JP3209894B2 - High performance water reducing agent composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION The present invention provides cement compositions, in particular mortars and concretes, with high fluidity and resistance to material separation, so that the prepared cement compositions can be molded without vibration compaction. The present invention relates to a high-performance water reducing agent composition that can be poured into the composition.

[0002]

BACKGROUND OF THE INVENTION When a cement compound such as concrete is given high fluidity and resistance to material separation, the concrete can be poured into a form as it is. Therefore, conventionally, various cement dispersants have been used to impart high fluidity to the cement composition in order to impart high fluidity and material separation resistance to the cement composition, while increasing the viscosity of the cement composition. As a method for imparting material separation resistance to a cement mixture, 1) a method of using a relatively large amount of fine powder materials such as blast furnace slag fine powder, fly ash, and rock fine powder, 2) methylcellulose, hydroxyalkylcellulose, polyacrylamide 3) A method using a combination of the above-mentioned fine powder material and a thickener has been attempted.

[0003] However, the fine powder material as described above is very troublesome to handle in the preparation of a cement composition due to its properties. Thickeners such as those described above have low solubility in water, so that they are also very troublesome to handle in the preparation of the cement composition, and also have a reduced drying shrinkage upon curing of the prepared cement composition. large. Attempts have been made to prepare a mixed solution of a cement dispersant and a thickener in advance and use the mixed solution during the preparation of a cement composition, but it is troublesome to prepare such a mixed solution in the first place. In addition, the stability of the prepared mixture over time is poor, so that the desired effect cannot actually be obtained stably.

[0004] As the thickener, a basic hydroxide formed by a hydration reaction of cement, typically a viscosity increase due to an increase in pH due to calcium hydroxide,
An aqueous dispersion of an anionic acrylic polymer obtained by copolymerizing (meth) acrylic acid and (meth) acrylic acid ester has been proposed (Japanese Patent Publication 5-87461). However, even if a thickener such as described above is used in combination with a known cement dispersant, for example, an organic sulfonate-based or polycarboxylate-based cement dispersant to prepare a cement composition, the cement composition is actually not The thickening effect of the period cannot be obtained. The reason is that the carboxyl group of the anionic acrylic polymer which is a component of the aqueous dispersion used as a thickener is neutralized by calcium hydroxide to become calcium carboxylate, and such a polymer has a solubility in water. This is because it will decrease.

[0005]

The problem to be solved by the present invention is that, in the conventional method, the operation of preparing a cement compound is extremely troublesome, and the desired thickening effect cannot be stably obtained. The point is that the prepared cement composition has a large drying shrinkage upon curing.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the inventors have found that a specific vinyl polymer emulsion is used as a thickener and a specific water-soluble emulsion is used as a cement dispersant. It has been found that the use of vinyl copolymers is correct and preferred.

That is, the present invention relates to an aqueous mixture of the following vinyl polymer emulsion and the following water-soluble vinyl copolymer, which has a pH of 4 to 8 and a viscosity formed by a hydration reaction of cement. The present invention relates to a high-performance water reducing agent composition characterized by comprising an aqueous mixture which is twice or more in a pH range of 9 or more caused by a basic hydroxide.

[0008] Vinyl polymer emulsion: an aqueous emulsion of a vinyl polymer obtained by copolymerizing all vinyl monomers containing a vinyl monomer having a carboxylic acid group in an amount of 3 to 75% by weight of the total vinyl monomers. Aqueous emulsion water-soluble vinyl copolymer having a pH of 4 to 8:
Consisting of the structural unit represented by the formula 4, the structural unit represented by the formula 1 / the structural unit represented by the formula 2 / the structural unit represented by the formula 3 / the structural unit represented by the formula 4 = 40 to 65
/ 15 to 35/2 to 20/5 to 20 (mol%) and a number average molecular weight of 1500 to 5000
0 water-soluble vinyl copolymer

[0009]

(Equation 1)

(Equation 2)

(Equation 3)

(Equation 4)

In the formulas (1) to (4), R ¹ , R ² , R ⁴ : H or CH ₃ R ³ : an alkyl group having 1 to ³ carbon atoms M ¹ , M ² : an alkali metal, an alkaline earth metal, ammonium or Organic amine n: an integer of 5 to 50

The vinyl polymer emulsion used in the present invention is an aqueous emulsion of a vinyl polymer obtained by copolymerizing a vinyl monomer having a carboxylic acid group and another vinyl monomer copolymerizable therewith. An aqueous emulsion in which all the carboxylic acid groups contained in the vinyl polymer exist in a free state without forming a salt, and have a liquid property of pH 4 to 8. As the aqueous emulsion, those described in JP-B-5-87461 can be applied.

The vinyl monomer having a carboxylic acid group includes
Ethylenically unsaturated monocarboxylic acids and ethylenically unsaturated dicarboxylic acids are included. Examples of the ethylenically unsaturated monocarboxylic acid include acrylic acid, methacrylic acid, crotonic acid, and the like, and examples of the ethylenically unsaturated dicarboxylic acid include maleic acid, itaconic acid, and fumaric acid. As the vinyl monomer having a group, acrylic acid and methacrylic acid are preferred.

In the vinyl polymer emulsion used in the present invention, the vinyl monomer having a carboxylic acid group accounts for 3 to 75% by weight of the total vinyl monomer. The present invention does not particularly limit the types of other vinyl monomers copolymerizable with the vinyl monomer having a carboxylic acid group, and such other vinyl monomers include ethyl (meth) acrylate. , Butyl (meth) acrylate, octyl (meth) acrylate,
Alkyl (meth) acrylate having 1 to 12 carbon atoms in the alkyl group, such as lauryl (meth) acrylate, is preferred.

The present invention does not particularly limit the method for producing a vinyl polymer emulsion, and any known method can be applied to the method for producing the vinyl polymer emulsion. Among them, radicals such as persulfates, peroxides, and redox initiators can be used. A method of producing by emulsion polymerization using water as a dispersion medium using a polymerization initiator is preferable.

According to the present invention, the number average molecular weight of the vinyl polymer in the vinyl polymer emulsion (GPC method, in terms of polystyrene, hereinafter the same for vinyl polymer) is usually from 20,000 to 1,000,000, preferably from 50,000 to 800,000. And In the vinyl polymer emulsion obtained by the emulsion polymerization described above,
The solid content is usually adjusted to 20 to 40% by weight, and the liquid property shows pH 4 to 8, but it is preferable to adjust it to pH 4 to 7. In such a pH range, the vinyl polymer is usually emulsified and dispersed in water as fine particles having a diameter of 2 to 3 μm or less.
Shows a low viscosity of 0.001 to 0.05 Pa · s.

In the vinyl polymer emulsion used in the present invention, the vinyl polymer is obtained by copolymerizing a vinyl monomer having a carboxylic acid group at a ratio of 3 to 75% by weight based on the total vinyl monomer as described above. However, it is preferable to determine the copolymerization ratio of the vinyl monomer having a carboxylic acid group such that the acid value based on the carboxylic acid group contained in the vinyl polymer is 30 to 500, and the acid value is 50 to 500. More preferably, the copolymerization ratio of the vinyl monomer having a carboxylic acid group is determined so as to be 460.

The water-soluble vinyl copolymer used in the present invention comprises the structural units represented by the above formulas (1) to (4). Examples of the vinyl monomer that forms the structural unit represented by Formula 1 include an alkali metal salt, an alkaline earth metal salt, an ammonium salt, and an organic amine salt of (meth) acrylic acid. Examples of the vinyl monomer that forms the structural unit represented by Formula 2 include alkoxypolyethoxyethyl (meta) having 5 to 50 repeating oxyethylene units and having 1 to 3 carbon atoms in an alkoxy group. )
Acrylates are mentioned. Further, as the vinyl monomer which forms the structural unit represented by the formula 3, an alkali metal salt, an alkaline earth metal salt of methallyl sulfonic acid,
Examples include ammonium salts or organic amine salts. Examples of the vinyl monomer that forms the structural unit represented by Formula 4 include an alkyl (meth) acrylate having 1 to 3 carbon atoms.

The water-soluble vinyl copolymer used in the present invention comprises the structural units represented by the above-described formulas (1) to (4).
/ Structural unit represented by Formula 3 / Structural unit represented by Formula 4 = 40 to 65/15 to 35/2 to 20
/ 5 to 20 (mol%).

In the present invention, the method for producing the water-soluble vinyl copolymer is not particularly limited, and a known method, for example, a method described in Japanese Patent Publication No. 5-11057 can be applied to the production method. it can. For example, it can be obtained by radical copolymerization of each of the above-mentioned vinyl monomers with an aqueous solution so as to have a predetermined copolymerization ratio in the presence of a radical initiator. In the aqueous solution of the water-soluble vinyl copolymer thus obtained, the solid content is usually adjusted to 20 to 40% by weight, and the liquid property is adjusted to pH 6 to 9. Such a water-soluble vinyl copolymer has a number average molecular weight of 1500 to 50,000 (G
PC method, pullulan conversion, the same applies hereinafter for water-soluble vinyl copolymer), but 2000 to 20,000
It is preferred to use

The high-performance water reducing agent composition of the present invention is an aqueous mixture obtained by mixing the above-mentioned vinyl polymer emulsion and the above-mentioned water-soluble vinyl copolymer. The polymer is advantageously mixed using its aqueous solution. In such a high-performance water reducing agent composition, the solid concentration is usually 20 to 30% by weight.
The pH of the solution is adjusted to pH 4 to 8.

In the high-performance water reducing agent composition of the present invention, the mixing ratio of the vinyl polymer emulsion and the water-soluble vinyl copolymer is such that the ratio of the vinyl polymer / water-soluble vinyl copolymer is 2/9.
It is preferable to mix so as to be 8 to 60/40 (weight ratio of solid content), and 5/95 to 50/50 (weight ratio of solid content).
It is more preferable to mix them so that

The high-performance water reducing agent composition of the present invention has the above-mentioned p
It has a very low viscosity in the H4-8 range. For example, the viscosity of an aqueous solution having a solid concentration of 25% by weight is 20 ° C.
And about 0.005 to 0.1 Pa · s. When the pH is increased to 9 or more by a basic hydroxide generated by the hydration reaction of cement, typically calcium hydroxide, the vinyl polymer becomes calcium carboxylate, but the action of the water-soluble vinyl copolymer used in combination causes the vinyl polymer to become calcium carboxylate. Even with such a vinyl polymer, the solubility does not decrease, so that the viscosity of the high-performance water reducing agent composition of the present invention becomes at least two times or more, usually five times or more in a pH range of 9 or more. When the high-performance water reducing agent composition of the present invention is added during the preparation of a cement composition, the high-performance water reducing agent composition significantly thickens due to a pH increase caused by a basic hydroxide generated by a hydration reaction of cement. As a result, it is possible to simultaneously impart the desired high fluidity and material separation resistance to the prepared cement compound.

The high-performance water reducing agent composition of the present invention comprises a polymer emulsion and a cement dispersant as described above, and when used, may be used in combination with other agents for the purpose. it can. Such other agents include air entrainers, defoamers, setting accelerators, setting retarders, rust inhibitors,
Swelling agents, preservatives and the like. And how to use it,
Either a method of adding the kneading water together with the kneading water at the time of preparing the cement composition or a method of adding the kneading water to the cement composition after kneading may be used.

The high-performance water reducing agent composition of the present invention can be used for a cement compound prepared using a binder comprising cement or a combination of cement and a fine powder admixture, specifically, mortar and concrete. Can be. As the cement, various portland cements such as ordinary portland cement, early-strength portland cement, and moderately heated portland cement, as well as fly ash cement, blast furnace cement, silica cement, various mixed cements, and the like can be used. Silica fume, blast furnace slag fine powder, fly ash and the like can be used. The high-performance water reducing agent composition of the present invention is generally used in a range of 0.25 to 2.0% by weight in terms of solid content based on cement or a binder composed of cement and a fine powder admixture.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention include the following 1) to 5). 1) An aqueous mixture of the following vinyl polymer emulsion (20 parts by weight) and the following water-soluble vinyl copolymer aqueous solution (80 parts by weight), which has a pH of 6.0 and a viscosity due to a hydration reaction of cement. PH due to the generated basic hydroxide
9.2. A high performance water reducing agent composition consisting of an aqueous mixture that multiplies by 225 times.

Vinyl polymer emulsion: An aqueous emulsion of a vinyl polymer having a number average molecular weight of 120,000 copolymerized by emulsion polymerization using water as a dispersion medium in a ratio of methacrylic acid / ethyl acrylate = 50/50 (weight ratio). The liquid property shows pH 4.9 and the solid content concentration is 25% by weight.
Aqueous emulsion.

An aqueous solution of a water-soluble vinyl copolymer: forms a vinyl monomer, sodium methacrylate, which forms a structural unit represented by the above formula 1, and a structural unit represented by the above formula 2 Methoxypolyethoxyethyl (n = 9, n is the number of repetitions of oxyethylene units, the same applies hereinafter) methacrylate, which is a different vinyl monomer, and vinyl monomer which forms the structural unit represented by the above formula 3 Water-soluble vinyl having a number average molecular weight of 5500, which is obtained by copolymerizing sodium methallyl sulfonate as a monomer and methyl acrylate as a vinyl monomer to form a structural unit represented by the above formula 4 in an aqueous solution. It is a copolymer, and the ratio of each constitutional unit is represented by the constitutional unit represented by the formula 1 / the constitutional unit represented by the formula 2 / the constitutional unit represented by the formula 3 / the formula 4 Constituent units = 49/28/11/12
(Mol%) is a water-soluble vinyl copolymer aqueous solution having a pH of 7.5 and a solid content of 25% by weight.
Aqueous solution.

2) The following vinyl polymer emulsion 15
An aqueous mixture of parts by weight and 85 parts by weight of an aqueous solution of the following water-soluble vinyl copolymer, wherein the liquidity has a pH of 6.2 and the viscosity is attributed to a basic hydroxide produced by a hydration reaction of cement. A high-performance water reducing agent composition comprising an aqueous mixture that becomes 127 times higher at a pH of 9.2.

Vinyl polymer emulsion: An aqueous emulsion of a vinyl polymer having a number average molecular weight of 200,000 and copolymerized by emulsion polymerization using water as a dispersion medium in a ratio of methacrylic acid / ethyl acrylate = 35/65 (weight ratio). The liquid property shows pH 5.1 and the solid content concentration is 25% by weight.
Aqueous emulsion.

An aqueous solution of a water-soluble vinyl copolymer: forms a vinyl monomer, sodium methacrylate, which forms the structural unit represented by the above formula 1, and a structural unit represented by the above formula 2 Methoxypolyethoxyethyl (n = 9) methacrylate, which is a different vinyl monomer; sodium methallyl sulfonate, which is a vinyl monomer that forms the structural unit represented by the above formula 3, Is a water-soluble vinyl copolymer having a number average molecular weight of 5500, which is obtained by copolymerizing a vinyl monomer, methyl acrylate, which forms a structural unit represented by Formula 4 with an aqueous solution. Structural unit represented by formula 1 / structural unit represented by formula 2 / structural unit represented by formula 3 / structural unit represented by formula 4 = 49/28/11 /
An aqueous solution of 12 (mol%) of a water-soluble vinyl copolymer having a liquid property of pH 7.5 and a solid content of 25% by weight.

3) An aqueous mixture of 7 parts by weight of the following vinyl polymer emulsion and 93 parts by weight of an aqueous solution of the following water-soluble vinyl copolymer, having a liquid property of pH 6.0 and a viscosity of water of cement A high-performance water reducing agent composition comprising an aqueous mixture that becomes 56-fold at pH 9.2 due to a basic hydroxide formed by a sum reaction.

Vinyl polymer emulsion: An aqueous emulsion of a vinyl polymer having a number average molecular weight of 80,000, copolymerized by emulsion polymerization using water as a dispersion medium at a ratio of methacrylic acid / ethyl acrylate = 70/30 (weight ratio). The liquid has a pH of 4.7 and a solid content of 25% by weight.
Aqueous emulsion.

Aqueous solution of a water-soluble vinyl copolymer: forms a structural unit represented by the above formula 2 with sodium methacrylate which is a vinyl monomer to form a structural unit represented by the above formula 1 Methoxypolyethoxyethyl (n = 9) methacrylate, which is a different vinyl monomer; sodium methallyl sulfonate, which is a vinyl monomer that forms the structural unit represented by the above formula 3, Is a water-soluble vinyl copolymer having a number average molecular weight of 5500, which is obtained by copolymerizing a vinyl monomer, methyl acrylate, which forms a structural unit represented by Formula 4 with an aqueous solution. Structural unit represented by formula 1 / structural unit represented by formula 2 / structural unit represented by formula 3 / structural unit represented by formula 4 = 49/28/11 /
An aqueous solution of 12 (mol%) of a water-soluble vinyl copolymer having a liquid property of pH 7.5 and a solid content of 25% by weight.

4) The following vinyl polymer emulsion 10
An aqueous mixture of parts by weight and 90 parts by weight of an aqueous solution of the following water-soluble vinyl copolymer, wherein the liquidity has a pH of 6.0 and the viscosity is attributed to a basic hydroxide generated by a hydration reaction of cement. A high-performance water reducing agent composition comprising an aqueous mixture that becomes 50 times higher at a pH of 9.2.

Vinyl polymer emulsion: acrylic acid /
Ethyl acrylate = 15/85 (weight ratio) Number average molecular weight 3 copolymerized by emulsion polymerization using water as a dispersion medium
An aqueous emulsion of a 00000 vinyl polymer having a liquid property of pH 4.3 and a solid content of 25% by weight.
Aqueous emulsion.

An aqueous solution of a water-soluble vinyl copolymer: forms a vinyl monomer, sodium methacrylate, which forms the structural unit represented by the above formula 1, and a structural unit represented by the above formula 2 Methoxypolyethoxyethyl (n = 23) methacrylate, which is a different vinyl monomer; sodium methallyl sulfonate, which is a vinyl monomer that forms the structural unit represented by the above formula 3, Is a water-soluble vinyl copolymer having a number average molecular weight of 66,000, which is obtained by copolymerizing a vinyl monomer, methyl acrylate, which will form the structural unit represented by Formula 4 with an aqueous solution, and the ratio of each structural unit is Structural unit represented by formula 1 / structural unit represented by formula 2 / structural unit represented by formula 3 / structural unit represented by formula 4 = 55/20/1
An aqueous solution of 0/15 (mol%) of a water-soluble vinyl copolymer having a pH of 7.8 and a solid content of 25.
Aqueous solution that is wt%.

5) An aqueous mixture of 5 parts by weight of the following vinyl polymer emulsion and 95 parts by weight of an aqueous solution of the following water-soluble vinyl copolymer, wherein the liquid has a pH of 6.5 and a viscosity of water of cement. A high-performance water reducing agent composition comprising an aqueous mixture that becomes 10 times higher at pH 9.2 due to a basic hydroxide formed by a sum reaction.

Vinyl polymer emulsion: methacrylic acid / ethyl acrylate / butyl acrylate = 20/55 /
An aqueous emulsion of a vinyl polymer having a number average molecular weight of 450,000 copolymerized by emulsion polymerization using water as a dispersion medium at a ratio of 25 (weight ratio), having a liquid property of pH 5.2 and a solid content concentration of 25% by weight. % Aqueous emulsion.

Aqueous solution of a water-soluble vinyl copolymer: forms a vinyl monomer, sodium acrylate, which forms a structural unit represented by the above formula 1, and a structural unit represented by the above formula 2 Methoxypolyethoxyethyl (n = 23) methacrylate, which is a different vinyl monomer; sodium methallyl sulfonate, which is a vinyl monomer that forms the structural unit represented by the above formula 3, Is a water-soluble vinyl copolymer having a number average molecular weight of 8300 obtained by copolymerizing methyl acrylate, which is a vinyl monomer to form a structural unit represented by Formula 4, with an aqueous solution. Structural unit represented by formula 1 / structural unit represented by formula 2 / structural unit represented by formula 3 / structural unit represented by formula 4 = 50/23/15 /
An aqueous solution of 12 (mol%) of a water-soluble vinyl copolymer having a pH of 7.7 and a solid content of 25% by weight.

Hereinafter, examples and the like will be described in order to make the structure and effect of the present invention more specific, but the present invention is not limited to the examples. In the following examples and the like, parts mean parts by weight, and% means% by weight excluding the amount of air.

[0041]

[Example] Test Category 1 (Preparation of Vinyl Polymer Emulsion) Preparation of Vinyl Polymer Emulsion E-1 125 parts of methacrylic acid (1.45 mol) and 125 parts of ethyl acrylate (1.25 mol) in a reaction vessel. , 10 parts of sodium polyoxyethylene alkylphenol sulfate and 670 parts of ion-exchanged water were charged and emulsified while stirring.
Next, the temperature of the reaction system was maintained at 50 ° C., and the atmosphere was replaced with nitrogen. Then, 20 parts of a 2% aqueous solution of sodium persulfate and 20 parts of a 2% aqueous solution of sodium sulfite were added dropwise to initiate polymerization. Two hours after the start of the polymerization, again,
10 parts each of a 2% aqueous solution of sodium persulfate and a 2% aqueous solution of sodium sulfite were added dropwise, and the reaction was continued for 2 hours to complete the polymerization reaction. The partially insolubilized contents were filtered through a filter cloth to obtain a vinyl polymer emulsion. When this was analyzed, the solid content concentration was 25%, the pH was 4.9 (glass electrode method, the same applies hereinafter), and the acid value of the vinyl polymer was 32.
4. The copolymerization ratio of methacrylic acid was 50%, and the number average molecular weight was 250,000.

· Vinyl polymer emulsions E-2 to E-
5, Preparation of ER-1, ER-2 Vinyl polymer emulsions E-2 to E-5, ER-1, ER-
2 was obtained. These contents are summarized in Table 1.

[0043]

[Table 1]

Test Category 2 (Preparation of aqueous solution of water-soluble vinyl copolymer) Preparation of aqueous solution P-1 of water-soluble vinyl copolymer In a reaction vessel, 80 parts (0.930 mol) of methacrylic acid, 20 parts of methyl acrylate (0.233 mol), 35 parts (0.222 mol) of sodium methallylsulfonate, methoxypolyethoxyethyl (n = 9, n is the number of repeating oxyethylene units, the same applies hereinafter) 300 parts of methacrylate (0.605 mol) ), 500 parts of water were charged, and 124 parts of a 30% aqueous solution of sodium hydroxide was added to neutralize the mixture, and the mixture was uniformly dissolved. After that, the atmosphere was replaced with nitrogen. The temperature of the reaction system was maintained at 60 ° C., and a 15% aqueous solution of ammonium persulfate was used.
The polymerization was started by charging the parts and the polymerization reaction was continued for 6 hours to complete the polymerization. Then, 3 to neutralize the acidic decomposition products
5 parts of a 0% aqueous sodium hydroxide solution was added to adjust the pH to 7.
5, to obtain an aqueous solution P-1 of a water-soluble vinyl copolymer having a solid content of 25%. After a part of the aqueous solution was concentrated by an evaporator, the solution was precipitated and purified in a mixed solvent of acetone / isopropanol and dried to take out a water-soluble vinyl copolymer. This water-soluble vinyl copolymer had a carboxyl number of 122 and a sulfur content of 1.5% by elemental analysis. The copolymerization ratio according to the result of NMR measurement is as follows: sodium methacrylate / methoxypolyethoxyethyl (n
= 9) Methacrylate / sodium methallylsulfonate / methyl acrylate = 49/28/11/12 (molar ratio), and the number average molecular weight was 5,500.

An aqueous solution P-2 of a water-soluble vinyl copolymer,
Preparation of P-3, Pr-1 and Pr-2 The solid content concentration was 2 in the same manner as in the aqueous solution P-1 of the water-soluble vinyl copolymer.
5% aqueous solutions of water-soluble vinyl copolymers P-2, P-3,
Pr-1 and Pr-2 were obtained. These contents are summarized in Table 2.

[0046]

[Table 2]

In Table 2, a to f: vinyl monomers forming each structural unit a: sodium acrylate b: sodium methacrylate c: methoxypolyethoxyethyl (n = 9) methacrylate d: methoxypoly Ethoxyethyl (n = 23) methacrylate e: sodium methallylsulfonate f: methyl acrylate

Test Category 3 (Preparation of High Performance Water Reducing Agent Composition and Evaluation of Its Thickening) Preparation of High Performance Water Reducing Agent Composition Example 1 Two vinyl polymer emulsions E-1 obtained in Test Category 1 were used.
0 parts and 80 parts of the aqueous solution P-1 of the water-soluble vinyl copolymer obtained in Test Category 2 were mixed to obtain a high-performance water reducing agent composition M-1 of the present invention. The pH of the high-performance water reducing agent composition obtained here was 6.0, and the viscosity at 25 ° C measured by a B-type viscometer was 0.0.
It was 27 Pa · s.

Examples 2 to 5 High performance water reducing agent compositions M-2 to M-5 were obtained in the same manner as the high performance water reducing agent composition M-1. The contents of Examples 1 to 5 are summarized in Table 3, and all of them are 6 ° C at 30 ° C.
Even after standing for a month, there was no change in viscosity and a uniform liquid phase was exhibited.

Comparative Example 1 The vinyl polymer emulsion E-1 obtained in Test Category 1
To 0 part, a 25% aqueous solution of calcium hydroxide was added to adjust the pH to 11.5 to prepare a vinyl polymer emulsion. 80 parts of an aqueous solution P-1 of the water-soluble vinyl copolymer obtained in Test Category 2 was mixed with this vinyl polymer emulsion to obtain an aqueous mixture. The aqueous mixture contained a phase separated gel.

Evaluation of thickening: 25% was added to the high-performance water reducing agent composition M-1 prepared in Example 1.
Was added to adjust the pH to 9.2 or 12. The viscosity of these samples was measured at 25 ° C. using a B-type viscometer. Similarly, high performance water reducing agent compositions M-2 to M-5 were measured. These results are summarized in Table 3.

[0052]

[Table 3]

In Table 3, * 1: (viscosity of high performance water reducing agent composition adjusted to pH 9.2) / (viscosity of original high performance water reducing agent composition) * 2: (viscosity of high performance water reducing agent composition adjusted to pH 12) / Viscosity of the original water-reducing agent composition)

Test Category 4 (Preparation and Evaluation of High Fluidity Concrete) Preparation of High Fluidity Concrete (Test Examples 1 to 10) Under the mixing conditions shown in Table 4, a 50-liter pan-type forced mixer was mixed with ordinary Portland cement ( Made by Chichibu Onoda,
Specific gravity = 3.16, Brain value = 3350), fine aggregate (Oigawa river sand, specific gravity = 2.63), coarse aggregate (Okazaki crushed stone,
(Specific gravity = 2.66) was sequentially charged and kneaded for 15 seconds.
Next, in each case, the target slump flow value was 55-6.
The high-performance water reducing agent composition and the like were added to the cement in a range of 0.25 to 2.0% in terms of solid content with mixing water so as to be within a range of 5 cm, and the mixture was kneaded for 2 minutes. The air amount was adjusted by adding an air amount adjusting agent so that the target air amount was 4 ± 1% in each case.

[0055]

[Table 4]

Evaluation of high-fluidity concrete For the high-fluidity concrete prepared above, slump, slump flow value, air volume, material age 7 were determined by the following methods.
The compressive strength after 28 days and 28 days, the drying shrinkage after 28 days and 91 days, the initial flow rate of L flow, and the L slump value were measured. The state of aggregate separation was also observed. The results are summarized in Tables 5 and 6.

..Slump and slump flow value: JI
It was measured according to SA1101 (slump test method for concrete). After the slump cone was pulled up, the length of the maximum diameter of the spread concrete and the length in the direction perpendicular thereto were measured, and the average value was defined as the slump flow value. ··· Air volume: measured in accordance with JIS-A1128. ··· Compressive strength: measured in accordance with JIS-A1108. Dry shrinkage: measured in accordance with JIS-A1129. ··· L flow initial speed: high flow concrete prepared by measuring the L flow initial speed using the L flow tester shown in FIG. 1 (the same type as that described in Japanese Patent Publication No. 5-36377). Was evaluated for viscosity. The illustrated L flow tester has a hollow vertical rectangular parallelepiped 1 and a hollow horizontal rectangular parallelepiped 2 connected to each other and connected at a right angle, and is provided on the inner surface side of the vertical rectangular parallelepiped 1 on the side of the horizontal rectangular parallelepiped 2. The door 3 for partitioning both is mounted so as to be able to move up and down. The initial flow rate of the L-flow is determined by filling the high-flow concrete prepared in the vertically-mounted rectangular parallelepiped 1 with the door 3, and raising the door 3 to completely communicate the vertically-oriented rectangular parallelepiped 1 with the horizontally-oriented rectangular parallelepiped 2. The flow rate between 50 mm and 100 mm from the starting surface of the flow was measured using the optical sensor 4. When the slump flow value is constant, the smaller the value of the L flow initial velocity is, the higher the viscosity is, indicating that the separation resistance of the aggregate is good. ··· L slump value: Two rebars having a diameter of 13 mm were mounted in the horizontal rectangular parallelepiped 2 of the above-mentioned L flow tester in proximity to the door 3. The two rebars were arranged side by side in the width direction at positions symmetrical above and below the horizontal cuboid 2 with an interval of 45 mm therebetween. Fully poured the high-fluidity concrete prepared in the vertically-oriented rectangular parallelepiped 1 and raise the door 3 to completely communicate the vertically-oriented rectangular parallelepiped 1 with the horizontally-oriented rectangular parallelepiped 2 to which two reinforcing bars are attached. Was stopped, the height (cm) of the space formed in the upper part of the rectangular parallelepiped 1 was measured, and this was used as the L slump value to evaluate the inter-rebar passability of the highly fluid concrete. When the L slump value is larger than 30 cm, it indicates that there is no material separation and the fluidity is good. ··· Aggregate separation: Adhesion of cement particles to aggregates was observed with the naked eye in high-fluidity concrete immediately after preparation.

[0058]

[Table 5]

In Table 5, * 3: weight% in terms of solid content relative to cement

[0060]

[Table 6]

In Table 6, * 4:% by weight in terms of solid content with respect to cement * 5:% by weight in terms of solid content with respect to cement * 6: Vinyl polymer emulsion E-1 in Table 1 * 7: Vinyl height in Table 1 Molecular emulsion ER-1 * 8: Vinyl polymer emulsion ER-2 * 9 in Table 1: Target fluidity (slump flow value) could not be obtained

[0062]

As is clear from the above, the present invention described above has the following advantages: 1) it is stable over time; 2) the preparation of the cement composition is simple; and 3) it is superior to the cement composition. 4) It has the effect of exhibiting a thickening effect and simultaneously imparting high fluidity and material separation resistance. 4) It has the effect of reducing drying shrinkage during curing of the prepared cement compound.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an L flow tester used for measuring an L slump value of a high fluidity concrete prepared in the present invention.

[Explanation of symbols]

1 ... vertical cuboid, 2 ... horizontal cuboid, 3 ...
・ Doors, 4 ・ ・ ・ Optical sensor

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Izushi Izumi 1-5-5 Otsuka, Inzai-cho, Inba-gun, Chiba Prefecture Inside the Technical Research Institute, Takenaka Corporation (72) Inventor Kazuma Inoue Otsuka, Inzai-cho, Inba-gun, Chiba Prefecture 1-5-5 Takenaka Corporation Technical Research Institute (72) Inventor Kohei Tanda 1-5-5 Inzai-cho Otsuka, Inba-gun, Chiba Prefecture Incorporated Takenaka Corporation Technical Research Institute (72) Inventor Kaoru Yamazaki Kyoto Prefecture Sanyo Kasei Kogyo Co., Ltd. (72) Inventor, Sanyo Kasei Kogyo Co., Ltd. (72) Inventor, Public Insurance Kuranuki, Kyoto City, Kyoto Prefecture 11 Sanyo Kasei Kogyo Co., Ltd. (72) Inventor, Mitsuo Kinoshita Aichi 308, Shiiki, Tamemachi-cho, Toyokawa-shi, Japan (72) Inventor Yoshimasa Miura 55, Nakayashiki, Ugaike-cho, Nishio-shi, Aichi (56) References JP-A-60-200851 (JP) JP-A-7-118047 (JP, A) JP-A-7-126055 (JP, A) JP-A-7-309656 (JP, A) JP-A 8-11009057 (JP, A) 9-2855 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C04B 24/00-24/42

Claims (4)

(57) [Claims] An aqueous mixture of the following vinyl polymer emulsion and the following water-soluble vinyl copolymer, wherein the basic water has a pH of 4 to 8 and a viscosity formed by a hydration reaction of cement. A high-performance water reducing agent composition comprising an aqueous mixture that becomes twice or more in a pH range of 9 or more caused by an oxide. Vinyl polymer emulsion: an aqueous emulsion of a vinyl polymer obtained by copolymerizing all vinyl monomers containing a vinyl monomer having a carboxylic acid group in an amount of 3 to 75% by weight of the total vinyl monomers, Is an aqueous emulsion water-soluble vinyl copolymer having a pH of 4 to 8: a structural unit represented by the following formulas 1 to 4, wherein the structural unit represented by the formula 1 / the structural unit represented by the formula 2 / Structural unit represented by formula 3 / structural unit represented by formula 4 = 40 to 65/15 to 35/2 to 20/5 to 20
(Mol%) and a water-soluble vinyl copolymer having a number average molecular weight of 1500 to 50,000. (Equation 2) (Equation 3) (Equation 4) (In the formulas 1 to 4, R ¹ , R ² , R ⁴ : H or CH ₃ R ³ : an alkyl group having 1 to ³ carbon atoms M ¹ , M ² : an alkali metal, an alkaline earth metal, ammonium or an organic amine n: an integer of 5 to 50) 2. A vinyl polymer, which is a component of a vinyl polymer emulsion, comprises (meth) acrylic acid and an alkyl (meth) acrylate having an alkyl group having 1 to 12 carbon atoms,
(Meth) acrylic acid / the alkyl (meth) acrylate =
The high-performance water reducing agent according to claim 1, wherein the copolymer has a number average molecular weight of 20,000 to 1,000,000 and is copolymerized by an emulsion polymerization using water at a ratio of 3/97 to 75/25 (% by weight). Composition. 3. The high-performance water reducing agent composition according to claim 1, wherein the vinyl polymer as a component of the vinyl polymer emulsion has an acid value of 30 to 500. 4. An aqueous mixture comprising a vinyl polymer emulsion and a water-soluble vinyl copolymer in a ratio of vinyl polymer / water-soluble vinyl copolymer = 2/98 to 60/40 (weight ratio of solid content). Claim 1, which is a mixture of
4. The high-performance water reducing agent composition according to 2 or 3.