JP6711596B2 - Grinding aid for hydraulic powder - Google Patents

Description

The present invention relates to a grinding aid for hydraulic powder.

In the hydraulic composition, from the viewpoint of workability in casting, it is necessary to enhance the fluidity of the hydraulic composition before setting. A dispersant for a hydraulic composition is a chemical admixture used to disperse cement particles to reduce the amount of unit water required to obtain a required slump and improve workability of the hydraulic composition. Is. However, when the amount of the dispersant is increased to increase the fluidity of the hydraulic composition, the retardation of setting of the hydraulic composition tends to be promoted, and other additives are added to reduce the amount of the dispersant. It is desirable to use them together.

Further, in Patent Documents 1 and 2, an acrylic polymer is added to a clinker as a dispersant or a separation reducing agent in order to improve dispersibility or reduce material separation, and crushed to obtain a hydraulic powder. A manufacturing method for obtaining (cement) is disclosed. However, the hydraulic composition using the hydraulic powder obtained by these manufacturing methods, although the desired effect is obtained, the dispersant species when preparing the hydraulic composition is limited, etc., This limits the use of hydraulic compositions. Therefore, the hydraulic powder to which the acrylic polymer is added has poor versatility.

Generally, hydraulic powder (cement) is sold as a general-purpose product on the market, and thus it is difficult to specify a dispersant species when preparing a hydraulic composition thereafter. Therefore, it is desired that the hydraulic powder (cement) is not limited to the kind of dispersant necessary for improving the initial fluidity when the hydraulic composition is prepared, that is, the initial fluidity.

Hydraulic compositions to which an acrylic polymer is added are disclosed in the following patent documents in addition to the above-mentioned patent documents.
Patent Document 3 discloses a concrete composition to which sodium polyacrylate is added as a water-soluble polymer at the time of kneading.
Patent Document 4 discloses a self-compacting concrete composition to which sodium polyacrylate is added as a water-soluble polymer at the time of kneading.
Patent Document 5 discloses a high-fluidity concrete composition to which sodium polyacrylate is added as an acrylic polymer derivative at the time of kneading.

JP, 7-126051, A JP, 6-64951, A JP-A-6-127987 JP, 6-115995, A JP, 10-158046, A

The present invention provides a grinding aid for hydraulic powder, which improves the fluidity of the hydraulic composition when used in combination with a dispersant.

The present inventors add a polyacrylic acid salt having a specific molecular weight at the time of pulverizing a raw material for hydraulic powder so that the hydraulic composition can be added regardless of the kind of the dispersant added at the time of kneading the hydraulic composition. It was found that the initial fluidity of the product can be improved.

That is, the present invention is one or more polyacrylic acid salts selected from a polyacrylic acid alkali metal salt having a weight average molecular weight of 10,000 or more and 45,000 or less and a polyacrylic acid alkaline earth metal salt having a weight average molecular weight of 10,000 or more and 45,000 or less. And a grinding aid for hydraulic powder.

According to the present invention, there is provided a grinding aid for hydraulic powder, which improves the fluidity of the hydraulic composition when used in combination with a dispersant.
As a result, the amount of dispersant used to obtain a desired fluidity can be reduced, and retardation of setting of the hydraulic composition due to use of an excessive amount of dispersant can be suppressed.

<Crushing aid for hydraulic powder>
The crushing aid for hydraulic powder of the present invention is an aid used for crushing the raw material for hydraulic powder, and the crushing scale does not matter, such as the degree of particle size change due to crushing. For example, a grinding aid to be added when the clinker, which is the raw material of hydraulic powder, is crushed by mechanical force using a ball mill or a vertical mill, coarse particles after pre-crushing the clinker are ball mills or vertical mills, etc. By a mechanical force using a ball mill, a vertical mill, etc. Includes a grinding aid that is added during additional grinding to increase fineness to fine particles.
In the present invention, the raw material for hydraulic powder includes clinker and particulate hydraulic powder.

The grinding aid for hydraulic powder of the present invention is selected from polyacrylic acid alkali metal salts having a weight average molecular weight of 10,000 or more and 45,000 or less and polyacrylic acid alkaline earth metal salts having a weight average molecular weight of 10,000 or more and 45,000 or less. Contains one or more polyacrylates.

The polyacrylic acid salt is preferably selected from polyacrylic acid alkali metal salts having a weight average molecular weight of 10,000 or more and 45,000 or less, from the viewpoint of fluidity after kneading and preparing hydraulic powder, water and aggregate. And one or more compounds described above. The polyacrylic acid salt is preferably a polyacrylic acid alkali metal salt having a weight average molecular weight of 10,000 or more and 45,000 or less, from the viewpoint of fluidity after kneading and preparing hydraulic powder, water and aggregate. One or more compounds selected. The alkali metal salt is preferably one or more selected from sodium salt and potassium salt, and more preferably sodium salt. The degree of neutralization of the polyacrylic acid salt is preferably 0.5 to 1.

The weight average molecular weight of the polyacrylic acid salt is 10,000 or more, preferably 20,000 or more, more preferably 30,000 or more, further preferably from the viewpoint of fluidity after kneading and preparing a hydraulic powder, water and an aggregate. Is 35,000 or more, and from the same viewpoint, it is 45,000 or less, preferably 43,000 or less, more preferably 40,000 or less, still more preferably 39000 or less.

The weight average molecular weight of the polyacrylic acid salt is based on the gel permeation chromatography (GPC) method (polyethylene glycol conversion), and specific conditions are as follows.
*Gel permeation chromatography conditions Device: GPC (HLC-8320GPC) Tosoh Corporation Column: G4000PWXL+G2500PWXL (Tosoh Corporation)
Eluent: 0.2 M phosphate buffer/CH ₃ CN=9/1
Flow rate: 1.0 mL/min
Column temperature: 40°C
Detection: RI
Sample size: 0.2mg/mL
Standard substance: Polyethylene glycol equivalent (monodisperse polyethylene glycol with molecular weight 87500, 250,000, 145,000, 46,000, 24,000)

The weight average molecular weight of the polyacrylic acid salt as polyacrylic acid is 5,000 or more, preferably 10,000 or more, more preferably from the viewpoint of fluidity after kneading and preparing a hydraulic powder, water and an aggregate. It is 20,000 or more, more preferably 25,000 or more, and from the same viewpoint, it is 35,000 or less, preferably 33,000 or less, more preferably 31,000 or less, still more preferably 30,000 or less.
The weight average molecular weight of polyacrylic acid can be converted from the weight average molecular weight of the polyacrylic acid salt when the degree of neutralization and the salt are known.
The weight average molecular weight of polyacrylic acid is, for example, the weight average molecular weight as a polyacrylic acid salt is measured by GPC under the above conditions, and the type and amount of the counter ion are separately measured by ion chromatography to determine the type of the counter ion. And the amount of polyacrylate can be estimated, and the molecular weight of the polyionate can be calculated by subtracting the molecular weight of the counterion.

The polyacrylic acid salt can be produced, for example, by the method described in JP-A No. 62-121705. For example, a polyacrylic acid salt is produced by charging polyacrylic acid and water, raising the temperature to a predetermined temperature, reacting in the presence of a polymerization initiator or a chain transfer agent, aging, and then neutralizing. be able to.

Examples of the polyacrylate include Poiz series manufactured by Kao Corporation, Acumer series manufactured by The Dow Chemical Company, Acusol series, Aqualic series manufactured by Nippon Shokubai Co., Ltd., Aron series manufactured by Toagosei Co., Ltd., Jurymer series, manufactured by BASF. Commercially available reagents such as Sokalan PA series can also be used.

The grinding aid for hydraulic powder of the present invention may be added as a grinding aid when grinding the clinker, which is a raw material for hydraulic powder, by mechanical force using a ball mill, a vertical mill, or the like. The coarse particles after the pre-pulverization may be added as a finishing pulverization aid when the fineness is increased to fine particles by using a mechanical force using a ball mill or a vertical mill. Further, fine particles of the hydraulic powder may be added as a grinding aid for additional grinding when the fineness of the particles is increased by using mechanical force using a ball mill or a vertical mill.

The grinding aid for hydraulic powder of the present invention can improve the fluidity of a hydraulic composition when used in combination with a dispersant.
The mechanism of such effect expression is not necessarily clarified, but it is presumed as follows.
Usually, when kneading a hydraulic powder and water and a dispersant when preparing a hydraulic composition, the dispersant is adsorbed on the surface of the hydraulic powder, and crystal growth is caused by the reaction between the hydraulic powder and water. Proceed at the same time. The dispersant adsorbed on the surface of the hydraulic powder with the passage of time is buried in the crystal due to crystal growth, so that the dispersing action is difficult to be exhibited.

On the other hand, when the polyacrylic acid salt having a specific molecular weight of the present invention is used at the time of pulverizing the hydraulic powder, when the dispersant and the hydraulic powder are kneaded, the polyacrylic acid salt is already present at the adsorption site of the dispersant. It is presumed that the presence of the dispersant reduces the amount of the dispersant to be buried, and as a result, suppresses the deterioration of the fluidity and exhibits high dispersibility.

Further, conventionally known polyacrylate having a large molecular weight is used as a thickener for hydraulic compositions, and under a highly alkaline condition such as cement, a general polycarboxylic acid dispersant is used. Unlike, it does not contribute to liquidity.
As in the present invention, by defining the molecular weight range of the polyacrylic acid salt as described above, it is possible to suppress the conventionally known thickening action. Therefore, the hydraulic powder to which the specific polyacrylic acid salt of the present invention is added can be handled in the same manner as ordinary hydraulic powder (cement) generally sold in the market.

The step of adding a grinding aid and crushing includes, for example, a step of crushing a lump of clinker into a powder, a finishing crushing step of crushing coarse particles after precrushing the clinker into a fine particle, a powdery state. An additional milling step is further included to further mill the hydraulic powder of 1. into smaller particles.
In the examples of the present invention, the grinding aid for hydraulic powder of the present invention is used in the additional grinding for further grinding the powdery raw material for hydraulic powder into finer particles. It can be seen that the grinding aid for hard powder works as a grinding aid.
Of course, the grinding aid for hydraulic powder of the present invention can be applied to a grinding aid such as a clinker or a finishing grinding aid, based on the above findings.

The grinding aid for hydraulic powder of the present invention may be a powder or an aqueous solution, and in the case of powder, it may be added as it is, or may be added after being dissolved in water.

The content of the polyacrylic acid salt in the grinding aid for hydraulic powder of the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, further preferably 30% by mass or more, and preferably 100% by mass. It may be 100% by mass or less, and may be 100% by mass or less. That is, the grinding aid for hydraulic powder of the present invention may be composed of the polyacrylate salt.

The amount of the grinding aid for hydraulic powder of the present invention added to the raw material for hydraulic powder is determined by the fluidity of the hydraulic composition after kneading the hydraulic powder, water, aggregate and dispersant. From the viewpoint, the amount converted to the polyacrylic acid salt is preferably 0.0001 parts by mass or more, more preferably 0.001 parts by mass or more, and further preferably 0 with respect to 100 parts by mass of the raw material for hydraulic powder. 0.01 parts by mass or more, more preferably 0.02 parts by mass or more, and preferably 0.1 parts by mass or less from the viewpoint of preventing false coagulation.
Furthermore, when the dispersant is a naphthalenesulfonic acid formaldehyde condensate, the amount of the grinding aid for hydraulic powder of the present invention added to the hydraulic powder is the amount converted to the polyacrylate salt from the viewpoint of fluidity. Therefore, the amount is more preferably 0.05 part by mass or more, still more preferably 0.07 part by mass or more, relative to 100 parts by mass of the raw material for hydraulic powder.

Further, the addition amount of the grinding aid for hydraulic powder of the present invention to the raw material for hydraulic powder is the fluidity in the hydraulic composition after kneading and preparing hydraulic powder, water, aggregate and dispersant. From the viewpoint of the above, the amount converted to polyacrylic acid is preferably 0.00005 parts by mass or more, more preferably 0.0005 parts by mass or more, still more preferably 0.10 parts by mass with respect to 100 parts by mass of the raw material for hydraulic powder. 005 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.1 parts by mass or less from the viewpoint of preventing false coagulation.
Further, when the dispersant is a naphthalene sulfonic acid formaldehyde condensate, the amount of the grinding aid for hydraulic powder of the present invention added to the raw material for hydraulic powder is the amount converted to polyacrylic acid from the viewpoint of fluidity. Then, it is more preferably 0.03 parts by mass or more, still more preferably 0.05 parts by mass or more, relative to 100 parts by mass of the hydraulic powder raw material.

The grinding aid for hydraulic powder of the present invention may further contain an antifoaming agent from the viewpoint of suppressing the strength reduction due to the increase of the air amount. As the defoaming agent, one or more kinds selected from silicone-based defoaming agents, fatty acid ester-based defoaming agents and ether-based defoaming agents are preferable. Among the silicone-based defoaming agents, dimethylpolysiloxane is more preferable, and fatty acid ester-based defoaming agents are preferable. The foaming agent is more preferably a polyalkylene glycol fatty acid ester, and the ether antifoaming agent is more preferably a polyalkylene glycol ether.

<Hydraulic composition>
The hydraulic composition of the present invention contains the grinding aid for hydraulic powder, hydraulic powder, dispersant and water.
To the hydraulic composition of the present invention, the matters described in the grinding aid for hydraulic powder of the present invention can be applied appropriately.

The dispersant according to the present invention is not particularly limited as long as it is a dispersant generally known for hydraulic compositions, and polycarboxylic acid-based copolymers, naphthalene-based polymers, melamine-based polymers. , Phenol-based polymers, lignin-based polymers, phosphoric acid ester-based polymers and the like. From the viewpoint of water-reducing property and fluidity retention performance of hydraulic powder, polycarboxylic acid-based copolymers and naphthalene-based polymers are preferable. It is one or more selected from coalesce, melamine-based polymers and phosphoric acid ester-based polymers, and more preferably one or more selected from polycarboxylic acid-based copolymers and naphthalene-based polymers. The polycarboxylic acid-based copolymer excludes the polyacrylic acid salt used as the grinding aid for hydraulic powder of the present invention.

As the naphthalene-based polymer, a naphthalenesulfonic acid formaldehyde condensate or a salt thereof, for example, Mighty 150 manufactured by Kao Corporation can be used. As the melamine-based polymer, melamine sulfonic acid formaldehyde condensate or a salt thereof, for example, Mighty 150-V2 manufactured by Kao Corporation can be used. As the phenolic polymer, a phenol sulfonic acid formaldehyde condensate or a salt thereof, for example, the compound described in JP-A-49-104919 can be used. As the lignin-based polymer, lignin sulfonic acid or a salt thereof, for example, Ultragin NA manufactured by Boregard Co., Ultrazine NA manufactured by Borregaard Co., Ltd., Sun Extract manufactured by Nippon Paper Chemical Co., Ltd., SAN X, Vanillex, VANILLEX, Pearlex, PEARLLEX, BASF. For example, Master Pozzolith No. 70 series manufactured by the company can be used.

When the naphthalene polymer is a naphthalene sulfonic acid formaldehyde condensate or a salt thereof, the weight average molecular weight is preferably 1,000 or more, more preferably 5,000 or more, from the viewpoint of fluidity of the hydraulic composition. It is more preferably 10,000 or more, and from the same viewpoint, it is preferably 50,000 or less, more preferably 30,000 or less, still more preferably 20,000 or less.
The weight average molecular weight of the naphthalenesulfonic acid formaldehyde condensate or a salt thereof can be measured by gel permeation chromatography under the following conditions.
[GPC conditions]
Column: G4000SWXL+G2000SWXL (Tosoh Corporation)
_{Eluent: 30mM CH 3 COONa / CH 3} CN = 6/4
Flow rate: 0.7 ml/min
Detection: UV280nm
Sample size: 0.2mg/ml
Standard substance: manufactured by Nishio Industry Co., Ltd. Sodium polystyrene sulfonate conversion (monodisperse sodium polystyrene sulfonate: molecular weight, 206, 1800, 4,000, 8,000, 18,000, 35,000, 88,000, 780,000)
Detector: Tosoh Corporation UV-8020

Examples of the polycarboxylic acid-based polymer include (1) one or more monoesters selected from polyesters of polyalkylene glycol and acrylic acid and monoesters of polyalkylene glycol and methacrylic acid, and acrylic acid and methacrylic acid. Copolymers with one or more selected carboxylic acids and the like (compounds described in JP-A-8-12397), (2) unsaturated alcohol having polyalkylene glycol, and 1 selected from acrylic acid and methacrylic acid. A copolymer with at least one carboxylic acid or the like, a copolymer with (3) an unsaturated alcohol having a polyalkylene glycol and a dicarboxylic acid such as maleic acid, or the like can be used.

The polycarboxylic acid polymer is obtained by polymerizing a monomer containing a monomer (A1) represented by the following general formula (A1) and a monomer (A2) represented by the following general formula (A2). The copolymer thus obtained [hereinafter referred to as the copolymer (A)] is preferable.

[In the formula,
R ¹ and R ² : each independently a hydrogen atom or a methyl group m 1:0 to an integer of 2 or less AO: an alkyleneoxy group having 2 or 3 carbon atoms n 1: an average addition mole number of AO, and 4 or more and 300 or less Number X: represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. ]

[In the formula,
^{R 3, R 4, R 5} : each independently a hydrogen atom, a methyl group, or _{(CH ²⁾} m2 COOM ₂
M ¹ and M ² : each independently represents a counter ion, and is a hydrogen ion, an alkali metal ion, an alkaline earth metal ion (1/2 ion), an organic ammonium ion, or an ammonium ion,
m2: Indicates an integer of 0 or more and 2 or less. ]

The copolymer (A) is obtained by polymerizing a monomer containing the monomer (A1) represented by the general formula (A1) and the monomer (A2) represented by the general formula (A2). It is a copolymer obtained as a result.

In general formula (A1), R ¹ and R ² are each a hydrogen atom or a methyl group. From the viewpoint of fluidity of the hydraulic composition, R ¹ is preferably a hydrogen atom. R ² is preferably a methyl group from the viewpoint of fluidity of the hydraulic composition.
From the viewpoint of fluidity of the hydraulic composition, m1 is an integer of 0 or more and 2 or less, and 0 is preferable.
From the viewpoint of fluidity of the hydraulic composition, AO is an alkyleneoxy group selected from an alkyleneoxy group having 2 carbon atoms and an alkyleneoxy group having 3 carbon atoms, and an ethyleneoxy group is preferable.
n1 is the average number of moles of AO added, and is 4 or more and 300 or less. From the viewpoint of fluidity of the hydraulic composition, n1 is preferably 9 or more, more preferably 15 or more, still more preferably 20 or more. And 200 or less are preferable, 130 or less are more preferable, 100 or less are still more preferable, 80 or less are still more preferable, 50 or less are still more preferable, and 30 or less are still more preferable.
X is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and from the viewpoint of fluidity of the hydraulic composition, a hydrogen atom or an alkyl group having 1 carbon atom is preferable, and an alkyl group having 1 carbon atom is more preferable. ..

As the monomer (A1), (1) methoxypolyethylene glycol, methoxypolypropyleneglycol, methoxypolybutyleneglycol, methoxypolystyreneglycol, ethoxypolyethylenepolypropyleneglycol, etc., one-terminal alkyl-blocked polyalkyleneglycol, acrylic acid, methacrylic acid, And an esterified product with a carboxylic acid selected from maleic acid, and (2) an ethylene oxide and/or propylene oxide adduct to a carboxylic acid selected from acrylic acid, methacrylic acid, and maleic acid. From the viewpoint of fluidity of the hydraulic composition, the monomer (A1) is preferably methoxypolyethylene glycol.

In general formula (A2), R ³ , R ⁴ , and R ⁵ are each independently a hydrogen atom, a methyl group, or (CH ₂ ) _m2 COOM ² . From the viewpoint of the fluidity of the hydraulic composition slurry, R ³ and R ⁵ are preferably hydrogen atoms, and R ⁴ is preferably a methyl group. M ¹ and M ² each represent a hydrogen atom or a counter ion, and are a hydrogen atom, an alkali metal ion, an alkaline earth metal ion (1/2 ion), an ammonium ion, or an organic ammonium ion, and the hydraulic composition From the viewpoint of fluidity, a hydrogen ion or an alkali metal ion is preferable, and a hydrogen atom is more preferable.

Examples of the monomer (A2) include monocarboxylic acid type monomers such as acrylic acid, methacrylic acid and crotonic acid, dicarboxylic acid type monomers such as maleic acid, itaconic acid and fumaric acid, and anhydrides thereof. Examples thereof include salts such as alkali metal salts, alkaline earth metal salts, ammonium salts, and mono-, di-, and trialkyl (having 2 to 8 carbon atoms) ammonium salts in which a hydroxyl group may be substituted. From the viewpoint of fluidity of the hydraulic composition, preferably acrylic acid, methacrylic acid, maleic acid, and alkali metal salts thereof, and a monomer selected from maleic anhydride, more preferably acrylic acid, methacrylic acid. And a monomer selected from these alkali metal salts. Further preferred are monomers selected from methacrylic acid and alkali metal salts of methacrylic acid.

The molar ratio (A1)/(A2) of the monomer (A1) and the monomer (A2) of the copolymer (A) is 10 from the viewpoint of fluidity and fluidity retention of the hydraulic composition. /90 or more is preferable, and 20/80 or more is more preferable. And 60/40 or less is preferable, 50/50 or less is more preferable, 35/65 or less is further preferable, and 30/70 or less is even more preferable.

The total amount of the monomer (A1) and the monomer (A2) in all the constituent monomers of the copolymer (A) is 90 mass from the viewpoint of fluidity and fluidity retention of the hydraulic composition. % Or more, preferably 95% by mass or more, and 100% by mass or less, and may be 100% by mass.

The ratio of the mass of the monomer (A2) to the total mass of the monomer (A1) and the monomer (A2) is 1% by mass or more from the viewpoint of fluidity and fluidity retention of the hydraulic composition. Preferably, 3% by mass or more is more preferable, 4% by mass or more is more preferable, and 100% by mass or less is preferable, 90% by mass or less is more preferable, 80% by mass or less is further preferable, and 70% by mass or less is further It is preferably 50% by mass or less, and further preferably.

From the viewpoint of fluidity of the hydraulic composition, the weight average molecular weight of the copolymer (A) is preferably 10,000 or more, more preferably 20,000 or more, further preferably 30,000 or more, and preferably 200,000 or less, and 100,000 or less. More preferable.
The weight average molecular weight of the copolymer (A) is based on the gel permeation chromatography method (converted to polyethylene glycol), and the specific conditions are as follows.
*Gel permeation chromatography conditions Device: GPC (HLC-8320GPC) Tosoh Corporation Column: G4000PWXL+G2500PWXL (Tosoh Corporation)
Eluent: 0.2 M phosphate buffer/CH ₃ CN=9/1
Flow rate: 1.0 mL/min
Column temperature: 40°C
Detection: RI
Sample size: 0.2mg/mL
Standard substance: Polyethylene glycol equivalent (monodisperse polyethylene glycol with molecular weight 87500, 250,000, 145,000, 46,000, 24,000)

The copolymer (A) can be produced, for example, under the conditions of Production Example 12 of JP-A-8-12397. For example, the copolymer (A) is prepared by charging a monomer (A1), a monomer (A2), and water into a reaction vessel, heating the mixture to a predetermined temperature, and then adding a monomer (A1) and a monomer. It can be produced by reacting the product (A2) with a polymerization initiator or a chain transfer agent at a predetermined molar ratio (A1)/(A2), aging and neutralizing.

The hydraulic powder used in the hydraulic composition of the present invention is a powder having physical properties of being hardened by a hydration reaction, and examples thereof include cement and gypsum. Preferred are normal Portland cement, belite cement, moderate heat cement, fast-strength cement, super fast-strength cement, sulfate resistant cement and the like, and blast furnace slag, fly ash, silica fume, stone powder (calcium carbonate powder), etc. Blast furnace slag cement, fly ash cement, silica fume cement, etc. to which is added may be used. The hydraulic composition finally obtained by adding sand, sand and gravel as an aggregate to these powders is generally called mortar and concrete, respectively.

In the hydraulic composition of the present invention, the content of the grinding aid for hydraulic powder is from the viewpoint of fluidity of the hydraulic composition after kneading and preparing the hydraulic powder, water and aggregate. The amount converted to the polyacrylate is preferably 0.0001 parts by mass or more, more preferably 0.001 parts by mass or more, and still more preferably 0.01 parts by mass with respect to 100 parts by mass of the hydraulic powder. The amount is more preferably 0.02 parts by mass or more, and is preferably 0.1 parts by mass or less from the viewpoint of preventing false coagulation.
Further, when the dispersant is a naphthalene sulfonic acid formaldehyde condensate, the content of the grinding aid for hydraulic powder is the hydraulic powder 100 in terms of fluidity in terms of the polyacrylic acid salt. The amount is more preferably 0.05 part by mass or more, and still more preferably 0.07 part by mass or more, relative to parts by mass.

Further, in the hydraulic composition of the present invention, the content of the grinding aid for hydraulic powder is the fluidity of the hydraulic composition after kneading and preparing the hydraulic powder, water, aggregate and dispersant. From the viewpoint, the amount converted to polyacrylic acid is preferably 0.00005 parts by mass or more, more preferably 0.0005 parts by mass or more, and further preferably 0.005 parts by mass with respect to 100 parts by mass of the hydraulic powder. Parts or more, more preferably 0.01 parts by mass or more, and preferably 0.1 parts by mass or less from the viewpoint of preventing false coagulation.
Furthermore, when the dispersant is a naphthalene sulfonic acid formaldehyde condensate, the content of the grinding aid for hydraulic powder is 100 parts by mass of hydraulic powder in terms of polyacrylic acid from the viewpoint of fluidity. On the other hand, the amount is more preferably 0.03 part by mass or more, still more preferably 0.05 part by mass or more.

In the hydraulic composition of the present invention, the content of the dispersant is preferably 0.001 part by mass or more, and more preferably 100 parts by mass from the viewpoint of fluidity of the hydraulic powder. The amount is 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and preferably 5.0 parts by mass or less, more preferably 3.0 parts by mass or less, still more preferably 2.0 parts by mass or less.

In the hydraulic composition of the present invention, water/hydraulic powder×100 [mass percentage (mass %) of water and hydraulic powder in the slurry, usually abbreviated as W/P, the powder is cement). In some cases, it may be abbreviated as W/C. ], from the viewpoint of workability of the hydraulic composition, preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, and from the viewpoint of workability of the hydraulic composition, It is preferably 80% by mass or less, more preferably 70% by mass or less, still more preferably 60% by mass or less.

The hydraulic composition of the present invention can contain an aggregate. Examples of aggregates include aggregates selected from fine aggregates and coarse aggregates. Examples of fine aggregates include those specified in JIS A0203-2302. As fine aggregate, river sand, land sand, mountain sand, sea sand, lime sand, silica sand and crushed sand of these, blast furnace slag fine aggregate, ferronickel slag fine aggregate, lightweight fine aggregate (artificial and natural) and recycled Fine aggregates and the like can be mentioned. Further, as the coarse aggregate, those specified in JIS A0203-2303 can be mentioned. For example, as coarse aggregate, river gravel, land gravel, mountain gravel, sea gravel, lime gravel, crushed stone of these, blast furnace slag coarse aggregate, ferronickel slag coarse aggregate, lightweight coarse aggregate (artificial and natural) and recycled Examples include coarse aggregate. Fine aggregates and coarse aggregates may be used by mixing different types, or may be used by a single type.

The content of the aggregate of the hydraulic composition of the present invention, from the viewpoint of separation resistance and workability of the hydraulic composition, 1700 kg / m ³ or more per volume of the hydraulic composition is preferably, 1720kg / m ³ or more, and then, preferably 1800 kg / ^{m 3} or less, 1760kg / ^{m 3} or less is more preferable.

The volume ratio [s/a×100(%)] of the fine aggregate (s) in the aggregate (a) in the hydraulic composition of the present invention is from the viewpoint of separation resistance and workability of the hydraulic composition. Therefore, 45% or more is preferable, 47% or more is more preferable, 55% or less is preferable, and 53% or less is more preferable.

The hydraulic composition of the present invention may contain the following components as an example of components other than the grinding aid for hydraulic powder, the dispersant, the hydraulic powder, water and the aggregate.
-AE agent: resin soap, saturated or unsaturated fatty acid, sodium hydroxystearate, lauryl sulfate, alkylbenzene sulfonic acid or its salt, alkane sulfonate, polyoxyalkylene alkyl (phenyl) ether, polyoxyalkylene alkyl (phenyl) ether sulfate ester Or salt thereof, polyoxyalkylene alkyl (phenyl) ether phosphate or salt thereof, protein material, alkenyl succinic acid, α-olefin sulfonate, etc. ・foaming agent ・thickening agent ・silica sand ・foaming agent ・waterproofing material: resin acid Or its salt, fatty acid ester, oil and fat, silicone, paraffin, asphalt, wax, blast furnace slag, fluidizer, defoaming agent: dimethylpolysiloxane-based, polyalkylene glycol fatty acid ester-based, mineral oil-based, oil-based, oxyalkylene-based , Alcohol-based, amide-based, etc. ・Antifoaming agent ・Rust preventive: Nitrite, phosphate, zinc oxide, etc. ・Water-soluble polymer: Methylcellulose, cellulose such as hydroxyethylcellulose, β-1,3-glucan, xanthan gum, etc. Natural products, polyacrylic acid amides, polyethylene glycol, ethylene oxide adducts of oleyl alcohol or synthetic products of vinyl cyclohexene diepoxide and its reaction products, etc. ・Polymer emulsion: Monomer of (meth)acrylate etc. Polymer emulsion using the body

The hydraulic composition of the present invention is for use in ready-mixed concrete, concrete vibration product fields, for self-leveling, for refractories, for plaster, for gypsum slurry, for light or heavy concrete, for AE, for repair, for prepacked, trayy. It is useful in any field of various concretes such as concrete, grout, ground improvement, and cold weather.

<Method for producing hydraulic composition>
The method for producing a hydraulic composition of the present invention is a method for producing a hydraulic composition including the following steps.
Step 1: A step of adding the grinding aid for hydraulic powder and grinding the raw material for hydraulic powder to obtain hydraulic powder.
Step 2: A step of kneading the composition containing the hydraulic powder obtained in Step 1, the dispersant and water.
The method for producing a hydraulic composition of the present invention is a method for producing a hydraulic composition including the following steps.
Step 1: A step of adding the polyacrylic acid salt and pulverizing a raw material for hydraulic powder to obtain hydraulic powder.
Step 2: A step of kneading the composition containing the hydraulic powder obtained in Step 1, the dispersant and water.
In the method for producing a hydraulic composition of the present invention, the matters described for the grinding aid for hydraulic powder and the hydraulic composition of the present invention can be appropriately applied.

In step 1, the pulverization conditions may be adjusted so that a powder having an appropriate particle size can be obtained depending on the raw material, application, and the like. Generally, the specific surface area, Blaine value, preferably up to 2500 cm ² / g or more, more preferably 3000 cm ² / g or more, and, preferably 5000 cm ² / g or less, more preferably less than or equal to the powder 4000 cm ² / g It is preferable to grind clinker, gypsum, etc., which are raw materials for hydraulic powder. The target Blaine value can be obtained, for example, by adjusting the grinding time. The Blaine value tends to increase as the milling time increases, and the Blaine value tends to decrease as the milling time decreases.

The crushing device used for crushing clinker, which is a raw material for hydraulic powder, is not particularly limited, and examples thereof include a ball mill generally used for crushing cement and the like. The material of the crushing medium (crushing ball) of the apparatus is preferably one having a hardness equal to or higher than that of the object to be crushed (for example, calcium aluminate in the case of cement clinker), and in general commercially available products, for example, Examples thereof include steel, stainless steel, alumina, zirconia, titania, tungsten carbide and the like.

The addition amount of the grinding aid for hydraulic powder was converted to the polyacrylic acid salt from the viewpoint of fluidity of the hydraulic composition after kneading and preparing the hydraulic powder, water and aggregate. The amount is preferably 0.0001 parts by mass or more, more preferably 0.001 parts by mass or more, still more preferably 0.01 parts by mass or more, still more preferably 0, based on 100 parts by mass of the hydraulic powder raw material. The amount is preferably 0.02 parts by mass or more, and is preferably 0.1 parts by mass or less from the viewpoint of preventing false coagulation.
Furthermore, when the dispersant is a naphthalene sulfonic acid formaldehyde condensate, the amount of the grinding aid for hydraulic powder added is the amount converted to the polyacrylate salt from the viewpoint of fluidity. The amount is more preferably 0.05 part by mass or more, still more preferably 0.07 part by mass or more, relative to 100 parts by mass of the raw material.

Further, the addition amount of the grinding aid for hydraulic powder is converted to polyacrylic acid from the viewpoint of fluidity in the hydraulic composition after kneading and preparing hydraulic powder, water, aggregate and dispersant. With respect to 100 parts by mass of the raw material for hydraulic powder, preferably 0.00005 parts by mass or more, more preferably 0.0005 parts by mass or more, still more preferably 0.005 parts by mass or more, still more preferably The amount is 0.01 parts by mass or more, and preferably 0.1 parts by mass or less from the viewpoint of preventing false coagulation.
Further, when the dispersant is a naphthalene sulfonic acid formaldehyde condensate, the amount of the grinding aid for hydraulic powder added is a polyacrylic acid-converted amount from the viewpoint of fluidity. It is more preferably 0.03 parts by mass or more, and even more preferably 0.05 parts by mass or more, relative to parts by mass.

In step 2, the hydraulic composition is prepared by mixing the hydraulic powder obtained in step 1, the dispersant and water. From the viewpoint of smoothly mixing the hydraulic powder obtained in step 1 and the dispersant, it is preferable to mix water and the dispersant in advance and then mix with the hydraulic powder obtained in step 1. The mixing can be performed using a mixer such as a mortar mixer and a forced biaxial mixer. Further, the mixture is preferably mixed for 1 minute or more, more preferably 2 minutes or more, and preferably 5 minutes or less, more preferably 3 minutes or less. In preparing the hydraulic composition, the materials, agents and their amounts described in the hydraulic composition can be used.

The dispersant is not particularly limited as long as it is a dispersant generally known for hydraulic compositions, polycarboxylic acid-based copolymer, naphthalene-based polymer, melamine-based polymer, phenol-based. Polymers, lignin-based polymers, phosphoric acid ester-based polymers and the like, and from the viewpoint of water-reducing property and fluidity retention performance of hydraulic powder, preferably polycarboxylic acid-based copolymers and naphthalene-based polymers, melamine. It is one or more selected from the group-based polymer and the phosphoric acid ester-based polymer, and more preferably one or more is selected from the polycarboxylic acid-based copolymer and the naphthalene-based polymer.

As the grinding aid and the dispersant shown in Tables 2 to 7, the following were used. In addition, the contents of the grinding aid and the dispersant in Tables 2 to 7 are the amounts in terms of solid content.
(Crushing aid)
・Sodium polyacrylate 1: Poiz 530, weight average molecular weight 37,000, solid content concentration 40 mass% aqueous solution manufactured by Kao Corporation ・Sodium polyacrylate 2: synthetic product by a conventional method, weight average molecular weight 49,000, solid Aqueous solution having a concentration of 40% by mass, sodium polyacrylate 3: manufactured by Toagosei Co., Ltd., 10 L of JULIMER, a weight average molecular weight of 106,000, an aqueous solution having a solid content of 40% by mass, ammonium polyacrylate: manufactured by Kao Corporation, Poiz532A Aqueous solution having a weight average molecular weight of 40,000 and a solid content of 40% by mass, triethanolamine: manufactured by Kishida Chemical Co., Ltd., a reagent/acrylic acid/maleic acid copolymer: manufactured by Kao Corporation, Poiz521, a weight average molecular weight of 30, 000, sodium salt, aqueous solution with solid content concentration of 40% by mass

The weight average molecular weights of sodium polyacrylate 1, sodium polyacrylate 2 and sodium polyacrylate 3 are values measured by the gel permeation chromatography method (polyethylene glycol conversion) under the following conditions.
*Gel permeation chromatography conditions Device: GPC (HLC-8320GPC) Tosoh Corporation Column: G4000PWXL+G2500PWXL (Tosoh Corporation)
Eluent: 0.2 M phosphate buffer/CH ₃ CN=9/1
Flow rate: 1.0 mL/min
Column temperature: 40°C
Detection: RI
Sample size: 0.2mg/mL
Standard substance: Polyethylene glycol equivalent (monodisperse polyethylene glycol with molecular weight 87500, 250,000, 145,000, 46,000, 24,000)

(Dispersant)
NSF: naphthalene polymer (manufactured by Kao Corporation, Mighty 150, naphthalenesulfonic acid formaldehyde condensate, molecular weight 13,000, solid part concentration 40 mass% aqueous solution)
PCE: polycarboxylic acid type dispersant (manufactured in the following manufacturing example, aqueous solution having a solid content concentration of 40% by mass)

<Example of PCE production>
A glass reaction vessel (four-necked flask) equipped with a stirrer was charged with 333 g of water, the atmosphere was replaced with nitrogen while stirring, and the temperature was raised to 80° C. in a nitrogen atmosphere. ω-Methoxypolyethylene glycol monomethacrylate (average addition mole number 23 of ethylene oxide: NK ester M230G, Shin-Nakamura Chemical Co., Ltd., monomer (A1)) 300 g, methacrylic acid (reagent: Wako Pure Chemical Industries, Ltd., 69.7 g of the monomer (A2) and 6.3 g of 3-mercaptopropionic acid in 200 g of water are mixed and dissolved, and 12.3 g of ammonium persulfate is dissolved in 45 g of water. It dripped in the said reaction container over 5 hours. Then, the mixture was aged at 80° C. for 1 hour, an aqueous solution of 4.9 g of ammonium persulfate dissolved in 15 g of water was added dropwise over 30 minutes, and subsequently aged at 80° C. for 1.5 hours. After completion of aging, the mixture was cooled to 40° C. or lower and then neutralized with 48% sodium hydroxide aqueous solution 47.2 g to obtain a copolymer having a weight average molecular weight of 43,000 (neutralization degree 0.7). Then, the solid content was adjusted to 20% by mass with water. The mass ratio of the monomer (A2) to the total mass of the monomer (A1) and the monomer (A2) was 75% by mass.

<Production example of hydraulic powder>
Ordinary Portland cement (combination of commercially available Taiheiyo Cement Co. and commercially available Sumitomo Osaka Cement Co. at 50 mass% each) as a raw material for hydraulic powder was mixed with each grinding aid in Tables 2-7. (A grinding aid was not added unless stated in the column of the grinding aid in the table) and crushed for 3 minutes with a ball mill to obtain a hydraulic powder for evaluation.
The ball mill used was AXB-15 manufactured by Seiwa Giken Co., Ltd., the stainless pot capacity was 18 liters (outer diameter 300 mm), and 30 stainless steel balls were 30 mmφ (nominal 1.1/4) and 20 mmφ (nominal 3/ In 4), a total of 100 balls of 70 balls were used, and the rotation speed of the ball mill was about 30 rpm (20 Hz).
The discharging time from the ball mill was 2 minutes.
The Blaine value of the ordinary Portland cement used here was 3300 cm ² /g, and the Blaine value after pulverization was 3500 cm ² /g. For the measurement of the Blaine value, a Blaine air permeable device specified in the physical test method for cement (JISR5201) was used.

<Production Example of Hydraulic Composition>
Using the mortar mixer (Dalton Co. universal mixing stirrer model: 5DM-03-γ) under the mixing conditions shown in Table 1, each hydraulic powder (P) and fine aggregate (S) obtained above were obtained. Was added to carry out empty kneading for 10 seconds, and kneading water (W) containing a dispersant was added. Then, the hydraulic composition was prepared by kneading the mortar mixer at low speed (62 rpm) for 60 seconds and further at high speed (125 rpm) for 60 seconds.
The components of water (W) and fine aggregate (S) in Table 1 are as follows.
Water (W): Distilled water Hydraulic powder (P): Each hydraulic powder fine aggregate obtained above (S): Joyo Sansand W/P is [content of water (W)] /[Content of each hydraulic powder (P) obtained above] x 100% by mass.
Further, since the amount of the dispersant in the kneading water is very small, the amount of the kneading water including the amount of the dispersant is set as W in Table 1.

<Evaluation of liquidity>
The mortar flow of each obtained hydraulic composition was measured according to JIS R5201. The measurement was performed immediately after the kneading (0 minutes).

<Evaluation of false coagulation>
Immediately after kneading after contact with water, when the mortar, which is a hydraulic composition, stiffened rapidly and showed a state of being temporarily set, it was judged to be pseudo-setting. In the table, the following criteria evaluated and the result was shown.
None: No false coagulation Yes With: False coagulation

Examples 1-1 and 1-2, Comparative examples 1-1 to 1-4
The hydraulic powder was prepared by adding the grinding aid shown in Table 2, and the hydraulic composition was prepared by adding the dispersing agent shown in Table 2 to the obtained hydraulic powder. Then, the fluidity of the obtained hydraulic composition was evaluated. The results are shown in Table 2.

In Table 2, the addition amount is the addition amount of the effective component based on 100 parts by mass of the raw material for hydraulic powder or hydraulic powder.
Further, each relative value of fluidity is a value when Comparative Example 1-2 and Example 1-1 are set to 100 as Comparative Example 1-1, and Comparative Example 1-4 and Example 1-2. Is a value when Comparative Example 1-3 is set to 100.

In Examples 1-1 and 1-2 in which sodium polyacrylate 1 was added as a grinding aid, it can be seen that the fluidity of the hydraulic composition is improved by both dispersants of NSF and PCE.

Comparative Example 2-1
In Comparative Example 2-1, sodium polyacrylate 1 was not added at the time of pulverizing the hydraulic powder, but was added at the time of preparing the hydraulic composition. Then, the fluidity of the obtained hydraulic composition was evaluated. The results are shown in Table 3. Table 3 also shows the results of Example 1-1 and Comparative example 1-1.

In Table 3, the addition amount is the addition amount of the effective component with respect to 100 parts by mass of the raw material for hydraulic powder or hydraulic powder.
Further, each relative value of fluidity is a value when Comparative Example 1-1 is set to 100.

Compared to Comparative Example 2-1 in which sodium polyacrylate 1 was added at the time of preparing the hydraulic composition, Example 1-1 in which sodium polyacrylate 1 was added at the time of crushing the hydraulic powder was a hydraulic composition. It can be seen that the liquidity of is improved.

Examples 3-1 to 3-10, Comparative examples 3-1 and 3-2
A hydraulic powder was prepared by adding sodium polyacrylate 1 as a grinding aid in an addition amount shown in Table 4, and a hydraulic composition was prepared by adding the dispersant shown in Table 4 to the obtained hydraulic powder. The thing was prepared. Then, the fluidity and coagulation of the obtained hydraulic composition were evaluated. The results are shown in Table 4.

In Table 4, the addition amount is the addition amount of the effective component based on 100 parts by mass of the raw material for hydraulic powder or hydraulic powder.
Moreover, each relative value of the fluidity is a value when Comparative Example 3-1 is set to 100 for Examples 3-1 to 3-5, and Comparative Examples 3-6 to 3-10. It is a value when Example 3-2 is set to 100.

Examples 4-1 to 4-6, Comparative examples 4-1 to 4-12
A hydraulic powder was prepared by adding the grinding aid shown in Table 5, and the dispersant shown in Table 5 was added to the obtained hydraulic powder so that the content shown in Table 5 was obtained. The thing was prepared. Then, the fluidity of the obtained hydraulic composition was evaluated. The results are shown in Table 5.

In Table 5, the addition amount is the addition amount of the effective component with respect to 100 parts by mass of the raw material for hydraulic powder or hydraulic powder.

Using sodium polyacrylate 1 to compare Examples 4-1 to 4-6 and Comparative Examples 4-1 to 4-12 to obtain the same degree of fluidity of the hydraulic composition, sodium polyacrylate 1 was used. It can be seen that the addition amount of is small.

Examples 5-1 and 5-2, Comparative examples 5-1 to 5-6
A hydraulic powder was prepared by adding the grinding aid shown in Table 6, and a dispersant shown in Table 6 was added to the obtained hydraulic powder to prepare a hydraulic composition. Then, the fluidity of the obtained hydraulic composition was evaluated. The results are shown in Table 6.

In Table 6, the addition amount is the addition amount of the effective component with respect to 100 parts by mass of the raw material for hydraulic powder or hydraulic powder.
Moreover, each relative value of fluidity is a value when Example 5-1 and Comparative Examples 5-2 and 5-3 are set to 100 in Comparative Example 5-1. Examples 5-5 and 5-6 are values when Comparative Example 5-4 is set to 100.

In Comparative Examples 5-2, 5-3, 5-5 and 5-6 in which a compound having a chemical structure different from that of the polyacrylic acid salt of the present invention was added as a powdering aid, the fluidity of the hydraulic composition is not improved. I understand.

Examples 6-1 and 6-2, Comparative examples 6-1 to 6-6
The hydraulic powder was prepared by adding the grinding aid shown in Table 7, and the dispersant shown in Table 7 was added to the obtained hydraulic powder to prepare a hydraulic composition. Then, the fluidity of the obtained hydraulic composition was evaluated. The results are shown in Table 7.

In Table 7, the addition amount is the addition amount of the effective component with respect to 100 parts by mass of the raw material for hydraulic powder or hydraulic powder.
Moreover, each relative value of fluidity is a value when Example 6-1 and Comparative Examples 6-2 and 6-3 are set to 100 in Comparative Example 6-1. Examples 6-5 and 6-6 are values when Comparative Example 6-4 is set to 100.

In Comparative Examples 6-2, 6-3, 6-5 and 6-6 in which the weight average molecular weight of the polyacrylic acid salt of the present invention does not satisfy the conditions of the present application, the fluidity of the hydraulic composition is not improved. I understand.

Claims (7)

A hydraulic property containing one or more polyacrylates selected from polyacrylic acid alkali metal salts having a weight average molecular weight of 30,000 to 45,000 and polyacrylic acid alkaline earth metal salts having a weight average molecular weight of 30,000 to 45,000. A grinding aid for powders. The grinding aid for hydraulic powder according to claim 1, comprising, as the polyacrylic acid salt, one or more compounds selected from alkali metal polyacrylates having a weight average molecular weight of 30,000 or more and 45,000 or less. A method for producing a hydraulic composition, which comprises the following steps.
Step 1: 0.0001 parts by mass or more of the grinding aid for hydraulic powder according to claim 1 or 2 in an amount converted to the polyacrylate salt with respect to 100 parts by mass of the raw material for hydraulic powder. A step of adding at 0.1 part by mass or less and crushing the raw material for hydraulic powder to obtain hydraulic powder.
Step 2: A step of kneading the composition containing the hydraulic powder obtained in Step 1, the dispersant and water. The method for producing a hydraulic composition according to claim 3, wherein the dispersant is a naphthalene-based polymer or a polycarboxylic acid-based polymer. A hydraulic composition containing the grinding aid for hydraulic powder according to claim 1 or 2, a hydraulic powder, a dispersant and water. The hydraulic composition according to claim 5 , wherein the dispersant is a naphthalene-based polymer or a polycarboxylic acid-based polymer. The content of the grinding aid for hydraulic powder is 0.0001 parts by mass or more and 0.1 parts by mass or less based on 100 parts by mass of the hydraulic powder, in an amount converted to the polyacrylate. The hydraulic composition according to claim 5 or 6 .