra-fast strength, moderate heat, sulfate-resistant and low alkali type of each), various mixed cements (blast furnace cement, silica cement, fly ash cement), White Portland cement, alumina cement, grout cement, oil well cement, low heat generation cement (low heat generation blast furnace cement, fly ash mixed low heat generation blast furnace cement, high content of belite), super high strength cement, cement-based solidified material, You may use 1 type (s) or 2 or more types, such as an eco-cement (a cement manufactured using one or more types of municipal waste incineration ash and sewage sludge incineration ash).

The super-fast-hardening cement composition of the present invention contains super-fast-hardening cement (A), a polyacrylic acid-based dispersant (B) having a polyethylene oxide chain, and polyacrylic acid-based dispersant (C) as essential components. Although it may contain a setting retarder, it may further contain aggregates such as fine aggregate and coarse aggregate, and other components.
As the fine aggregate, sand is suitable, and as coarse aggregate, in addition to river gravel, crushed stone, granulated slag, recycled aggregate, etc., siliceous, clayey, zircon, high alumina, silicon carbide Refractory aggregates such as qualitative, graphite, chromic, chromic and magnesia can be used. These may be used alone or in combination of two or more.

In the superfast cement composition of the present invention, the unit water amount per 1 m ³ of the superfast cement composition (water / superfast cement composition), the amount of cement used (superfast cement and other cement components as required), The amount of coarse aggregate and retarder / ultra-fast hardened cement composition includes a unit water amount of 100 to 185 kg / m ³ , a used cement amount of 250 to 800 kg / m ³ , a unit coarse aggregate amount of 500 to 1500 kg / m ³ , and a water / super speed. It is preferable that hard cement composition ratio (mass ratio) = 0.1 to 0.7, retarder / super fast hard cement composition (mass ratio) = 5 × 10 ^{−6 to} 5 × 10 ⁻³ . The unit water amount is more preferably 120 kg / m ³ or more, and more preferably 175 kg / m ³ or less. The amount of super fast hardened cement used is more preferably 270 kg / m ³ or more, and more preferably 800 kg / m ³ or less. The unit coarse aggregate amount is more preferably 600 kg / m ³ or more, further preferably 800 kg / m ³ or more, more preferably 1300 kg / m ³ or less, and still more preferably 1200 kg / m ³ or less. The water / ultrafast hard cement composition ratio (mass ratio) is more preferably 0.15 or more, and still more preferably 0.2 or more. Moreover, 0.65 or less is more preferable and 0.5 or less is still more preferable. Retarder / ultrarapid hardening cement composition (mass ratio), more preferably ^{5 × 10 -5 ~2 × 10 -3} , 1 × 10 -4 ~1.2 × 10 -3 is more preferable. The super fast-hardening cement composition of the present invention can be widely used from poor blending to rich blending, and is effective for both high-strength concrete with a large amount of unit cement and poor blended concrete with a unit cement amount of 300 kg / m ³ or less. is there.

In addition to the above, the super-fast-hardening cement composition of the present invention is not limited to the above-mentioned cement dispersants, AE agents, antifoaming agents, cement wetting agents, and swelling agents. Other concrete such as waterproofing agent, quick setting agent, thickener, flocculant, drying shrinkage reducing agent, strength enhancer, curing accelerator, shrinkage reducing agent, separation reducing agent, neutralization inhibitor, rust inhibitor Admixtures and other water-soluble polymer compounds may be used in combination.

Specific examples of the above-mentioned cement dispersants other than polyacrylic acid include polyalkylaryl sulfonates such as naphthalene sulfonic acid formaldehyde condensate, methyl naphthalene sulfonic acid formaldehyde condensate, anthracene sulfonic acid formaldehyde condensate; melamine sulfonic acid Melamine formalin sulfonates such as formaldehyde condensates; aromatic amino sulfonates such as aminoaryl sulfonic acid-phenol-formaldehyde condensates; lignin sulfonates such as lignin sulfonate and modified lignin sulfonate And various sulfonic acid cement dispersants such as polystyrene sulfonate salt.

In the present invention, it is also preferable to further contain an AE agent when high-quality air is introduced into the ultrafast-hardening cement composition to improve freeze-thaw resistance. In this case, when the kneading time is extended at the time of production of the ultrafast cement composition, that is, even when the kneading is continued for a long time during the transportation of the ultrafast cement composition, the above-mentioned ultrafast cement composition has an entrained air amount. Can be kept stable, and the cured product can be excellent in freeze-thaw resistance, strength, and durability.

In the super fast-hardening cement composition of the present invention, an alkyl ether type anionic surfactant type, a modified rosin acid compound type anionic surfactant type, an alkyl sulfonic acid compound type anionic surfactant type, a high alkyl carboxyl type Various AE agents such as acid salt type anionic surfactant type, modified alkylcarboxylic acid compound type anionic surfactant type, Vinsol (trade name, manufactured by Yamaso Chemical Co., Ltd.), or Micro-Air (Micro-Air, You may use together a brand name, the Master Builders company etc.).

Specific examples of the AE agent include sodium hydroxystearate, lauryl sulfate, ABS (alkyl benzene sulfonic acid), LAS (linear alkyl benzene sulfonic acid), alkane sulfonate, polyoxyethylene alkyl (phenyl) ether, polyoxyethylene alkyl ( Phenyl) ether sulfate or a salt thereof, polyoxyethylene alkyl (phenyl) ether phosphate or a salt thereof, protein material, alkenylsulfosuccinic acid, α-olefin sulfonate, and the like.

Specific examples of the antifoaming agent include polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene Polyoxyalkylene alkyl ethers such as polyoxypropylene 2-ethylhexyl ether and oxyethyleneoxypropylene adducts of higher alcohols having 12 to 14 carbon atoms; polyoxyalkylene alkyl ethers such as polyoxypropylene phenyl ether and polyoxyethylene nonylphenyl ether Alkylene (alkyl) aryl ethers; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5-dimethyl-3-hexyne-2,5-diol, 3-methyl- 1 Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohol such as butyn-3-ol; (poly) oxyalkylene fatty acid esters such as diethylene glycol oleate, diethylene glycol laurate, ethylene glycol distearate; polyoxyethylene Polyoxyalkylene sorbitan fatty acid esters such as sorbitan monolaurate and polyoxyethylene sorbitan trioleate; polyoxyalkylene alkyl (aryl) ether sulfate such as sodium polyoxypropylene methyl ether sulfate and sodium polyoxyethylene dodecylphenyl ether sulfate Ester salts; polyoxyalkylenes such as polyoxyethylene stearyl phosphates Kill phosphoric acid esters; polyoxypropylene polyoxyethylene laurylamine (1-20 mol addition of propylene oxide, 1-20 mol addition product of ethylene oxide, etc.), cured beef tallow amine added with alkylene oxide (1-20 mol addition of propylene oxide, Polyoxyalkylene alkylamines such as ethylene oxide 1-20 mol adducts, etc .; polyoxyalkylene amides, etc. These antifoaming agents may use only 1 type and may use 2 or more types together. The antifoaming agent may be added before polymerization is started, during polymerization, or after polymerization. Moreover, it is preferable that an addition rate shall be 0.0001-10 mass% with respect to the total mass of the polymer for super-fast-hardening cement compositions.

Specific examples of the antifoaming agent other than the oxyalkylene type include mineral oil type antifoaming agents such as coconut oil and liquid paraffin; fat and oil type antifoaming agents such as animal and vegetable oils, sesame oil, castor oil, and adducts thereof with these alkylene oxides; oleic acid , Stearic acid, fatty acid-based antifoaming agents such as these alkylene oxide adducts; fatty acid ester-based antifoaming agents such as glycerin monoricinoleate, alkenyl succinic acid derivatives, sorbitol monolacrate, sorbitol trioleate, natural wax; octyl alcohol , Hexadecyl alcohol, acetylene alcohol, glycols, etc .; defoamers such as acrylate polyamines; phosphate defoamers such as tributyl phosphate, sodium octyl phosphate; aluminum stearate , Calcium oleate, etc. Genus soap antifoaming agents; dimethylsilicone oils, silicone pastes, silicone emulsions, organic modified polysiloxanes (polyorganosiloxanes dimethylpolysiloxane), silicone-based defoaming agent such as fluorosilicone oil, and the like.

Specific examples of the curing accelerator include soluble calcium salts such as calcium chloride, calcium nitrite, calcium nitrate, calcium bromide and calcium iodide; chlorides such as iron chloride and magnesium chloride; sulfates; potassium hydroxide; Sodium hydroxide; carbonate; thiosulfate; formate such as formic acid and calcium formate; alkanolamine; alumina cement; calcium aluminate silicate.

Specific examples of the water-soluble polymer compound include nonionic cellulose ethers such as methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, carboxymethylcellulose, carboxyethylcellulose, hydroxypropylcellulose; methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose. Hydrophobic substituents in which part or all of the hydroxyl groups of the alkylated or hydroxyalkylated derivatives of polysaccharides have a hydrocarbon chain having 8 to 40 carbon atoms as a partial structure, and sulfonic acid groups or the like Derivatives of polysaccharides substituted with ionic hydrophilic substituents having a partial structure thereof: yeast glucan, xanthan gum, β-1,3 glucans (straight and branched chain) For example, polysaccharides produced by biofermentation such as curdlan, paramylon, pachyman, scleroglucan, laminaran); polyacrylamide; polyvinyl alcohol; starch; starch phosphate ester; sodium alginate Gelatin, acrylic acid copolymer having an amino group in the molecule, and a quaternary compound thereof.

The present invention is also a method for producing an ultrafast cement composition, which is a method for producing an ultrafast cement composition including a step of kneading and placing at an ambient temperature of 15 ° C. or less. In the present invention, by kneading and placing under a low temperature atmosphere such as a step of kneading and placing at an ambient temperature of 15 ° C. or less, excellent fast hardening can be achieved even in the winter when demand for an ultrafast cement composition is high. And sufficient pot life can be secured. In the manufacturing method of this invention, what is necessary is just to include the said process, The addition method, order, etc. of each manufacturing raw material are not specifically limited.
The above-mentioned super fast-hardening cement composition can be suitably manufactured by a manufacturing method including the above steps. Moreover, the preferable form etc. in the manufacturing method of this invention are the same as having demonstrated in the super-fast-hardening cement composition of this invention.

The above ultra-fast-hardening cement composition can improve workability while maintaining fast-hardening, and can fully demonstrate the effects of the present invention even in a low-temperature atmosphere. And can be suitably used for cement paste, mortar or concrete.

The ultrafast cement composition and the dispersant for an ultrafast cement composition of the present invention have the above-described configuration, and not only have excellent rapid curing, fluidity, initial strength development, etc. in a low temperature atmosphere, but also fluid retention. Since it is excellent in property, it can be suitably used in various repairs, reinforcements, emergency constructions, concrete product manufacturing, and the like of building outer wall materials and building structures.

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. Unless otherwise specified, “part” means “part by weight” and “%” means “mass%”.

The materials and performance evaluation methods used in the examples are shown below.
[Materials used]
(1) Super fast setting cement jet cement (Sumitomo Osaka Cement Co., Ltd.)
(2) Cement dispersant Polyacrylic acid dispersant with polyethylene oxide chain Naphthalene dispersant: Formalin condensate of naphthalene sulfonate

Production method of polyacrylic acid type dispersant having polyethylene oxide chain In a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introducing tube and a reflux condenser, water 76.91 g, 3-methyl-3-butene 149.28 g of an unsaturated polyalkylene glycol ether in which 50 mol of ethylene oxide was added to -1-ol on average was charged, and the reaction vessel was purged with nitrogen under stirring and heated to 60 ° C. in a nitrogen atmosphere. When the internal temperature was stabilized at 60 ° C., an aqueous hydrogen peroxide solution containing 0.23 g of hydrogen peroxide and 11.01 g of water was added. Next, 20.17 g of acrylic acid was added dropwise over 3 hours, and an aqueous solution prepared by dissolving 0.3 g of L-ascorbic acid and 0.79 g of 3-mercaptopropionic acid in 40.74 g of water was added dropwise over 3.5 hours. Thereafter, the temperature was continuously maintained at 60 ° C. for 1 hour to complete the polymerization reaction. After completion of the polymerization, the mixture was neutralized with sodium hydroxide and diluted with water to adjust the concentration of the polymerization component to 40% by mass. It was 37000 when the weight average molecular weight of the obtained polyacrylic acid-type copolymer with a polyethylene oxide chain was calculated | required on condition of the following.

Weight average molecular weight measurement conditions Model: Waters LCM1
Detector: Waters 410 Differential refraction detector analysis software: Waters Millenium Ver. 2.18
Eluent: Dissolve 115.6 g of sodium acetate trihydrate in a mixture of 10999 g of water and 6001 g of acetonitrile, and use an eluent adjusted to pH 6 with 30% sodium hydroxide.
Eluent flow rate: 0.8ml / min
Column temperature: 35 ° C
Column: Tosoh TSKgel GuardColumnSWXL + G4000SWXL + G3000SWXL + G2000SWXL
Reference material: polyethylene glycol, weight average molecular weight (Mw) 272500, 219300, 85000, 46000, 24000, 12600, 4250, 7100, 1470

(3) Polyacrylic acid-based dispersant sodium polyacrylate (Molecular weight 50000, manufactured by Toagosei Co., Ltd.)
(4) Setting retarder jet setter (set retarder for jet cement manufactured by Sumitomo Osaka Cement Co., Ltd.)
(5) Sand No. 6 silica sand (Miku Shipping Co., Ltd.)
(6) Test temperature 5 ° C

[Performance evaluation test]
The performance evaluation test of the cement composition was performed in a thermostatic chamber at 5 ° C. as follows.
In the composition shown in Table 1, the materials were mixed for 3 minutes by a Hobart mixer, and the flow value was measured for the obtained mortar as an evaluation of fluidity. As evaluation of pot life, the mortar was allowed to stand for a predetermined time and the flow value was measured to evaluate the change in flow value over time. As an evaluation of the initial strength development, the compressive strength of the mortar at an age of 3 hours was measured. The flow value and compressive strength were measured according to JIS R 5201 “Cement physical test method”.

Example 1 and Comparative Examples 1-3
[Composition of super-hard setting cement composition]
1000 g of jet cement and 1200 g of No. 6 silica sand were kneaded with 380 g of kneaded water to which a dispersant was added to obtain a super fast hard mortar.
Table 1 shows the type and amount of cement dispersant used in Examples and Comparative Examples, the amount of setting retarder added, and the measurement results. In Table 1, the addition amount (C ×%) of the dispersant, the polyacrylic acid-based dispersant, and the setting retarder represents mass% with respect to the cement.

[Explanation of performance evaluation test results]
As shown in Table 1, in the super fast-hardening cement composition of the present invention in which a polyacrylic acid-based dispersant having a polyethylene oxide chain and a polyacrylic acid-based dispersant are used in combination, compared to the case of using a naphthalene-based dispersant. Initial fluidity was obtained with a small amount of dispersant added. Moreover, compared with the case where the polyacrylic acid type | system | group dispersing agent with a polyethylene oxide chain was used alone, the super-hard cement composition which was remarkably excellent in fluidity retention was able to be obtained.

Claims (9)

Super fast hardening cement (A) having calcium aluminate as an essential component, polyacrylic acid dispersant (B) having a polyethylene oxide chain, and polyacrylic acid having a molecular weight of 10,000 to 100,000 and / or a salt thereof. A super-fast-hardening cement composition comprising:
The ratio of the super-hard cement (A) and the polyacrylic acid dispersant (B) having a polyethylene oxide chain is (B) / (A) = 0.01 / 100 to 8.0 / 100,
The addition amount of the polyacrylic acid and / or salt thereof is 0.05 to 2.0% by mass with respect to the ultrafast cement (A),
The polyacrylic acid dispersant (B) having a polyethylene oxide chain is:
The following general formula (1);

(Wherein R ¹ is the same or different and represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. N represents an average number of added moles and is a number of 10 to 300). Repeating units derived from monomers;
The following general formula (2);

(Wherein M represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or an organic amine group) and a copolymer having a repeating unit derived from a monomer represented by A super-hard-hardening cement composition, characterized in that Calcium aluminates that are essential components of the super-hard cement are C ₁₁ A ₇ · CaX ₂ , C ₃ A, CA, C ₂ AS, CA ₂ , C ₃ A ₃ · CaSO ₄ , C ₁₂ A ₇ , C ₆ AF ₂ and C ₄ AF (wherein C represents CaO. A represents Al ₂ O _3. S represents SiO ₂ (wherein S in CaSO ₄ represents a sulfur atom). 2. F represents Fe ₂ O ₃ , X represents a halogen element, and at least one selected from the group consisting of amorphous calcium aluminate as a main component. The super-hard setting cement composition as described. The super-fast-hardening cement composition according to claim 1 or 2 , further comprising a setting retarder. The super fast-hardening cement composition according to claim 3 , wherein the setting retarder is an oxycarboxylic acid compound. The super-fast-hardening cement composition according to any one of claims 1 to 4 , wherein the super-hard-hardening cement composition is kneaded and placed at an ambient temperature of 15 ° C or lower. The super fast-hardening cement composition according to any one of claims 1 to 5, wherein the copolymer has a weight average molecular weight of 5,000 to 1,000,000. It is a manufacturing method of the super-hard-hardening cement composition in any one of Claims 1-6,
The manufacturing method includes a step of kneading and placing at an atmospheric temperature of 15 ° C. or less, and a method for manufacturing an ultrafast hardened cement composition. A cement dispersant used to disperse super fast hard cement containing calcium aluminate as an essential component,
The cement dispersant is
The following general formula (1);

(Wherein R ¹ is the same or different and represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. N represents an average number of added moles and is a number of 10 to 300). Repeating units derived from monomers;
The following general formula (2);

(Wherein M represents a hydrogen atom, a monovalent metal atom, a divalent metal atom, an ammonium group or an organic amine group), and a copolymer having a repeating unit derived from a monomer;
All SANYO molecular weight comprising a polyacrylic acid and / or its salt 10,000 to 100,000,
The cement dispersant is used in such a ratio that the blending ratio of the ultrafast cement and the copolymer is (copolymer) / (superfast cement) = 0.01 / 100 to 8.0 / 100 <br> A cement dispersant characterized by the above. The cement dispersant according to claim 8, wherein the copolymer has a weight average molecular weight of 5,000 to 1,000,000.