JP7214218B2 - Dispersant for hydraulic composition and hydraulic composition - Google Patents

Description

The present invention relates to a hydraulic composition dispersant and a hydraulic composition. More specifically, a dispersant for a hydraulic composition that imparts high fluidity to a hydraulic composition, does not delay setting, and reduces viscosity even when preparing a hydraulic composition with a significantly reduced water/binder ratio. and hydraulic compositions.

Conventionally, various water-soluble vinyl copolymers have been proposed as dispersants for hydraulic compositions (see, for example, Patent Documents 1 to 6).

However, conventionally proposed water-soluble vinyl copolymers are used to prepare a hydraulic composition with a remarkably reduced water/binder ratio in order to obtain an ultra-high-strength cured product. There is a problem that it is not possible to impart high fluidity to the curable composition, suppress deterioration of the fluidity over time, and obtain a cured product having excellent strength at the same time.

In addition, as a hydraulic composition having excellent fluidity, less deterioration over time, and less material separation, a dispersion for a hydraulic composition comprising a copolymer of two alkenyl ethers with different degrees of polymerization and maleic anhydride. A product containing an agent has been proposed (Patent Document 7).

Furthermore, even in the case of preparing a hydraulic composition with a significantly reduced water/binder ratio, the hydraulic composition is provided with high fluidity and suppresses a decrease in fluidity over time, and at the same time has excellent strength. A dispersant for a hydraulic composition and a hydraulic composition capable of obtaining a cured product with low self-shrinkage have been proposed (Patent Document 8).

JP-A-57-118058 JP-A-5-170501 JP-A-6-206750 JP-A-8-290948 JP-A-2001-48620 JP 2006-36623 A JP-A-6-48801 JP 2009-263181 A

However, when preparing a hydraulic composition with a significantly reduced water/binder ratio, the amount of powder such as cement is extremely large, so the viscosity of the hydraulic composition tends to increase. rate is likely to increase. A higher addition rate of the dispersant leads to retardation of setting of the hydraulic composition. Therefore, there is a demand for a dispersant for a hydraulic composition and a hydraulic composition that provide higher fluidity than those of Patent Documents 7 and 8, reduce the viscosity of the hydraulic composition, and do not delay the setting.

An object of the present invention is to provide a dispersant for a hydraulic composition that provides high fluidity, reduces viscosity, and does not delay setting even when preparing a hydraulic composition with a significantly reduced water / binder ratio, and water It is to provide a curable composition.

According to the present invention, the following hydraulic composition dispersant and hydraulic composition are provided.

（式（１）において、
Ｒ^１：炭素数３～５のアルケニル基
Ｒ^２Ｏ：炭素数２～３のオキシアルキレン基
Ｒ^３：水素原子、炭素数１～２２のアルキル基又は炭素数１～２２の脂肪族アシル基
ｍ：２～６５個のオキシエチレン単位で構成されたポリオキシエチレン基又は合計２～６５個のオキシエチレン単位とオキシプロピレン単位とで構成されたポリオキシアルキレン基の数）
構成単位（ｃ）：下記の式（２）で示される単量体から形成された構成単位

（式（２）において、
Ｒ^４：炭素数３～５のアルケニル基
Ｒ^５Ｏ：炭素数２～３のオキシアルキレン基
Ｒ^６：水素原子、炭素数１～２２のアルキル基又は炭素数１～２２の脂肪族アシル基
ｎ：３～６６個のオキシエチレン単位で構成されたポリオキシエチレン基又は合計３～６６個のオキシエチレン単位とオキシプロピレン単位とで構成されたポリオキシアルキレン基の数）
ただし、式（１）と式（２）において ｎ＞ｍ [1] A dispersant for a hydraulic composition for use in a hydraulic composition containing water and a binder such that the water/binder ratio by mass is 0.05 or more and less than 0.20, the structural unit A copolymer having (a), a structural unit (b) and a structural unit (c) and having a weight average molecular weight in terms of polyethylene glycol/polyethylene oxide of Mw 5000 to 20000 , and the copolymer is gel permeation The mass average molecular weight of polyethylene glycol/polyethylene oxide equivalent measured by chromatography is within the range of 10 to 32.5 times the mass average molecular weight of the monomer represented by the following formula (1), represented by formula (2). A dispersant for a hydraulic composition having a weight average molecular weight within the range of 1.5 to 7.5 times the weight average molecular weight of the monomer.
Structural unit (a): a structural unit formed from an unsaturated carboxylic acid and/or a salt thereof, and 80 to 100 mol% of the unsaturated carboxylic acid and/or a salt thereof is (anhydrous) maleic acid, fumaric acid, or Structural unit (b): a structural unit formed from a monomer represented by the following formula (1)

(In formula (1),
R ¹ : alkenyl group having 3 to 5 carbon atoms R ² O: oxyalkylene group having 2 to 3 carbon atoms R ³ : hydrogen atom, alkyl group having 1 to 22 carbon atoms or aliphatic acyl group having 1 to 22 carbon atoms m : Number of polyoxyethylene groups composed of 2 to 65 oxyethylene units or polyoxyalkylene groups composed of a total of 2 to 65 oxyethylene units and oxypropylene units)
Structural unit (c): a structural unit formed from a monomer represented by the following formula (2)

(In formula (2),
R ⁴ : alkenyl group having 3 to 5 carbon atoms R ⁵ O: oxyalkylene group having 2 to 3 carbon atoms R ⁶ : hydrogen atom, alkyl group having 1 to 22 carbon atoms or aliphatic acyl group having 1 to 22 carbon atoms n : Number of polyoxyethylene groups composed of 3 to 66 oxyethylene units or polyoxyalkylene groups composed of a total of 3 to 66 oxyethylene units and oxypropylene units)
However, in formulas (1) and (2), n>m

[2] In formula (1), (R ² O) _m is a polyoxyethylene group composed of 5 to 65 oxyethylene units, or a total of 5 to 65 oxyethylene units and oxy The dispersant for hydraulic compositions according to the above [1], which is a polyoxyalkylene group composed of propylene units.

[3] In formula (2), (R ⁵ O) _n is a polyoxyethylene group composed of 6 to 66 oxyethylene units, or a total of 6 to 66 oxyethylene units and oxy The dispersant for hydraulic compositions according to the above [1] or [2], which is a polyoxyalkylene group composed of propylene units.

[4] The dispersant for a hydraulic composition according to any one of [1] to [3], containing 0 to 10% by mass of polyalkylene glycol as the non-copolymerized structural unit (b).

[5] The dispersant for a hydraulic composition according to any one of [1] to [4], containing 5 to 50% by mass of polyalkylene glycol as the structural unit (c) that is not copolymerized.

(delete)

[ 6 ] The dispersant for hydraulic compositions according to any one of [1] to [ 5 ], wherein R ¹ in formula (1) is an allyl group.

[ 7 ] The dispersant for hydraulic compositions according to any one of [1] to [ 6 ], wherein R ⁴ in formula (2) is an allyl group.

[ 8 ] Any one of the above [1] to [ 7 ], wherein the mass ratio of formula (1) to formula (2) in the copolymer is 50/50 to 1/99. A dispersant for a hydraulic composition according to 1.

[ 9 ] The ratio Mw/Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn is 1.10 to 2.00 before copolymerization of the monomers of formula (1) and formula (2). The dispersant for a hydraulic composition according to any one of [1] to [ 8 ].

[ 10 ] The hydraulic composition according to any one of [1] to [ 9 ], wherein the content of unreacted structural units (a) in the dispersant for hydraulic compositions is 0.5% by mass or less. Dispersant.

[ 11 ] A hydraulic composition prepared using the hydraulic composition dispersant according to any one of [1] to [ 10 ].

[ 12 ] The hydraulic composition according to [ 11 ] above, which uses a binder containing silica fume.

The dispersant for a hydraulic composition of the present invention imparts high fluidity to the hydraulic composition even when the water/binder ratio is remarkably suppressed in order to obtain an ultra-high-strength cured body. Reduces viscosity and does not retard setting.

Embodiments of the present invention will be described below. The present invention is not limited to the following embodiments, and changes, modifications, and improvements can be made without departing from the scope of the invention.

1. Dispersant for Hydraulic Composition The dispersant for hydraulic composition of the present invention is a hydraulic composition containing water and a binder such that the water/binder ratio by mass is 0.05 or more and less than 0.20. It is a dispersant for hydraulic compositions used in products. The dispersant for hydraulic compositions contains a copolymer having a structural unit (a), a structural unit (b) and a structural unit (c), and the copolymer is polyethylene measured by gel permeation chromatography. Within the range of 5 to 50 times the mass average molecular weight of the monomer represented by the following formula (1), the mass average molecular weight of the monomer represented by the formula (2) in terms of glycol / polyethylene oxide It is in the range of 1.5 to 10 times.

Structural unit (a): a structural unit formed from an unsaturated carboxylic acid and/or a salt thereof, and 80 to 100 mol% of the unsaturated carboxylic acid and/or a salt thereof is (anhydrous) maleic acid, fumaric acid, or A structural unit formed from one or more salts selected from

（式（１）において、
Ｒ^１：炭素数３～５のアルケニル基
Ｒ^２Ｏ：炭素数２～３のオキシアルキレン基
Ｒ^３：水素原子、炭素数１～２２のアルキル基又は炭素数１～２２の脂肪族アシル基
ｍ：２～６５個のオキシエチレン単位で構成されたポリオキシエチレン基又は合計２～６５個のオキシエチレン単位とオキシプロピレン単位とで構成されたポリオキシアルキレン基の数） Structural unit (b): a structural unit formed from a monomer represented by the following formula (1)

(In formula (1),
R ¹ : alkenyl group having 3 to 5 carbon atoms R ² O: oxyalkylene group having 2 to 3 carbon atoms R ³ : hydrogen atom, alkyl group having 1 to 22 carbon atoms or aliphatic acyl group having 1 to 22 carbon atoms m : Number of polyoxyethylene groups composed of 2 to 65 oxyethylene units or polyoxyalkylene groups composed of a total of 2 to 65 oxyethylene units and oxypropylene units)

（式（２）において、
Ｒ^４：炭素数３～５のアルケニル基
Ｒ^５Ｏ：炭素数２～３のオキシアルキレン基
Ｒ^６：水素原子、炭素数１～２２のアルキル基又は炭素数１～２２の脂肪族アシル基
ｎ：３～６６個のオキシエチレン単位で構成されたポリオキシエチレン基又は合計３～６６個のオキシエチレン単位とオキシプロピレン単位とで構成されたポリオキシアルキレン基の数）
ただし、式（１）と式（２）において ｎ＞ｍ
以下、構成単位について詳しく説明する。 Structural unit (c): a structural unit formed from a monomer represented by the following formula (2)

(In formula (2),
R ⁴ : alkenyl group having 3 to 5 carbon atoms R ⁵ O: oxyalkylene group having 2 to 3 carbon atoms R ⁶ : hydrogen atom, alkyl group having 1 to 22 carbon atoms or aliphatic acyl group having 1 to 22 carbon atoms n : Number of polyoxyethylene groups composed of 3 to 66 oxyethylene units or polyoxyalkylene groups composed of a total of 3 to 66 oxyethylene units and oxypropylene units)
However, in formulas (1) and (2), n>m
The structural units will be described in detail below.

1-1. Structural unit (a)
Examples of the unsaturated carboxylic acid or its salt as the structural unit (a) include (anhydrous) maleic acid, fumaric acid, (meth)acrylic acid, itaconic acid, citraconic acid, maleic acid monoalkyl ester, fumaric acid monoalkyl ester, and itaconic acid. acid monoalkyl esters, citraconic acid monoalkyl esters, salts thereof, and the like. Among the structural units (a), 80 mol % or more and 100 mol % or less are structural units formed from one or more selected from (anhydrous) maleic acid, fumaric acid and salts thereof.

The structural unit (a) includes 1) a structural unit formed from (anhydride) maleic acid, 2) a structural unit formed from a maleate, and 3) a structural unit composed of both 1) and 2) above. mentioned. Here, the type of maleate salt is not particularly limited, but alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts and magnesium salts, ammonium salts, and diethanolamine. salts, amine salts such as triethanolamine salts, and the like. Of these maleates, sodium salts and calcium salts are preferred.

Examples of the structural unit (a) include 1) a structural unit formed from fumaric acid, 2) a structural unit formed from a fumarate salt, and 3) those composed of both the above 1) and 2). Here, the salt of fumarate is not particularly limited in kind, but alkali metal salts such as sodium salts and potassium salts, alkaline earth metal salts such as calcium salts and magnesium salts, ammonium salts, and diethanolamine. salts, amine salts such as triethanolamine salts, and the like. Among them, sodium salt and calcium salt are preferable as the salt of fumarate.

The structural unit (a) may contain a mixture of (anhydride) maleic acid, fumaric acid and salts thereof.

1-2. Structural unit (b) and structural unit (c)
Structural unit (b) is a structural unit formed from a monomer represented by formula (1), and structural unit (c) is a structural unit formed from a monomer represented by formula (2). However, structural unit (b) and structural unit (c) will be explained.

In the formula (1), the structural unit (b) is (R ² O) _m is a polyoxyethylene group composed of oxyethylene units in which m is 2 to 99, or an oxyethylene group in which m is 2 to 99 in total. It can be a polyoxyalkylene group composed of ethylene units and oxypropylene units, but in the present invention, a polyoxyethylene group composed of 2 to 65 oxyethylene units or a total of 2 to 65 It is a polyoxyalkylene group composed of oxyethylene units and oxypropylene units. More preferably, m is a polyoxyethylene group composed of 5 to 65 oxyethylene units, or a polyoxyalkylene group composed of 5 to 65 oxyethylene units and oxypropylene units in total m. .

Structural unit (c) is represented by formula (2), wherein (R ⁵ O) _n is a polyoxyethylene group composed of oxyethylene units in which n is 3 to 100, or an oxyethylene group in which n is 3 to 100 in total. It can be a polyoxyalkylene group composed of ethylene units and oxypropylene units, but in the present invention, a polyoxyethylene group composed of 3 to 66 oxyethylene units or a total n of 3 to It is a polyoxyalkylene group composed of 66 oxyethylene units and oxypropylene units. More preferably, n is a polyoxyethylene group composed of 6 to 66 oxyethylene units, or a total n is a polyoxyalkylene group composed of 6 to 66 oxyethylene units and oxypropylene units. .

R ¹ in formula (1) and R ⁴ in formula (2) are isopropenyl group, allyl group, methallyl group, 3-butenyl group, 2-methyl-1-butenyl group and 3-methyl-1-butenyl group. , 2-methyl-3-butenyl group, 3-methyl-3-butenyl group and other alkenyl groups having 3 to 5 carbon atoms. Among them, R ¹ and R ⁴ are preferably allyl groups.

Examples of R ³ in formula (1) and R ⁶ in formula (2) include 1) a hydrogen atom, 2) an alkyl group having 1 to 22 carbon atoms, and 3) an aliphatic acyl group having 1 to 22 carbon atoms. . Examples of alkyl groups having 1 to 22 carbon atoms include methyl group, ethyl group, butyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, nonadecyl group, eicosyl group, heneicosyl group, docosyl group, 2-methyl-pentyl group, 2-ethyl-hexyl group, 2-propyl-heptyl group, 2-butyl-octyl group, 2-pentyl- nonyl group, 2-hexyl-decyl group, 2-heptyl-undecyl group, 2-octyl-dodecyl group, 2-nonyl-tridecyl group and the like. Examples of aliphatic acyl groups having 1 to 22 carbon atoms include formyl, acetyl, propanoyl, butanoyl, hexanoyl, heptanoyl, octanoyl, nonanoyl, decanoyl, hexadecanoyl, and octadecanoyl groups. , hexadecenoyl group, eicosenoyl group, octadecenoyl group and the like. Among them, R ³ and R ⁶ are preferably a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably a hydrogen atom or a methyl group.

Specific examples of the monomers represented by formulas (1) and (2) described above include α-allyl-ω-methoxy-(poly)oxyethylene, α-allyl-ω-methoxy-(poly)oxy Ethylene (poly)oxypropylene, α-allyl-ω-acetyl-(poly)oxyethylene, α-allyl-ω-acetyl-(poly)oxyethylene (poly)oxypropylene, α-allyl-ω-hydroxy-(poly ) oxyethylene, α-allyl-ω-hydroxy-(poly)oxyethylene (poly)oxypropylene and the like. Structural unit (b) and structural unit (c) are structural units each formed from one or more of these monomers.

In the dispersant for hydraulic compositions, the weight ratio of formula (1) and formula (2) in the copolymer, formula (1)/formula (2), is preferably from 50/50 to 1/99. More preferably, it is 40/60 to 5/95.

The dispersant for hydraulic composition has a ratio Mw/Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 1.10 before copolymerization of the monomers of formula (1) and formula (2). ~2.00 is preferred. More preferably, it is between 1.10 and 1.60. If the Mw/Mn ratio is too large, the effect of reducing viscosity, which is the effect of the present invention, will be difficult to achieve.

Also, the above copolymer may contain other polymerizable monomers. Other polymerizable monomers include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, and butyl (meth)acrylate, Dialkyl esters of bifunctional unsaturated carboxylic acids such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, dialkyl maleate, dialkyl fumarate, dialkyl itaconate, acrylamide, N,N-dimethyl (Meth)acrylamide, styrene, and the like.

The copolymer contained in the dispersant for a hydraulic composition of the present invention preferably contains 1 to 49% by mass of a structure derived from an unsaturated carboxylic acid such as maleic acid or fumaric acid, and has the formula (1) A structure containing 1 to 49% by mass of the structure derived from the monomer shown and 2 to 98% by mass (total 100% by mass) of the structure derived from the monomer represented by formula (2) Preferably, the copolymer contains 1 to 20% by mass of a structure derived from an unsaturated carboxylic acid system, 2 to 40% by mass of a structure derived from a monomer represented by formula (1), and a unit represented by formula (2) More preferably, it contains 40 to 97% by mass (total 100% by mass) of the structure derived from the polymer.

1-3. Weight-average molecular weight The copolymer has a weight-average molecular weight in terms of polyethylene glycol/polyethylene oxide measured by gel permeation chromatography in the range of 5 to 50 times the weight-average molecular weight of the monomer represented by formula (1). and can be in the range of 1.5 to 10 times the mass average molecular weight of the monomer represented by formula (2). Within this range, the monomer derived from the unsaturated carboxylic acid and the formulas (1) and (2) are copolymerized in an appropriate proportion to exhibit the effects of the present invention. In order to obtain even better effects, in the present invention, the weight average molecular weight of the copolymer is in the range of 10 to 32.5 times the weight average molecular weight of the monomer represented by formula (1), preferably 10 to 30. 1.5 to 7.5 times the weight average molecular weight of the monomer of formula (2), more preferably 2 to 7.5 times.

Further, the weight average molecular weight of the copolymer in terms of polyethylene glycol/polyethylene oxide is Mw 5,000 to 20,000 . More preferably, it is 6,000 to 15,000. If it is less than this range, the dispersibility will be insufficient and the addition rate will be excessive, and if it is more than this range, it will lead to an increase in viscosity.

1-4. Method for Synthesizing Copolymer and Method for Preparing Dispersant for Hydraulic Composition The copolymer contained in the dispersant for hydraulic composition of the present invention can be synthesized by a known method. For example, the methods described in JP-A-58-32051 and JP-A-4-149056 can be mentioned. More specifically, first, predetermined amounts of the monomers represented by the formulas (1) and (2) and water were charged into a reaction vessel, and the inside of the reaction vessel was replaced with nitrogen while stirring. Heat to ~95°C. Next, an aqueous solution prepared by dissolving a predetermined amount of maleic anhydride (maleic anhydride is described as an example, but fumaric acid is the same) and a radical polymerization initiator in water is added over about 2 hours. Further, an aqueous solution of a radical polymerization initiator is added, and a polymerization reaction is carried out at 80 to 95° C. for about 2 hours to obtain an aqueous solution of a maleic acid copolymer. The type of the radical polymerization initiator used here is not particularly limited as long as it decomposes at the polymerization reaction temperature to generate radicals, but it is preferable to use a water-soluble radical initiator. Such water-soluble radical initiators include persulfates such as potassium persulfate and ammonium persulfate, hydrogen peroxide, 2,2′-azobis(2-amidinopropane) dihydrochloride and the like. These can also be used as redox initiators in combination with reducing substances such as sulfites and L-ascorbic acid, as well as amines and the like. Chain transfer agents such as 2-mercaptoethanol, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thioglycolic acid, and thioglycerin are used to keep the mass average molecular weight of the resulting maleic acid copolymer within the desired range. can also be used. A maleic acid copolymer can generally be synthesized by the method described above. An aqueous solution having a total concentration of the three components of 10 to 80% by mass was prepared, the inside of the reaction vessel was replaced with nitrogen while stirring, heated to 50 to 70°C in a nitrogen atmosphere, and then the radical polymerization initiator was added. A method of adding an aqueous solution to a reaction vessel and carrying out a polymerization reaction is preferred.

When the dispersant for a hydraulic composition of the present invention comprises a maleic acid copolymer and the monomers represented by the formulas (1) and (2), the method for preparing the same includes 1) maleic acid copolymer A method of leaving the monomers represented by formulas (1) and (2) in the synthesis system when synthesizing the coalescence, 2) maleic acid copolymer, formula (1), and formula (2) 3) A method in which the monomer represented by ) is separately prepared and both are blended; and the like, but the preparation method of 1) above is preferred. As the preparation method of 1) above, one or two or more selected from maleic anhydride, maleic acid and maleic acid salts as raw materials, and the monomers represented by formulas (1) and (2) Using one or two or more of each, after dissolving each predetermined amount in water to make an aqueous solution, a radical polymerization initiator is added to this under a nitrogen atmosphere, and radicals are added in an aqueous system heated to 50 to 70 ° C. A copolymerization reaction is carried out for a predetermined period of time to obtain a reaction mixture comprising a predetermined ratio of maleic acid copolymer and monomers represented by formulas (1) and (2). As a method for determining the time for the radical copolymerization reaction, 1) a part of the reaction mixture is sampled from the reaction system at regular intervals, and a rapid analysis method such as gel permeation chromatography (GPC) or high performance liquid chromatography is performed. Calculate the ratio of the produced maleic acid copolymer to the remaining monomers represented by the formulas (1) and (2), the weight average molecular weight of the maleic acid copolymer, etc., and radical copolymerization from the obtained values. 2) the ratio of the generated maleic acid copolymer and the remaining monomers represented by the formulas (1) and (2) to the radical copolymerization reaction time; For example, the relationship between the mass-average molecular weight of the maleic acid copolymer is obtained and the radical copolymerization reaction is stopped at a desired time. preferable. The same applies when fumaric acid is included.

The dispersant for a hydraulic composition of the present invention contains the copolymer as described above, preferably at least 30% by mass of the copolymer, more preferably at least 50% by mass of the copolymer. It is something to do. Structural units (a), structural units (b) and structural units (c) that are not copolymerized may remain. After copolymerization in an aqueous solvent, it can be used as a dispersant for hydraulic compositions without a purification step, resulting in a reduction in man-hours.

At this time, in the hydraulic composition dispersant, the content of the non-copolymerized structural unit (a) (that is, the unreacted structural unit (a)) is 0.5 mass in the hydraulic composition dispersant. % or less. More preferably, it is 0.3% by mass or less. If the non-copolymerized structural unit (a) is more than 0.5% by mass, the retardation of setting increases, and the time to reach the strength required to release the mold becomes longer, leading to a decrease in work efficiency. Further, in the dispersant for the hydraulic composition, the polyalkylene glycol of the structural unit (b) that is not copolymerized is preferably 0 to 10% by mass, and the polyalkylene glycol of the structural unit (c) that is not copolymerized Glycol is preferably 5 to 50% by weight. If it deviates from this range, the mass-average molecular weight of the obtained copolymer may not be within the appropriate range, and the viscosity may increase.

2. Hydraulic Composition Next, the hydraulic composition of the present invention will be described. The hydraulic composition of the present invention is a hydraulic composition such as cement paste, mortar and concrete prepared using the dispersant for hydraulic compositions of the present invention as described above. Although the hydraulic composition of the present invention uses at least cement as a binder, it also includes a composition using a fine powder admixture as a part of the binder. Examples of such cement include: 1) various Portland cements such as ordinary Portland cement, high-early-strength Portland cement, moderate-heat Portland cement, and low-heat Portland cement; 2) various mixed cements such as blast furnace cement, fly ash cement, and silica fume cement; and 3) alumina. Cement etc. are mentioned. Examples of the fine powder admixture include fine powder of blast furnace slag, silica fume, fly ash, and the like. As a binding material, silica fume cement or one using various cements and silica fume is preferable. As fine aggregates, coarse aggregates, and various cement admixtures other than the dispersant for the hydraulic composition of the present invention, known ones can be applied.

In the hydraulic composition of the present invention, the water/binder ratio is preferably 0.05 to 0.20, more preferably 0.07 to 0.18, and more preferably 0.08 to 0.16. is particularly preferred. In the case of preparing a hydraulic composition with a remarkably reduced water/binder ratio, the dispersant for hydraulic compositions of the present invention is highly effective.

The amount of the dispersant for a hydraulic composition of the present invention added to the hydraulic composition of the present invention can be appropriately adjusted within the range of solving the problems of the present invention. It is preferably 4.0 parts by mass, more preferably 0.05 to 2.0 parts by mass. The hydraulic composition dispersant of the present invention is usually added together with kneading water when preparing the hydraulic composition of the present invention.

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

1. Test category 1 (preparation of dispersant for hydraulic composition)
Table 1 shows the dispersants for hydraulic compositions of Examples 1 to 10 and Comparative Examples 1 to 3. The admixture is an aqueous solution of a dispersant for hydraulic compositions. The preparation method will be described in detail below.

Example 1 (Preparation of Admixture PC-1)
414.8 g distilled water, 29.4 g maleic anhydride, 23.2 g α-allyl-ω-methoxy-poly(n=11) oxyethylene, and α-allyl-ω-methoxy-poly(n=33) oxyethylene 236.9 g was charged into a reaction vessel and dissolved uniformly with stirring, after which the atmosphere was replaced with nitrogen. The temperature of the reaction system was kept at 70° C. in a hot water bath, and an aqueous solution prepared by dissolving 5.2 g of sodium persulfate in 17.6 g of distilled water was added to initiate a radical copolymerization reaction. After 1 hour, an aqueous solution prepared by dissolving 5.2 g of sodium persulfate in 17.6 g of distilled water was added, and the mixture was kept at 70° C. for 3 hours to carry out a radical copolymerization reaction. By adjusting the reaction system to a concentration of 30% active ingredient with distilled water, the copolymer and unreacted α-allyl-ω-methoxy-poly(n=11) oxyethylene, α-allyl-ω-methoxy- An admixture (PC-1), which is an aqueous solution of a dispersant for a hydraulic composition containing poly(n=33)oxyethylene and maleic acid, was obtained.

Examples 2 to 9, Comparative Examples 1 and 3
In the same manner as in Example 1, the monomers listed in Table 1 were reacted to obtain admixtures (PC-2) to (PC-9), which are aqueous solutions of hydraulic composition dispersants having a concentration of 30%, ( R-1) and (R-3) were obtained.

Example 10 (Production of Admixture PC-10)
207.4 g of distilled water and 25.8 g of maleic anhydride were charged into a reaction vessel and uniformly dissolved with stirring, after which the atmosphere was replaced with nitrogen. The temperature of the reaction system was maintained at 70° C. with a warm water bath, and α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=9)oxyethylene 41.6 g and α-(3-methyl- An aqueous solution prepared by dissolving 222.0 g of 3-butenyl)-ω-hydroxy-poly(n=53)oxyethylene in 207.4 g of distilled water was added dropwise to the reaction system over 2 hours. At the same time, an aqueous solution prepared by dissolving 10.5 g of sodium persulfate in 35.2 g of distilled water was added dropwise over 3 hours to carry out a radical copolymerization reaction. After dropping all the aqueous solutions, the reaction temperature was maintained for 1 hour, and then the reaction system was adjusted with distilled water to an active ingredient concentration of 30%. -butenyl)-ω-hydroxy-poly(n=9)oxyethylene, α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53)oxyethylene, and hydraulic containing maleic acid An admixture (PC-10), which is an aqueous solution of the dispersant for the composition, was obtained.

Comparative example 2
In the same manner as in Example 10, the monomers shown in Table 1 were reacted to obtain an admixture (R-2), which was an aqueous solution having a concentration of 30% of a dispersant for hydraulic composition.

Table 1 shows the mass ratio and molecular weight of each monomer, and the degree of dispersion as a ratio of mass average molecular weight (Mw)/number average molecular weight (Mn) as an index of dispersion.

In Table 1,
MA: maleic anhydride FA: fumaric acid MS-1: α-allyl-ω-methoxy-poly(n=11) oxyethylene MS-2: α-allyl-ω-hydroxy-poly(n=16) oxyethylene MS -3: α-allyl-ω-hydroxy-poly (n = 9) oxyethylene MS-4: α-allyl-ω-methoxy-poly (n = 8) oxyethylene MS-5: α-methallyl-ω-hydroxy - Poly(n=16) oxyethylene MS-6: α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=9) oxyethylene ML-1: α-allyl-ω-methoxy-poly (n=33) oxyethylene ML-2: α-allyl-ω-hydroxy-poly(n=33) oxyethylene ML-3: α-allyl-ω-hydroxy-poly(n=53) oxyethylene ML-4 : α-methallyl-ω-hydroxy-poly(n=53) oxyethylene ML-5: α-(3-methyl-3-butenyl)-ω-hydroxy-poly(n=53) oxyethylene In addition, the above MS- n in 1 to MS-6 corresponds to m in formula (1).

2. Test category 2 (analysis of monomers and admixtures)
The monomers and admixtures of Examples 1-10 and Comparative Examples 1-3 were analyzed as follows.

-Molecular weight distribution of the monomer (a mixture of the monomer represented by the formula (1) and the monomer represented by the formula (2))
The molecular weight distribution (Mw/Mn) of the mixture of the monomer represented by formula (1) and the monomer represented by formula (2) used for copolymerization was measured by GPC (gel permeation chromatography). and tetrahydrofuran was used as an eluent, and the polystyrene equivalent molecular weight was obtained.
<Measurement conditions>
Apparatus: Tosoh HLC-8320GPC
Column: TSKgel Super H4000, H3000, H2000
Detector: differential refractometer (RI)
Eluent: Tetrahydrofuran Flow rate: 0.5 mL/min Column temperature: 40°C
Sample concentration: Eluent solution with an active ingredient concentration of 0.5% by mass Injection volume: 25 μL
Reference material: Tosoh polystyrene

・Unreacted maleic acid (MA), fumaric acid (FA)
The remaining amounts of unreacted maleic acid and unreacted fumaric acid were measured by ion chromatography.
<Measurement conditions>
Apparatus: Dionex ICS-2100 manufactured by Thermo Fisher Scientific
Column: Thermo Fisher Scientific Dionex IonPac AS11 (4 × 250 mm SB column)
Detector: electrical conductivity Eluent: 5 mM aqueous potassium hydroxide solution Flow rate: 2.0 mL/min Column temperature: 35°C
Sample concentration: Eluent solution with an active ingredient concentration of 0.05% by mass Injection volume: 25 μL

- Mass average molecular weight (Mw) of unreacted monomers and copolymers of structural units (b) and (c)
The amount of unreacted monomers of the structural units (b) and (c) and the mass average molecular weight (Mw) of the copolymer were measured by gel permeation chromatography under the following measurement conditions.
<Measurement conditions>
Apparatus: Shodex GPC-101
Column: Showa Denko OHpak SB-G + SB-806M HQ + SB-806M HQ
Detector: differential refractometer (RI)
Eluent: 50 mM aqueous sodium nitrate solution Flow rate: 0.7 mL/min Column temperature: 40°C
Sample concentration: Eluent solution with active ingredient concentration of 0.5% by mass Standard substances: Polyethylene oxide and polyethylene glycol manufactured by Agilent Injection volume: 25 μm

Table 2 shows the analytical results of the hydraulic composition dispersants, which are the active ingredients of the admixtures of Examples 1 to 10 and Comparative Examples 1 to 3, which were prepared from the structural units shown in Table 1.

3. Test category 3 (preparation and evaluation of hydraulic composition)
Hydraulic compositions comprising the admixtures of Examples 1 to 10 and Comparative Examples 1 to 3, binders, water, fine aggregates and coarse aggregates were prepared. Hydraulic compositions were prepared as follows under the formulation conditions shown in Table 3 in a constant temperature room at 20° C. and 80% humidity. Silica fume cement (manufactured by Ube-Mitsubishi Cement Co., Ltd., specific gravity = 3.08) and fine aggregate (Oigawa water system sand, specific gravity = 2.58) were sequentially added to a 55 L forced kneading twin-screw mixer, and after empty kneading for 15 seconds, A dispersant for hydraulic compositions is added so that the target slump flow is 65±5 cm and the air content is 3% or less, and a polyether-based dispersant is added so that the ratio is 0.01 part by weight per 100 parts by weight of the binder. A foaming agent (trade name AFK-2 manufactured by Takemoto Yushi Co., Ltd.) was added together with kneading water and kneaded for 5 minutes. Further, coarse aggregate (crushed stone from Okazaki, specific gravity = 2.68) was added, kneaded for 2 minutes, allowed to stand for 5 minutes, kneaded for 30 seconds, and discharged. A concrete test was performed using the prepared hydraulic composition.

・Addition rate (%) of dispersant for hydraulic composition: mass addition rate (% by mass) of the components of the admixture, which is an aqueous solution, excluding water, relative to the binder
Comparative Example 6 in Table 4 is the result of adding 0.30% by mass and 0.10% by mass of R-1 and R-3, respectively.

· Slump flow Immediately after kneading and after standing for 60 minutes, the hydraulic composition was sufficiently turned back before measurement, and measured 3 minutes after pulling out the slump cone in accordance with JIS-A1150.

- Air content Immediately after kneading and after standing for 60 minutes, the hydraulic composition was sufficiently turned over before measurement, and then measured according to JIS-A1128.

O funnel flow down time Immediately after kneading and after standing for 60 minutes, the hydraulic composition was sufficiently turned over before measurement, and then measured using an O funnel in accordance with JSCE-F512.

- Setting time test: Initial setting time, final setting time In accordance with JIS A 1147, the concrete of each example after concrete kneading was sieved, the mortar portion was sampled, and the initial setting time and final setting time of the concrete were measured.

Compressive strength The ultra-high-strength concrete composition of each example is filled in a steel form in a constant temperature room of 20 ° C. x 80% RH, hardened, demolded after 2 days of material age, and placed in a curing tank with a water temperature of 20 ° C. It was cured until the material age was 28 days. Measurements were made in accordance with JIS-A1108 for the 28-day-old cured product.

As shown in Table 4, Examples 11 to 20 had a shorter O-funnel flow-down time and higher fluidity than Comparative Examples 4 to 6. Moreover, in Examples 11 to 20, compared with Comparative Examples 4 to 6, the starting time and finishing time were not delayed, and the coagulation was not delayed. The compressive strength of Examples 11-20 was also sufficiently higher than that of Comparative Examples 4-6.

The dispersant for hydraulic composition of the present invention can be used as a dispersant when preparing a hydraulic composition. INDUSTRIAL APPLICABILITY The hydraulic composition of the present invention can be beneficially used in building members for various buildings and building members.

Claims (12)

A hydraulic composition dispersant used in a hydraulic composition containing water and a binder such that the water/binder ratio by mass is 0.05 or more and less than 0.20,
A copolymer having a structural unit (a), a structural unit (b) and a structural unit (c) and having a weight average molecular weight in terms of polyethylene glycol/polyethylene oxide of Mw 5000 to 20000 ,
In addition, the copolymer has a weight average molecular weight in terms of polyethylene glycol/polyethylene oxide measured by gel permeation chromatography that is 10 to 32.5 times the weight average molecular weight of the monomer represented by the following formula (1). and 1.5 to 7.5 times the weight average molecular weight of the monomer represented by formula (2).
Structural unit (a): a structural unit formed from an unsaturated carboxylic acid and/or a salt thereof, and 80 to 100 mol% of the unsaturated carboxylic acid and/or a salt thereof is (anhydrous) maleic acid, fumaric acid, or Structural unit (b): a structural unit formed from a monomer represented by the following formula (1)

(In formula (1),
R ¹ : alkenyl group having 3 to 5 carbon atoms R ² O: oxyalkylene group having 2 to 3 carbon atoms R ³ : hydrogen atom, alkyl group having 1 to 22 carbon atoms or aliphatic acyl group having 1 to 22 carbon atoms m : Number of polyoxyethylene groups composed of 2 to 65 oxyethylene units or polyoxyalkylene groups composed of a total of 2 to 65 oxyethylene units and oxypropylene units)
Structural unit (c): a structural unit formed from a monomer represented by the following formula (2)

(In formula (2),
R ⁴ : alkenyl group having 3 to 5 carbon atoms R ⁵ O: oxyalkylene group having 2 to 3 carbon atoms R ⁶ : hydrogen atom, alkyl group having 1 to 22 carbon atoms or aliphatic acyl group having 1 to 22 carbon atoms n : The number of polyoxyethylene groups composed of 3 to 66 oxyethylene units or polyoxyalkylene groups composed of oxyethylene units and oxypropylene units with a total n of 3 to 66)
However, in formulas (1) and (2), n>m In formula (1), (R ² O) _m is a polyoxyethylene group composed of 5 to 65 oxyethylene units, or a total of 5 to 65 oxyethylene units and oxypropylene units. The dispersant for a hydraulic composition according to claim 1, which is a polyoxyalkylene group composed of In formula (2), (R ⁵ O) _n is a polyoxyethylene group composed of 6 to 66 oxyethylene units, or a total of 6 to 66 oxyethylene units and oxypropylene units. The dispersant for a hydraulic composition according to claim 1 or 2, which is a polyoxyalkylene group composed of. 4. The dispersant for hydraulic composition according to any one of claims 1 to 3, comprising 0 to 10% by mass of polyalkylene glycol as the non-copolymerized structural unit (b). 5. The dispersant for hydraulic composition according to any one of claims 1 to 4, comprising 5 to 50% by mass of polyalkylene glycol as the non-copolymerized structural unit (c). 6. The dispersant for hydraulic compositions according to any one of claims 1 to 5 , wherein R ¹ in formula (1) is an allyl group. The dispersant for hydraulic compositions according to any one of claims 1 to 6 , wherein R ⁴ in formula (2) is an allyl group. The formula (1)/formula (2) of the mass ratio of formula (1) and formula (2) in the copolymer is 50/50 to 1/99, according to any one of claims 1 to 7 . Dispersant for hydraulic compositions. The ratio Mw/Mn of the weight average molecular weight Mw to the number average molecular weight Mn is from 1.10 to 2.00 before copolymerization of the monomers of formula (1) and formula (2). 9. The dispersant for a hydraulic composition according to any one of 8 . 10. The dispersant for hydraulic compositions according to any one of claims 1 to 9 , wherein the content of unreacted structural units (a) in the dispersant for hydraulic compositions is 0.5% by mass or less. A hydraulic composition prepared using the hydraulic composition dispersant according to any one of claims 1 to 10 . 12. The hydraulic composition according to claim 11 , wherein a binder containing silica fume is used.