JP2005118684A - Dispersant - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dispersant capable of easily dispersing an insoluble material into a liquid material in a liquid medium and to provide a cement admixture which can enhance the dispersibility of an inorganic material into an aqueous medium, can be used as a pigment dispersant and a cement dispersant and, in particular contributes to the reduction of water and higher fluidity of a cement composition. <P>SOLUTION: A structural group (a) originating from vinyl ether, a carboxy-structural group (b) and a nitrogen containing structural group (c) are essential for the dispersant. A polymer (A) having these structural groups at a predetermined ratio enhances the dispersibility of the inorganic material into the aqueous medium, and in particular when applying to the cement composition, enables water saving and is excellent in effect on enhancing the fluidity. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a dispersant. More specifically, the present invention is a dispersant that makes it possible to easily disperse a substance that is insoluble in a liquid substance in a liquid medium, and to improve the dispersibility of an inorganic substance in an aqueous medium. It is useful as a pigment dispersant and a cement dispersant, and is particularly useful as a cement admixture because it can provide a cement composition excellent in cement dispersibility and excellent in fluidity even with a small amount of aqueous medium. .

  Cement compositions are widely used in applications such as building outer wall materials and building structures because they give a hardened cement product with excellent strength and durability. Examples of such a cement composition include cement paste in which water is added to cement, mortar in which sand that is fine aggregate is mixed, concrete in which pebbles that are coarse aggregate are further mixed, etc. Cement admixtures have been added to enhance air entrainment and fluidity, but in recent years, their importance has been recognized and technological innovation has been actively conducted.

  The mission of the cement admixture is to maintain sufficient fluidity and workability even if the cement composition is reduced in water, ensuring its fluidity and workability, and at the same time realizing durability and strength improvement due to water reduction, and stable over time. There exists a place which acquires dispersibility and obtains a favorable cement composition. In the concrete industry in recent years, there is a strong demand for concrete that achieves such performance. To achieve this, reduction of unit water volume and prevention of fluidity deterioration are important issues.

  Among various cement admixtures, in particular, polycarboxylic acid-based cement dispersants are advantageous in that they exhibit high dispersion performance compared to other cement dispersants such as naphthalene, and as such cement dispersants, A cement dispersant containing a copolymer composed of a specific unsaturated polyalkylene glycol ether monomer and a maleic monomer has been proposed (for example, see Patent Document 1).

  However, these polycarboxylic acid-based cement dispersants have not yet completely eliminated the deterioration in dispersion performance over time, and in the high water reduction rate area required for high-strength concrete, Problems such as reduced workability of concrete compositions have arisen. That is, in the high water reduction rate region, the fluidity of the concrete is lowered, the viscosity is increased particularly under a high shear, and the pump load during pumping is extremely large, causing a negative effect on pumping. . In particular, when the temperature is 15 ° C. or lower in winter, the temperature of the concrete is reduced in the same way as the temperature, the viscosity of the concrete is increased, the workability is significantly reduced, and the initial dispersion of the cement dispersant is increased. As a result, there is a problem that the required amount of addition increases or the kneading takes a long time to reduce the productivity. Specifically, cement compositions such as cement paste, mortar, and concrete are used in fields such as civil engineering, construction, and secondary concrete products, so they are used in large quantities and produce kneading time during production. It has a huge impact on sex. If initial dispersibility is low and the time required for kneading takes a long time, not only will the number of daily productions be reduced, but the burden on the mixer will also increase and the amount of kneading per batch will need to be reduced. The amount is reduced, and problems such as wear of the mixer occur.

  As a cement admixture exhibiting high dispersibility and slump loss prevention properties in a high water reduction rate region and having excellent viscosity reducing properties, the present inventors have developed specific unsaturated polyalkylene glycol ether monomers and maleic compounds. A cement admixture based on a copolymer derived by using an acid monomer in a specific ratio has been proposed (see Patent Document 2), but there is still room for improvement.

JP-A-57-118058 JP 2003-95722 A

  The present invention has been made in view of the above-described present situation, and provides a dispersant that can easily disperse a substance insoluble in a liquid substance in a liquid medium, and into an aqueous medium of an inorganic substance. It is an object to provide a cement admixture that is useful as a pigment dispersant and a cement dispersant, and that contributes to water reduction and high fluidization of the cement composition.

  As a result of intensive studies, the present inventors have specified a polymer having a specific proportion of a structural group derived from vinyl ether (a), a carboxy structural group (b), and a nitrogen-containing structural group (c) ( It has been found that A) is excellent in dispersibility, in particular, enables water reduction of the cement composition, further improves fluidity, and is useful as an excellent cement admixture, and has completed the present invention.

  That is, this invention consists of a structure shown to the following 1) -3).

1) Formula I (wherein R ¹ represents H, an aliphatic hydrocarbon group having 1 to 5 carbon atoms, p is 0 to 3, and AO is an oxyalkylene group having 2 to 4 carbon atoms) One or a mixture of two or more types, and in the case of two or more types, they may be added in blocks or randomly, m is 0 to 200, R ² is H, carbon number 1 1 to 99% by mass of a structural group (a) represented by

Formula IIa and / or IIb (wherein M represents H, a monovalent or divalent metal cation, an ammonium ion, an organic amine group, X represents —OM, —O— (AO) m—R ³ , — NR ⁴ R ⁵ , R ³ is H, a hydrocarbon group having 1 to 18 carbon atoms, R ⁴ and R ⁵ are the same or different, and H, a hydrocarbon group having 1 to 18 carbon atoms, —O - (AO) represents an ^{m-R 3, M, AO} , m represents the same as above, Y is oxygen, ^{N-R 6, R 6} is H, a hydrocarbon group having 1 to 18 carbon atoms, - (AO) m-R ³ , AO, m, R ³ represent the above-mentioned structural group (b) 1 to 99% by mass,

Formula III (wherein R ⁷ and R ⁸ are each independently H, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or 6 carbon atoms) Represents an aryl group having ˜12 or an acyl group having 1 to 12 carbon atoms, and in this case, one of R ⁷ and R ⁸ is other than a hydrogen atom, or R ⁷ —NR ⁸ is saturated, unsaturated or aromatic Represents a constituent of a 5-membered heterocyclic 5-membered ring, which ring additionally contains up to 2 heteroatoms or up to 2 keto functional groups selected from nitrogen and oxygen atoms Or a polymer (A) containing at least 1 to 99% by mass of a structural group (c) represented by the formula (A), which may be optionally condensed to a benzene ring) Agent.

  2) The above 1) wherein the structural group (b) is represented by the formula IV (wherein M1 and M2 each independently represents H, a monovalent or divalent metal cation, an ammonium ion, or an organic amine group). The dispersant described in 1.

3) The molar ratio of the structural group (a), the structural group (b), and the structural group (c) is (b) / {(a) + (c)} = 0.1 to 1.5 Item 2. The cement admixture according to Item 1. The dispersant as described in 1) above.

  The dispersant of the present invention comprises the specific polymer (A), and in particular, the cement composition can be reduced in water and further fluidized to give a cement composition with good workability. As excellent.

The present invention will be described in detail below.

  The polymer (A) constituting the dispersant of the present invention comprises at least three structural groups (a), (b), and (c). The structural group (a) has a structure represented by the formula I,

In the formula, R ¹ represents H, an aliphatic hydrocarbon group having 1 to 5 carbon atoms, p is 0 to 3, and AO is one or two kinds of oxyalkylene groups having 2 to 4 carbon atoms. It is a mixture of the above, and in the case of 2 or more types, it may be added in block form or randomly, m is 0-200, R ² is H, hydrocarbon having 1 to 18 carbon atoms Represents a group. Preferably, p is 0 to 1, and more preferably p is 0. Moreover, m represents the repeating number of alkylene oxide, Preferably, m is 0-100, Furthermore, m is 0-80, Most preferably, m is 0-40. In addition, when the alkylene group is contained in the structural group (b) described later, p in the structural group (a) is preferably 0. R ¹ is preferably a hydrocarbon group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group. As a method for introducing the structural group (a), a precursor of the structural group (a) such as hydroxyalkyl vinyl ether is previously incorporated in the polymer, and then a part constituting the structural group (a) such as polyalkylene oxide. Can be introduced by reacting with the structural group (a) precursor incorporated in the polymer, or can be introduced by using the monomer represented by the formula V as a polymerization component.

In the formula V, R ¹ , p, AO, m, and R ² are the same as those described above. Specifically, for unsaturated alcohols such as allyl alcohol, 3-methyl-3-buten-1-ol, 3-methyl-2-buten-1-ol, 2-methyl-3-buten-2-ol, etc. Compounds obtained by addition of alkylene oxides or etherification with halides, dehydration of polyalkylene glycols and / or alkyl polyalkylene glycols, or polyalkylene glycol mono- and / or alkyl polyalkylene glycol mono-monochlorides. Examples thereof include terminal vinyl compounds obtained by dehydrochlorination of rides, and vinyl compounds obtained by a Reppe reaction between acetylene and a compound having active hydrogen.
The structural group (b) has a structure of maleic acid represented by the formula IIa and / or the formula IIb or a derivative thereof,

Wherein, M represents H, a monovalent or divalent metal cation, ammonium ion, an organic amine group, X represents ^{-OM, -O- (AO) m-} R 3, a ^-NR 4 ^{R 5,} R ³ is H, a hydrocarbon group having 1 to 18 carbon atoms, and R ⁴ and R ⁵ are the same or different, and H, a hydrocarbon group having 1 to 18 carbon atoms, —O— (AO) m—R ³ , M, AO, m represents the above, Y is oxygen, N—R ⁶ , R ⁶ is H, a hydrocarbon group having 1 to 18 carbon atoms, — (AO) m—R ³ And AO, m and R ³ represent the above. m represents the number of repeating alkylene oxides, preferably m is 0 to 100, more preferably m is 0 to 80, and most preferably m is 0 to 40. R3 is preferably a hydrocarbon group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group. In particular, a structure derived from maleic acid and / or a salt of maleic acid is preferable, and a structure represented by Formula IV is preferable.

In the formula, M1 and M2 each independently represent H, a monovalent or divalent metal cation, an ammonium ion, or an organic amine group.
As a method for introducing the structural group (b), a structural group (b) precursor such as maleic anhydride or maleic acid is previously incorporated into the polymer, and then a metal hydroxide compound, polyalkylene oxide, alkylamine, or the like is used. The structural group (b) can be introduced by reacting a part of the structural group (b) with the structural group (b) precursor incorporated in the polymer, and the monomer represented by the formula VI and / or the formula VII It can introduce | transduce by using as a polymerization component.

Wherein, M represents H, a monovalent or divalent metal cation, ammonium ion, an organic amine group, X represents ^{-OM, -O- (AO) m-} R 3, a ^-NR 4 ^{R 5,} R ³ is H, a hydrocarbon group having 1 to 18 carbon atoms, and R ⁴ and R ⁵ are the same or different, and H, a hydrocarbon group having 1 to 18 carbon atoms, —O— (AO) m—R ³ , M, AO, m represents the above, Y is oxygen, N—R ⁶ , R ⁶ is H, a hydrocarbon group having 1 to 18 carbon atoms, — (AO) m—R ³ And AO, m and R ³ represent the above. m represents the number of repeating alkylene oxides, preferably m is 0 to 100, more preferably m is 0 to 80, and most preferably m is 0 to 40. R3 is preferably a hydrocarbon group having 1 to 4 carbon atoms such as a methyl group, an ethyl group, a propyl group, or a butyl group.
Furthermore, it is preferable to use a monomer represented by the formula IX as a polymerization component in order to introduce the structural group (b).

In the formula, M1 and M2 each independently represent H, a monovalent or divalent metal cation, an ammonium ion, or an organic amine group.
The structural group (c) is a structure having a nitrogen atom represented by the formula III,

In the formula, R ⁷ and R ⁸ are each independently H, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an alkyl group having 6 to 12 carbon atoms. An aryl group or an acyl group having 1 to 12 carbon atoms is represented, and in this case, one of R ⁷ and R ⁸ is other than a hydrogen atom. Or R ⁷ -NR ⁸ represents a component of a saturated, unsaturated or aromatic heterocyclic 5-membered to 7-membered ring, and this ring can additionally contain up to two selected from nitrogen and oxygen atoms The heteroatoms or up to two keto functional groups, or may be additionally fused to a benzene ring. Specifically, it has a pyrrolidone skeleton, an acetylamino skeleton or the like, and specifically, preferably has a pyrrolidone skeleton. Examples of the method for introducing the structural group (c) include a method using a monomer represented by the formula VIII as a polymerization component.

In the formula, R ⁷ and R ⁸ are each independently H, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or an alkyl group having 6 to 12 carbon atoms. An aryl group or an acyl group having 1 to 12 carbon atoms is represented, and in this case, one of R ⁷ and R ⁸ is other than a hydrogen atom. Or R ⁷ -NR ⁸ represents a component of a saturated, unsaturated or aromatic heterocyclic 5-membered to 7-membered ring, and this ring can additionally contain up to two selected from nitrogen and oxygen atoms The heteroatoms or up to two keto functional groups, or may be additionally fused to a benzene ring. Specifically, N-vinylsuccinimide, N-vinylcarbazole, 1-vinylimidazole, N-vinylcaprolactam, N-vinyloxazolidone, N-vinylpyrrolidone, N-vinylformamide, N-methyl-N-vinylformamide, N-vinylacetamide, N-methyl-N-vinylacetamide and the like can be mentioned, and N-vinylpyrrolidone is preferable.
The mass ratio of these structural groups (a), (b), and (c) is such that (a) is 1 to 99% by mass and (b) is the total of (a), (b), and (c). 1 to 99% by mass, (c) is in the range of 1 to 99% by mass, preferably (a) is 10 to 90% by mass, (b) is 5 to 90% by mass, and (c) is 1 to 50%. More preferably, (a) is 10 to 90% by mass, (b) is 5 to 30% by mass, and (c) is 1 to 50% by mass. If it is out of this range, the dispersibility is lowered, which is not preferable.
The molar ratio of these structural groups (a), (b), (c) is preferably in the range of (b) / {(a) + (c)} = 0.1 to 1.5, More preferably, it is 0.2-1.2. If it is out of this range, the dispersibility decreases. The weight ratio and molar ratio of each structural group (a), (b), (c) shown above can be determined from the weight and the number of moles of each monomer used for polymerization.
The dispersant of the present invention comprises the polymer (A) having at least the structural groups (a), (b), and (c), but may have other structural groups as necessary. Such other structural group is preferably 50% by mass or less, more preferably 30% by mass or less, and particularly preferably 5% by mass or less, based on the entire polymer (A). Specifically, it can be introduced by copolymerizing monomers such as acrylamide, styrene, methylstyrene, vinyl acetate, indene, (meth) acrylic acid, and (meth) acrylic ester.

  In order to obtain the polymer (A) in the present invention, for example, a monomer serving as a precursor of each structural group or a monomer represented by the formulas V, VI, VII, VIII, IX is used with a polymerization initiator. What is necessary is just to superpose | polymerize. The polymerization can be performed by a method such as polymerization in a solvent or bulk polymerization. The solution polymerization can be carried out batchwise or continuously, and the solvent used in that case is not particularly limited. For example, water; alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol; benzene, toluene, xylene, Aromatic or aliphatic hydrocarbons such as cyclohexane and n-hexane; ester compounds such as ethyl acetate; ketone compounds such as acetone and methyl ethyl ketone; and cyclic ether compounds such as tetrahydrofuran and dioxane.

  When aqueous solution polymerization is performed, as a radical polymerization initiator, a water-soluble polymerization initiator, for example, a persulfate such as ammonium persulfate, sodium persulfate, or potassium persulfate; hydrogen peroxide; 2,2′-azobis- Azoamidine compounds such as 2-methylpropionamidine hydrochloride, cyclic azoamidine compounds such as 2,2′-azobis-2- (2-imidazolin-2-yl) propane hydrochloride, and azonitriles such as 2-carbamoylazoisobutyronitrile Water-soluble azo initiators such as compounds are used. In this case, alkali metal sulfites such as sodium hydrogen sulfite, metabisulphite, sodium hypophosphite, Fe (II) salts such as Mole salt, hydroxymethanesulfine Acid sodium dihydrate, hydroxylamine hydrochloride, thiourea, L-ascorbic acid (salt), erythorbium Accelerator such as acid (salt) (reducing agent) can be used in combination. Among them, a combination of hydrogen peroxide and an organic reducing agent is preferable. As the organic reducing agent, L-ascorbic acid (salt), L-ascorbic acid ester, erythorbic acid (salt), erythorbic acid ester, and the like are preferable. is there. These radical polymerization initiators and accelerators (reducing agents) may be used alone or in combination of two or more.

In addition, when performing solution polymerization using a lower alcohol, aromatic or aliphatic hydrocarbon, ester compound, or ketone compound as a solvent, or when performing bulk polymerization, benzoyl peroxide, lauroyl peroxide, sodium peroxide Peroxides such as oxides; hydroperoxides such as t-butyl hydroperoxide and cumene hydroperoxide; azo compounds such as azobisisobutyronitrile and the like are used as radical polymerization initiators. 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 radical polymerization initiators or combinations of radical polymerization initiators and accelerators. In addition, although superposition | polymerization temperature is suitably determined by the solvent and polymerization initiator to be used, it is normally performed within the range of 0-150 degreeC.
The method of charging each monomer into the reaction vessel is not particularly limited, the method of initially charging the entire amount into the reaction vessel at once, the method of dividing or continuously charging the entire amount into the reaction vessel, and the initial charging into the reaction vessel. Any method may be employed in which the remainder is divided or continuously charged into the reaction vessel. Also, by changing the charging rate of each monomer into the reaction vessel during the reaction continuously or stepwise, the weight ratio of each monomer charged per unit time can be changed continuously or stepwise. You may make it synthesize | combine the mixture of the polymer (A) from which the ratio of structural group (a), (b), (c) in unification | combination (A) differs. The radical polymerization initiator may be charged into the reaction vessel from the beginning, may be dropped into the reaction vessel, or may be combined according to the purpose.

  A chain transfer agent can be used for adjusting the molecular weight of the resulting polymer (A). The chain transfer agent is not particularly limited. For example, thiol chain transfer agents such as mercaptoethanol, thioglycerol, thioglycolic acid, 3-mercaptopropionic acid, thiomalic acid, and 2-mercaptoethanesulfonic acid; 2 such as isopropyl alcohol Secondary alcohol: Phosphorous acid, hypophosphorous acid and salts thereof (sodium hypophosphite, potassium hypophosphite, etc.), sulfurous acid, hydrogen sulfite, dithionite, metabisulfite and salts thereof (sodium sulfite, sulfurous acid) Known hydrophilic chain transfer agents such as lower oxides of sodium hydrogen, sodium dithionite, sodium metabisulfite, and the like and salts thereof can be used. Furthermore, the use of a hydrophobic chain transfer agent is effective for improving the viscosity of the cement composition. Hydrophobic chain transfer agents include 3 or more carbon atoms such as butanethiol, octanethiol, decanethiol, dodecanethiol, hexadecanethiol, octadecanethiol, cyclohexyl mercaptan, thiophenol, octyl thioglycolate, octyl 3-mercaptopropionate, etc. It is preferable to use a thiol chain transfer agent having the following hydrocarbon group. Two or more types of chain transfer agents can be used in combination, and a hydrophilic chain transfer agent and a hydrophobic chain transfer agent may be used in combination. Furthermore, in order to adjust the molecular weight of the polymer (A), it is also effective to use a monomer having high chain mobility such as (meth) allylsulfonic acid (salt).

  In the above polymerization, in order to obtain a polymer (A) having a predetermined molecular weight with good reproducibility, it is necessary to allow the polymerization reaction to proceed stably. Therefore, in the case of solution polymerization, the solvent used at 25 ° C. The dissolved oxygen concentration is preferably in the range of 5 ppm or less. Preferably it is the range of 0.01-4 ppm, More preferably, it is the range of 0.01-2 ppm, Most preferably, it is the range of 0.01-1 ppm. When nitrogen substitution or the like is performed after the monomer is added to the solvent, the dissolved oxygen concentration of the system including the monomer is within the above range.

The adjustment of the dissolved oxygen concentration of the solvent may be performed in a polymerization reaction tank, or a solution in which the amount of dissolved oxygen is adjusted in advance may be used. As a method for expelling oxygen in the solvent, for example, the following (1) The method of (5) is mentioned.
(1) After pressure-filling an inert gas such as nitrogen in a sealed container containing a solvent, the partial pressure of oxygen in the solvent is lowered by lowering the pressure in the sealed container. You may reduce the pressure in an airtight container under nitrogen stream.
(2) The liquid phase portion is vigorously stirred for a long time while the gas phase portion in the container containing the solvent is replaced with an inert gas such as nitrogen.
(3) An inert gas such as nitrogen is bubbled in the solvent in the container for a long time.
(4) The solvent is once boiled and then cooled in an inert gas atmosphere such as nitrogen.
(5) A static mixer (static mixer) is installed in the middle of the pipe, and an inert gas such as nitrogen is mixed in the pipe for transferring the solvent to the polymerization reaction tank.

  The polymer (A) obtained by the above copolymerization is used as it is as an essential component of the dispersant of the present invention as it is, but from the viewpoint of handleability, it should be adjusted to a pH range of weak acid or higher in an aqueous solution state. More preferably, it is in the range of pH 4 or more, more preferably pH 5 or more, particularly preferably pH 6 or more. On the other hand, the copolymerization reaction may be carried out at a pH of 7 or more. In this case, however, the polymerization rate decreases, and at the same time, the copolymerizability deteriorates and the dispersion performance deteriorates. It is preferable to carry out the reaction, more preferably less than pH 6, more preferably less than pH 5.5, particularly preferably less than pH 5. Therefore, it is preferable to adjust to a higher pH by adding an alkaline substance after carrying out the copolymerization reaction at a low pH. Specifically, as a preferred embodiment, the alkaline substance is specifically used after carrying out the copolymerization reaction at a pH of less than 6. To adjust the pH to 6 or more by adding a pH, a method of adding an alkaline substance after carrying out a copolymerization reaction at a pH below 5, and adding an alkaline substance after carrying out a copolymerization reaction at a pH below 5 or less. The method etc. which adjust to pH6 or more are mentioned. The pH can be adjusted using, for example, an alkaline substance such as inorganic salt such as hydroxide or carbonate of monovalent metal or divalent metal; ammonia; organic amine; Also, when it is necessary to lower the pH, particularly when pH adjustment is required during polymerization, phosphoric acid, sulfuric acid, nitric acid, alkyl phosphoric acid, alkyl sulfuric acid, alkylsulfonic acid, (alkyl) benzenesulfonic acid, etc. It is possible to adjust the pH using an acidic substance, and among these acidic substances, phosphoric acid is preferred from the viewpoint of having a pH buffering action. Further, after the reaction, the concentration can be adjusted if necessary.

  The weight average molecular weight of the polymer (A) is suitably 1,000 to 500,000 in terms of polyethylene glycol by gel permeation chromatography (hereinafter also referred to as “GPC”). 000 is preferable, and 10,000 to 150,000 is more preferable. By selecting such a range of the weight average molecular weight, a dispersant exhibiting higher dispersion performance can be obtained.

  The dispersant of the present invention can contain an antifoaming agent, and the polymer (A) according to the present invention may be added after the production, or may be added before the polymerization is started or during the polymerization. . The addition ratio is preferably 0.0001 to 10% by mass with respect to the total mass of the polymer (A), specifically, polyoxyalkylenes such as (poly) oxyethylene (poly) oxypropylene adducts; Polyoxyalkylene alkyl ethers such as diethylene glycol heptyl ether, polyoxyethylene oleyl ether, polyoxypropylene butyl ether, polyoxyethylene polyoxypropylene 2-ethylhexyl ether, oxyethyleneoxypropylene adducts with higher alcohols having 12 to 14 carbon atoms Polyoxyalkylene (alkyl) aryl ethers such as polyoxypropylene phenyl ether and polyoxyethylene nonyl phenyl ether; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5 Acetylene ethers obtained by addition polymerization of alkylene oxide to acetylene alcohols such as dimethyl-3-hexyne-2,5-diol and 3-methyl-1-butyn-3-ol; diethylene glycol oleate, diethylene glycol laurate, ethylene (Poly) oxyalkylene fatty acid esters such as glycol distearate; polyoxyalkylene sorbitan fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan trioleate; polyoxypropylene methyl ether sodium sulfate, poly Polyoxyalkylene alkyl (aryl) ether sulfates such as sodium oxyethylene dodecyl phenyl ether sulfate; polyoxy Polyoxyalkylene alkyl phosphates such as tylene stearyl phosphate; polyoxypropylene polyoxyethylene laurylamine (1-20 mol addition of propylene oxide, 1-20 mol addition product of ethylene oxide, etc.), curing with addition of alkylene oxide Polyoxyalkylene alkylamines such as beef tallow amine (1-20 mol addition of propylene oxide, 1-20 mol addition product of ethylene oxide, etc.); polyoxyalkylene amide and the like. Two or more of these antifoaming agents may be used in combination.

  The dispersant of the present invention may be used in the form of an aqueous solution, or it is neutralized with a divalent metal hydroxide such as calcium or magnesium after polymerization to be a polyvalent metal salt and then dried, It is supported by inorganic powder such as silica-based fine powder and dried, or it is dried and solidified into a thin film on a support using a drum-type drying device, a disk-type drying device or a belt-type drying device, and then pulverized. The powder may be used as a powder. Alternatively, the powdered dispersant of the present invention may be blended in advance with a water-free cement composition such as cement powder or dry mortar, and used as a premix product for plastering, floor finishing, grout, etc. It may be good or may be blended when the cement composition is kneaded.

  The dispersant of the present invention is useful as a cement admixture, and can be used for various hydraulic materials, that is, cement compositions such as cement and gypsum and other hydraulic materials. As a specific example of a hydraulic composition containing such a hydraulic material, water and the cement admixture of the present invention, and further containing fine aggregate (sand, etc.) and coarse aggregate (crushed stone, etc.) as necessary Examples include cement paste, mortar, concrete, plaster and the like.

  Among the hydraulic compositions, a cement composition using cement as a hydraulic material is the most common, and the cement composition includes the dispersant of the present invention, cement, and water as essential components. Such a cement composition is one of the preferred embodiments of the present invention.

  There is no limitation in particular as a cement used in the said cement composition. For example, Portland cement (ordinary, early strength, very early 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, Super fast cement (1 clinker fast cement, 2 clinker fast cement, magnesium phosphate cement), grout cement, oil well cement, low exothermic cement (low exothermic blast furnace cement, fly ash mixed low exothermic blast furnace cement, belite High-concentration cement), ultra-high-strength cement, cement-based solidified material, eco-cement (city waste incineration ash, sewage sludge incineration ash as a raw material), blast furnace slag, fly ash , Cinder ash, clinker ash, Squash, silica fume, silica powder, a fine powder and gypsum limestone powder may be added. In addition to gravel, crushed stone, granulated slag, recycled aggregate, etc., the aggregate includes siliceous, clay, zircon, high alumina, silicon carbide, graphite, chrome, chromic, magnesia. Refractory aggregate such as can be used.

In the cement composition, the unit water amount per 1 m ³ , the cement use amount and the water / cement ratio are as follows: unit water amount 100 to 185 kg / m ³ , use cement amount 200 to 800 kg / m ³ , water / cement ratio ( (Mass ratio) = 0.1 to 0.7, more preferably, unit water amount 120 to 175 kg / m ³ , amount of cement used 250 to 800 kg / m ³ , water / cement ratio (mass ratio) = 0. .2 to 0.65 is recommended, and can be used widely from poor blends to rich blends. The dispersant of the present invention is in a high water reduction rate region, that is, in a region where the water / cement ratio is low, such as water / cement ratio (mass ratio) = 0.15 to 0.5 (preferably 0.15 to 0.4). Furthermore, it is effective for both high-strength concrete having a large unit cement amount and a small water / cement ratio, and poor-mixed concrete having a unit cement amount of 300 kg / m ³ or less.

  As a mixing ratio of the dispersant of the present invention in the cement composition, for example, when used for mortar or concrete using hydraulic cement, 0.01 to 10.0% by mass of the cement mass in terms of solid content It is preferable that Such an added amount brings about various preferable effects such as reduction in unit water amount, increase in strength, and improvement in durability. If the blending ratio is less than 0.01%, the performance may not be sufficient. On the other hand, even if a large amount exceeding 10.0% is used, the effect is practically peaked and also from the economical aspect. May be disadvantageous. The preferred range of the blending ratio is more preferably 0.02 to 5.0% by mass, still more preferably 0.05 to 3.0% by mass, and particularly preferably 0.1 to 2.0% by mass. It is.

  The cement composition has high dispersibility and dispersion holding performance even in a high water reduction rate region, and exhibits sufficient initial dispersibility and viscosity reduction even at low temperatures, and has excellent workability. , Ready mixed concrete, concrete for concrete secondary products (precast concrete), centrifugal molding concrete, concrete for vibration compaction, steam-cured concrete, sprayed concrete, etc. High fluidity is required such as concrete in the range of 22-25 cm), high-fluidity concrete (concrete with a slump value of 25 cm or more and a slump flow value of 50-70 cm), self-filling concrete, self-leveling material, etc. It is also effective for mortar and concrete.

  The dispersant of the present invention can be used in combination with a known cement dispersant, and a plurality of known cement dispersants can be used in combination. As a well-known cement dispersant used together, the sulfonic acid-type dispersing agent (S) which has a sulfonic acid group in a molecule | numerator is preferable. By using a sulfonic acid-based dispersant (S) having a sulfonic acid group in the molecule, cement brand and lot no. Regardless of this, the cement admixture exhibits stable dispersion performance. The sulfonic acid dispersant (S) is a dispersant that exhibits dispersibility with respect to cement due to electrostatic repulsion mainly caused by sulfonic acid groups, and various known sulfonic acid dispersants can be used. A compound having an aromatic group in the molecule is preferable. Specifically, polyalkylaryl sulfonates such as naphthalene sulfonic acid formaldehyde condensate, methyl naphthalene sulfonic acid formaldehyde condensate, anthracene sulfonic acid formaldehyde condensate; melamine formalin resin sulfonate such as melamine sulfonic acid formaldehyde condensate Aromatic aminosulfonates such as aminoaryl sulfonic acid-phenol-formaldehyde condensates; lignin sulfonates such as lignin sulfonates and modified lignin sulfonates; various sulfonic acids such as polystyrene sulfonates System dispersants. In the case of concrete with a high water / cement ratio, a lignin sulfonate-based dispersant is preferably used, while in the case of a concrete with a medium water / cement ratio that requires higher dispersion performance, Dispersants such as alkylaryl sulfonate, melamine formalin sulfonate, aromatic amino sulfonate, and polystyrene sulfonate are preferably used. Two or more sulfonic acid-based dispersants (S) having a sulfonic acid group in the molecule may be used in combination.

  The dispersant of the present invention can be used in combination with the oxycarboxylic acid compound (D) in addition to the sulfonic acid dispersant (S). By including the oxycarboxylic acid compound (D), higher dispersion retention performance can be exhibited even in a high temperature environment. As the oxycarboxylic acid compound (D) used in the present invention, an oxycarboxylic acid having 4 to 10 carbon atoms or a salt thereof is preferable, for example, gluconic acid, glucoheptonic acid, aravic acid, malic acid, citric acid, These include inorganic or organic salts such as sodium, potassium, calcium, magnesium, ammonium, triethanolamine and the like. Among these, gluconic acid or a salt thereof is preferably used. In addition, these may be used independently and may use 2 or more types together. In particular, in the case of poor blended concrete, a lignin sulfonate-based dispersant is used as the sulfonic acid-based dispersant (S) having a sulfonic acid group in the molecule, and gluconic acid or oxycarboxylic acid-based compound (D) is gluconic acid or It is preferable to use the salt.

  When the dispersant of the present invention and the sulfonic acid-based dispersant (S) are used in combination, the blending ratio of the polymer (A) and the sulfonic acid-based dispersant (S) in the dispersant of the present invention, that is, the solid content The (polymer (A) / sulfonic acid dispersant (S)) (% by mass) in terms of conversion is preferably from 1 to 99/99 to 1, more preferably from 5 to 95/95 to 5, and more preferably from 10 to 90 / 90-10 are more preferable, and 20-80 / 80-20 are especially preferable. When the dispersant of the present invention and the oxycarboxylic acid compound (D) are used in combination, the blending ratio of the polymer (A) and the oxycarboxylic acid compound (D) in the dispersant of the present invention, that is, The (polymer (A) / oxycarboxylic acid compound (D)) (mass%) in terms of solid content is preferably from 1 to 99/99 to 1, more preferably from 5 to 95/95 to 5, 90/90 to 10 is more preferable, and 20 to 80/80 to 20 is particularly preferable. Furthermore, when the three components of the cement admixture of the present invention, the sulfonic acid-based dispersant (S) having a sulfonic acid group in the molecule, and the oxycarboxylic acid compound (D) are used in combination, The blending ratio of the union (A), the sulfonic acid-based dispersant (S) having a sulfonic acid group in the molecule and the oxycarboxylic acid compound (D), that is, (polymer (A) / in molecule The sulfonic acid-based dispersant (S) / oxycarboxylic acid compound (D)) (mass%) having a sulfonic acid group in the range of 1 to 98/1 to 98/1 to 98 is preferable, and 5 to 90/5. -90 / 5-90 are more preferable, 10-90 / 5-85 / 5-85 are still more preferable, and 20-80 / 10-70 / 10-70 are especially preferable.

Moreover, the said cement composition can contain the other well-known cement additive (material) which is illustrated to the following (1)-(11).
(1) Water-soluble polymer material: polyacrylic acid (sodium), polymethacrylic acid (sodium), polymaleic acid (sodium), unsaturated carboxylic acid polymer such as sodium salt of acrylic acid / maleic acid copolymer; methylcellulose Nonionic cellulose ethers such as ethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, hydroxypropyl cellulose; alkylated or hydroxyalkylated derivatives of polysaccharides such as methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose Hydrophobic substituents in which some or all of the hydroxyl atoms have a hydrocarbon chain having 8 to 40 carbon atoms as a partial structure, sulfonic acid groups or Polysaccharide derivatives substituted with an ionic hydrophilic substituent having a partial structure of these salts; yeast glucan, xanthan gum, β-1.3 glucans (which may be either linear or branched, examples include Polysaccharides produced by microbial fermentation such as curdlan, paramylon, pachyman, scleroglucan, laminaran, etc.); polyacrylamide; polyvinyl alcohol; starch; starch phosphate ester; sodium alginate; gelatin; A copolymer of acrylic acid having quaternary compounds and quaternary compounds thereof.
(2) Polymer emulsion: Copolymers of various vinyl monomers such as alkyl (meth) acrylate.
(3) Curing retarders other than oxycarboxylic acid compounds (D): monosaccharides such as glucose, fructose, galactose, saccharose, xylose, apiose, ribose, isomerized sugar, oligosaccharides such as disaccharide and trisaccharide, Or oligosaccharides such as dextrin, or polysaccharides such as dextran, sugars such as molasses containing them; sugar alcohols such as sorbitol; magnesium silicates; phosphoric acid and salts thereof or boric acid esters; Salt; Alkali-soluble protein; Humic acid; Tannic acid; Phenol; Polyhydric alcohol such as glycerin; Aminotri (methylenephosphonic acid), 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetra (methylenephosphonic acid), diethylenetriamine Penta (methylenephosphonic acid) and these Alkali metal salts, and phosphonic acids and derivatives thereof such as alkaline earth metal salts.
(4) Early strengthening agents / accelerators: 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.
(5) Antifoaming agents other than oxyalkylene-based: mineral oil-based antifoaming agents such as coconut oil and liquid paraffin; , 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 monolaurate, sorbitol trioleate, natural wax; octyl alcohol, hexadecyl Alcohol defoamers such as alcohol, acetylene alcohol and glycols; Amide defoamers such as acrylate polyamines; Phosphate ester defoamers such as tributyl phosphate and sodium octyl phosphate; Aluminum stearate, calcium oleate, etc. Metal soap defoaming ; Dimethyl silicone oil, silicone paste, silicone emulsion, organic modified polysiloxane (dimethyl polysiloxane polyorganosiloxane), silicone anti-foaming agent such as fluorosilicone oil.
(6) AE agent: resin soap, saturated or unsaturated fatty acid, 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, alkenyl sulfosuccinic acid, α-olefin sulfonate, and the like.
(7) Other surfactants: aliphatic monohydric alcohol having 6 to 30 carbon atoms in the molecule such as octadecyl alcohol and stearyl alcohol, and 6 to 30 carbon atoms in the molecule such as abiethyl alcohol Intramolecular such as alicyclic monohydric alcohol, dodecyl mercaptan, etc. Intramolecular such as monovalent mercaptan having 6-30 carbon atoms in the molecule, such as nonylphenol, alkylphenol having 6-30 carbon atoms in the molecule, dodecylamine, etc. 10 mol or more of an alkylene oxide such as ethylene oxide or propylene oxide was added to a carboxylic acid having 6 to 30 carbon atoms in the molecule such as an amine having 6 to 30 carbon atoms, lauric acid or stearic acid. Polyalkylene oxide derivatives having an alkyl group or an alkoxy group as a substituent Good, alkyl diphenyl ether sulfonates in which two phenyl groups having a sulfone group are ether-bonded; various anionic surfactants; various cationic surfactants such as alkylamine acetate and alkyltrimethylammonium chloride; various nonionic interfaces Activators; various amphoteric surfactants.
(8) Waterproofing agent: fatty acid (salt), fatty acid ester, oil and fat, silicon, paraffin, asphalt, wax and the like.
(9) Rust preventive: nitrite, phosphate, zinc oxide and the like.
(10) Crack reducing agent: polyoxyalkyl ether and the like.
(11) Expansion material: Ettlingite, coal, etc.

  Other known cement additives (materials) include cement wetting agents, thickeners, separation reducing agents, flocculants, drying shrinkage reducing agents, strength enhancers, self-leveling agents, rust preventives, colorants, and antifungal agents. An agent etc. can be mentioned. These known cement additives (materials) may be used alone or in combination of two or more.

  In the above cement composition, the following (1) to (4) may be mentioned as particularly preferred embodiments for components other than cement and water.

  (1) <1> A combination comprising essentially the two components of the dispersant of the present invention and <2> an oxyalkylene-based antifoaming agent. As the oxyalkylene-based antifoaming agent, polyoxyalkylenes, polyoxyalkylene alkyl ethers, polyoxyalkylene acetylene ethers, polyoxyalkylene alkylamines and the like can be used, but polyoxyalkylene alkylamines are particularly preferable. Is preferred. The blending mass ratio of the oxyalkylene antifoaming agent <2> is preferably in the range of 0.01 to 20% by mass with respect to the cement admixture <1>.

  (2) A combination comprising two components, <1> the dispersant of the present invention and <2> a material separation reducing agent. Examples of the material separation reducing agent include various thickeners such as nonionic cellulose ethers, a hydrophobic substituent composed of a hydrocarbon chain having 4 to 30 carbon atoms as a partial structure, and an alkylene oxide having 2 to 18 carbon atoms. A compound having a polyoxyalkylene chain added in an average addition mole number of 2 to 300 can be used. The blending mass ratio of the cement admixture <1> and the material separation reducing agent <2> is preferably 10/90 to 99.99 / 0.01, and 50/50 to 99.9 / 0. 1 is more preferable. The cement composition of this combination is suitable as high fluidity concrete, self-filling concrete and self-leveling material.

  (3) A combination comprising essentially two components, <1> the dispersant of the present invention and <2> an accelerator. As the accelerator, soluble calcium salts such as calcium chloride, calcium nitrite and calcium nitrate, chlorides such as iron chloride and magnesium chloride, formates such as thiosulfate, formic acid and calcium formate, and the like can be used. The blending mass ratio of the <1> cement admixture and the <2> accelerator is preferably 10/90 to 99.9 / 0.1, and more preferably 20/80 to 99/1.

(4) A combination comprising essentially the three components of <1> the dispersant of the present invention, <2> an oxyalkylene antifoaming agent, and <3> an AE agent. As the oxyalkylene-based antifoaming agent, polyoxyalkylenes, polyoxyalkylene alkyl ethers, polyoxyalkylene acetylene ethers, polyoxyalkylene alkylamines and the like can be used, but polyoxyalkylene alkylamines are particularly preferable. Is preferred. The blending mass ratio of the cement admixture <1> and the antifoaming agent <2> is preferably 0.01 to 20% by mass with respect to the cement admixture <1>. On the other hand, the blending mass ratio of the AE agent <3> is preferably 0.001 to 2 mass% with respect to the cement.

The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. Unless otherwise specified, “%” represents mass% and “part” represents mass part.

<Example 1>
A reactor equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel was charged with 16.32 g (0.17 mol) of maleic anhydride and 100 g of toluene and heated to 75 ° C. Next, methoxy polyethylene glycol vinyl ether (molecular weight 938, containing 20 ethylene oxide units on average per molecule) 140.07 g (0.15 mol), N-vinylpyrrolidone 59.94 g (0.54 mol), toluene 200 g, and A mixed solution of 2.2'-azobis (2-methylbutyronitrile) 0.35 g was added dropwise over 1 hour. After dropping, the mixture is kept at 75 to 80 ° C., followed by heating and stirring for 4 hours. Thereafter, toluene is distilled off under reduced pressure, water containing 8.16 g of NaOH is added, and an aqueous dispersant solution containing 20% polymer solids ( P-1) was obtained. The ratio (b) / {(a) + (c)} of each structural group in this polymer is 0.25.

<Example 2>
In a reactor equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel, maleic anhydride 23.91 g (0.244 mol), toluene 100 g, and methoxypolyethylene glycol vinyl ether (molecular weight 938, average per molecule) 144.10 g (0.158 mol) containing 20 ethylene oxide units), heated at 75 ° C. for 2 hours, 20.00 g (0.232 mol) butyl vinyl ether, 9.99 g (0.09 mol) N-vinylpyrrolidone And a mixed solution of 2.23 g of 2.2′-azobis (2-methylbutyronitrile) was added dropwise over 1 hour. After dropping, the mixture is kept at 75 to 80 ° C., followed by heating and stirring for 4 hours. Thereafter, toluene is distilled off under reduced pressure, water containing 3.10 g of NaOH is added, and an aqueous dispersant solution containing 20% polymer solids ( P-2) was obtained. The ratio (b) / {(a) + (c)} of each structural group in this polymer is 0.76.

<Comparative Example 1>
A reactor equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel was charged with 29.40 g (0.30 mol) of maleic anhydride and 100 g of toluene and heated to 75 ° C. Next, 168.84 g (0.18 mol) of methoxypolyethyleneglycol vinyl ether (molecular weight 938, containing an average of 20 ethylene oxide units per molecule) and 2.2'-azobis (2-methylbutyronitrile) 0. 19 g of the mixed solution was added dropwise over 1 hour. After dropping, the temperature is kept at 75 to 80 ° C., and the stirring is continued for 4 hours. Then, toluene is distilled off under reduced pressure, water containing 14.4 g of NaOH is added, and an aqueous dispersant solution containing 20% polymer solids ( cf-1) was obtained.

<Mortar test>
Mortar was prepared using 600 g of ordinary Portland cement (manufactured by Taiheiyo Cement), 1350 g of ISO standard sand, 200 g of tap water, and the dispersant of the present invention, and the flow value was measured. The amount of the dispersant used is indicated by the amount added in solids, and is shown in Table 1 as a percentage of the amount of cement. The mortar adjustment method and the flow value measurement method were performed according to the mixing method and the flow test in the strength test shown in JIS R5201. The results are shown in Table 1.

Claims (3)

Formula I (wherein R ¹ represents H, an aliphatic hydrocarbon group having 1 to 5 carbon atoms, p is 0 to 3, and AO is one of oxyalkylene groups having 2 to 4 carbon atoms) Or it is a mixture of 2 or more types, and in the case of 2 or more types, it may be added in block form or randomly, m is 0 to 200, R ² is H, C 1-18. 1 to 99% by mass of the structural group (a) represented by

Formula IIa and / or IIb (wherein M represents H, a monovalent or divalent metal cation, an ammonium ion, an organic amine group, X represents —OM, —O— (AO) m—R ³ , — NR ⁴ R ⁵ , R ³ is H, a hydrocarbon group having 1 to 18 carbon atoms, R ⁴ and R ⁵ are the same or different, and H, a hydrocarbon group having 1 to 18 carbon atoms, —O - (AO) represents an ^{m-R 3, M, AO} , m represents the same as above, Y is oxygen, ^{N-R 6, R 6} is H, a hydrocarbon group having 1 to 18 carbon atoms, - (AO) m-R ³ , AO, m, R ³ represent the above-mentioned structural group (b) 1 to 99% by mass,

Formula III (wherein R ⁷ and R ⁸ are each independently H, an alkyl group having 1 to 12 carbon atoms, a cycloalkyl group having 5 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or 6 carbon atoms) Represents an aryl group having ˜12 or an acyl group having 1 to 12 carbon atoms, and in this case, one of R ⁷ and R ⁸ is other than a hydrogen atom, or R ⁷ —NR ⁸ is saturated, unsaturated or aromatic Represents a constituent of a 5-membered heterocyclic 5-membered ring, which ring additionally contains up to 2 heteroatoms or up to 2 keto functional groups selected from nitrogen and oxygen atoms Or a polymer (A) containing at least 1 to 99% by mass of a structural group (c) represented by the formula (A), which may be optionally condensed to a benzene ring) Agent.

The structural group (b) is represented by the formula IV (wherein M1 and M2 each independently represent H, a monovalent or divalent metal cation, an ammonium ion, or an organic amine group). Dispersant.

The molar ratio of the structural group (a), the structural group (b), and the structural group (c) is (b) / {(a) + (c)} = 0.1 to 1.5. The dispersant described.