KR20040009222A - Dispersant for cement and concrete - Google Patents

Abstract

PURPOSE: A cement and concrete dispersant having excellent flow property, water reducing property, air entraining property and slump is provided to improve the workability and operation efficiency, and strength and durability after curing. CONSTITUTION: The cement and concrete dispersant comprises a polycarboxylic acid polymer obtained by the esterification of a polycarboxylic acid polymer anhydride of the formula with a polyoxyalkylene glycol derivative of the formula of R10O(R11Om-H), in which R10 is H or a C1-C20 alkyl group, R11O is a C2-C4 oxyalkylene group or a mixture thereof added in the shape of blocks or randomly, and m is an average addition mole number of the oxyalkylene groups and an integer of 1-100, or a salt thereof: wherein R1 and R2 are the same or different and each represents H or a C1-C30 hydrocarbyl group, R3 is H, phenyl, alkylphenyl, sulfonated phenyl, a C1-C30 alkyl, a C2-C30 alkenyl or a select organo-group; R9 is H or methyl, M1 is H, a monovalent metal, a divalent metal, ammonium or an organo-ammonium, and each of p, q and u is a mole ratio of each repeating unit in the polymer and is not 0.

Description

Cement and Concrete Admixtures (Dispersants) {DISPERSANT FOR CEMENT AND CONCRETE}

The present invention relates to a dispersant for cement and concrete, and more particularly, to a cement and concrete admixture (dispersant) having excellent slump and air embrittlement performance of cement paste, mortar, concrete, etc., and having a small amount of coagulation delay and bleeding.

In addition to increasing the strength of concrete, cement and concrete admixtures can be used to obtain high-quality cement formulations such as reduced work load and reduced segregation of aggregates.It is easy to construct dense or difficult vibration parts. It should be possible to give fluidity to upgrade and transport the high part of the high-rise building by high pressure pump.

As the admixture for concrete to achieve this purpose, melamine sulfonic acid formalin high condensate and naphthalene sulfonic acid formalin high condensate have emerged. However, these gouting agents have excellent susceptibility and fluidity, so that high strength, high flow, and high durability concrete can be manufactured, but there is a problem in that slumping is large.

In contrast, the polycarboxylic acid cement admixture not only exhibits excellent water reducibility than conventional cement admixtures, but also exhibits excellent fluid retention and excellent mortar kneading. As these admixtures for polycarboxylic acid cements, admixtures including copolymers obtained by copolymerizing alkoxy polyalkylene glycol acrylates and unsaturated carboxylic acids have been specially disclosed in 2001-0074022, in particular 2000-0029225, in particular 2000-0057113, in particular 1999-. 0068043, patent 1999-0068042, patent 10-0210643, patent 10-0247527, patent 10-0247526 and USP 6,166,112 and the like.

The alkoxy polyalkylene glycol acrylates affecting the coagulation delay of the cement admixtures disclosed in these publications and increasing the steric repulsion to affect dispersion stabilization are values obtained by esterification of unsaturated carboxylic acids with alkoxy polyalkylene glycols. The use of expensive monomers or the need for a separate facility is required in order to produce them directly. Also, these admixtures have a low slump prosperity when used at room temperature and excellent flow retention, but a high slump process when used at high temperature. This has the disadvantage of poor flow retention.

The object of the present invention is excellent flow retention at high temperatures of cement paste, mortar, and concrete, less slump loss, better air stability, less settling time delay and bleeding amount, even when used at room temperature, while reducing the use of conventional water reducing agents. Cement by directly esterifying alkoxy polyalkylene glycol compound to polycarboxylic acid copolymer which has excellent flow retention performance at high temperature, affects setting delay, and increases steric repulsion and affects dispersion stabilization The development of admixtures for solvents eliminates the need for separate equipment for the production of monomers, thereby reducing the reaction time in producing admixtures (dispersants) for cement, as well as polycarboxylic acids or Pipes for dispersants for cement and concrete, salts thereof Will.

The present invention is a cement and concrete admixture that improves the problems occurring in conventional conventional fluidizing agents, in particular polycarboxylic acid-based fluidizing agents, even in the strong alkali atmosphere in the concrete slurry, the dispersing group of the polymer compound maintains a strong binding force until the initial fluidity is poured It is to provide a admixture made of a polymer copolymer that can be maintained, that is, to prevent the occurrence of slumps over time and to improve the workability at the time of pouring and not affected by water hardening to improve the excellent strength and durability of concrete.

Cement admixture prepared by the method of the present invention comprises a polycarboxylic acid polymer having the following repeating units general formula (1) to (4) as a main component under the condition that the median average molecular weight of the polycarboxylic acid polymer is 10,000 or more will be.

Repeating unit represented by general formula (1)

(One)

Wherein R ¹ and R ² are the same or different and represent a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, and R ³ represents a hydrogen atom, a phenyl group, an alkylphenyl group, a sulfonated phenyl group, an alkyl group of 1 to 30 carbon atoms, or a carbon number An alkenyl group of 2 to 30 or a selected organic group consisting of -OR ⁴ , -OCOR ⁵ , -X ¹ OR ⁶ , -0 (R ⁷ O) ₁ R ⁸ and -CN; R ⁴ , R ⁵ each represent 1 carbon atom. A hydrocarbon group of 30 to 30, X ¹ is a divalent hydrocarbon group having 1 to 3 carbon atoms, R ⁶ and R ⁸ are each a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms, and R ⁷ is an alkenyl having 2 to 30 carbon atoms Group, 1 represents the average mole number of the oxyalkylene group represented by-(R ⁷ O)-, and is a positive number of 1 to 300, p represents the appearance fraction (molar ratio) of repeating units in the polycarboxylic acid polymer.)

Repeating unit represented by general formula (2)

(2)

Wherein R ⁹ is hydrogen or a methyl group, M ¹ is hydrogen, a monovalent metal, a divalent metal, ammonium or an organic ammonium, and q represents the occurrence (molar ratio) of the repeating units in the polycarboxylic acid polymer .)

Repeating unit represented by General formula (3)

(3)

(In the above formula, M ² and M ³ may be the same or different and may each have a hydrogen atom, an ammonium group or an organic amine group, and r represents the occurrence (molar ratio) of the repeating units in the polycarboxylic acid polymer.)

Repeating unit represented by general formula (4)

(4)

(In the formula, -R ¹⁰ O- consists of one kind or a mixture of two or more kinds of oxyalkylene groups having 2 to 4 carbon atoms, and in the case of two or more kinds, may be added in block form or randomly added. R ¹¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, M ⁴ is hydrogen, a monovalent metal, a divalent metal, ammonium or an organic ammonium, m is an integer of 1 to 100 as the average added mole number of the oxyalkylene group, s is The appearance fraction (molar ratio) of repeating units in the polycarboxylic acid polymer.)

As mentioned above, the code | symbol p, q, r, and s which each fraction of Formula (1)-(4) shows is not zero.

Hereinafter, the method of the present invention will be described in detail.

In the present invention, the polyoxy represented by the general formula (7) in the general formula (6), which is an anhydride of the polycarboxylic acid polymer composed of the repeating units of the following general formulas (1), (2) and (5) A polycarboxylic acid polymer having a weight molecular weight of 10,000 or more obtained by esterifying an alkylene glycol derivative, specifically, exhibits excellent fluid retention performance and air entrainment performance such as cement paste, mortar, and concrete, and delays coagulation at high and low temperatures. The present invention provides a dispersant for cement and concrete, which is a polycarboxylic acid polymer having excellent retention performance or a salt thereof.

Repeating unit represented by general formula (1)

(One)

(Wherein R ¹ and R ² are the same or different and each represents a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, R ³ represents a hydrogen atom, a phenyl group, an alkylphenyl group, a sulfonyl sulfonyl group, an alkyl group of 1 to 30 carbon atoms, or carbon number) An alkenyl group of 2 to 30 or a selected organic group consisting of -OR ⁴ , -OCOR ⁵ , -X ¹ OR ⁶ , -0 (R ⁷ O) ₁ R ⁸ and -CN; R ⁴ , R ⁵ each represent 1 carbon atom. A hydrocarbon group of 30 to 30, X ¹ is a divalent hydrocarbon group having 1 to 3 carbon atoms, R ⁶ and R ⁸ are each a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms, and R ⁷ is an alkenyl having 2 to 30 carbon atoms Group, 1 represents the average number of oxyalkylene groups represented by-(R ⁷ O)-, and is a positive number of 1 to 300, p represents the appearance fraction (molar ratio) of repeating units in the polycarboxylic acid polymer.)

Repeating unit represented by general formula (2)

(2)

(Wherein R ⁹ is hydrogen or methyl group and M ¹ is hydrogen, monovalent metal, divalent metal, ammonium or organic ammonium, and q represents the appearance fraction (molar ratio) of repeating units in the polycarboxylic acid polymer.)

Repeating unit represented by general formula (5)

(5)

(Wherein u represents the mole fraction of the repeating unit in the polycarboxylic acid polymer (molar ratio) and is not 0.) Anhydride of the polycarboxylic acid polymer represented by the general formula (6), in which the repeating unit is a main component and,

General formula (6)

(6)

(Wherein R ¹ to R ⁹ , M ¹ are as defined above, and p, q and u represent the molar ratio of repeating units in the polycarboxylic acid polymer.)

Polyoxyalkylene glycol compound represented by General formula (7)

(7)

Wherein R ₁₀ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R ₁₁ O is composed of one or two or more mixtures of oxyalkylene groups having 2 to 4 carbon atoms, and in the case of two or more species, It may be added or may be added at random, m represents an integer of 1 to 100 in the average added mole number of the oxyalkylene group.)

As the main constituents of the polycarboxylic acid polymer anhydride represented by the general formula (6) in the present invention, the structural units represented by the general formula (1) are each 1 to 40 mol%, preferably 1 to 30 mol%, more Preferably 1-25 mol%, the structural unit represented by General formula (2) is 90-5 mol%, respectively, Preferably it is 80-10 mol%, More preferably, 75-25 mol% and General formula (5 ) Is a copolymer of 10 to 70 mol%, preferably 20 to 60 mol%, more preferably 25 to 45 mol% of linearly arranged structural units, and the weight average molecular weight is determined by GPC. It is the range of 5,000-100,000 in polyacrylic acid conversion.

The dispersant for cement of the present invention is not 0 in general formulas (1) (2) and (5), and the repeating unit of formula (3) is produced by hydrolysis by adding water, and the repeating unit of (4) Is produced by the esterification reaction of the polycarboxylic acid anhydride represented by the general formula (6) and the polyoxyalkylene glycol compound represented by the general formula (7), wherein the polyoxyalkylene glycol compound The carboxylic acid repeating unit represented by (5) is generally used in an amount of 10 to 90 mol%, preferably 20 to 70 mol%, more preferably 30 to 60 mol%, and the weight average molecular weight of the polymer is It is selected in the range of 10,000-500,000 in polyacrylic acid conversion by GPC.

Since the polymer of the present invention exhibits high sensitivity due to the steric repulsion of the alkoxypolyoxyalkylene group used and the hydrophilic group of oxyalkylene, the average mole number of oxyalkylene is preferably 2 to 100.

In addition, 0.1-10 moles of a derivative having hydroxyl groups at both ends of the polyoxyalkylene used in the esterification reaction in order to compensate for the disadvantage that the polycarboxylic acid-based cement dispersant is poor in fluid retention performance at high temperatures. By crosslinking with the polycarboxylic acid copolymer represented by the general formula (6) using about%, to obtain a dispersant for cement with improved flow retention performance even at high temperatures.

The polymerization reaction of the polycarboxylic acid copolymer of the present invention may also be carried out in a batch or continuous process, and the solvent used is not particularly limited, but may be n-hexane, benzene, toluene, xylene, cyclohexane, or the like. Ester compounds such as aromatic or aliphatic hydrocarbons, ethyl acetate and isopropyl acetate, ketone compounds such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, THF, 1.3-dioxane, and the like. Can be used and must be used after removing moisture.

When the polymerization reaction is polymerized using one of the above solvents or a mixed solvent, a peroxide such as benzoyl peroxide, lauryl peroxide, hydroperoxide such as cumene hydroperoxide, azobisisobutyro, etc. Azo compounds, such as a nitrile, etc. can be used, Accelerators, such as an amine compound, can also be used together and it is performed within the temperature range of 50-200 degreeC. At this time, the weight average molecular weight of the copolymer is preferably in the range of 500 to 100,000, particularly 5,000 to 100,000. If the weight average molecular weight is less than 500, the sensitivity of the cement dispersant is lowered, which is not preferable. On the other hand, at a molecular weight of more than 500,000, the susceptibility of the cement dispersant and the ability to prevent slumping are reduced, which is undesirable.

Although the catalyst used for said esterification reaction is not specifically limited, Inorganic acid, ie, sulfuric acid, p-toluenesulfonic acid, etc. can be used individually or in mixture of them. At this time, the solvent used is used as it is the solvent used in the polymerization, and the resulting water is separated using an oil / water separator at the water / solvent azeotropic point. The completion of the reaction was determined by acid value measurement. After completion of the reaction, the organic solvent used was distilled and recovered, and the reaction was terminated by adding a predetermined amount of water to the produced copolymer.

The copolymer thus obtained is used as a main component of the cement admixture as it is, but if necessary, the copolymer salt obtained by neutralizing with an alkaline substance may be used as the main component of the cement dispersant. As such an alkaline substance, inorganic substances, such as a monovalent metal, the hydroxide of a divalent metal, chloride, and a carbon salt, ammonia, an organic amine, etc. can be used.

The weight average molecular weight of the copolymer or copolymer salt to be used as the cement admixture for the present invention is preferably in the range of 5,000 to 300,000, particularly 10,000 to 300,000. In addition, the polydispersity ranges from 1 to 100, preferably from 2 to 50. If the weight average molecular weight is less than 1,000, the susceptibility of the cement dispersant is deteriorated, which is not preferable. At the molecular weight of more than 500,000, the susceptibility of the cement dispersant and the ability to prevent slumping are deteriorated.

In addition, the cement dispersant may be used in combination with at least one cement dispersant selected from the group consisting of conventionally known naphthalene cement dispersants, amino sulfonic acid cement dispersants and lignin cement dispersants, in addition to air emollients, wetting agents, Expanding agents, waterproofing agents, retardants, rapideners, other water-soluble polymers, midpoints, flocculants, shrinkage reducing agents, strength enhancers, antifoaming agents, and the like can be blended.

The dispersion of cement is promoted by blending a cement dispersant containing the copolymer thus obtained as a main component in a cement composition composed of at least cement and water.

The cement dispersant of the present invention can be used for hydraulic materials such as portland cement, high-light cement, alumina cement, mixed cement, or other hydraulic materials other than cement such as gypsum.

Hereinafter, the present invention will be described in detail with reference to Examples. The following examples illustrate a limited case to more specifically describe the contents of the present invention, but the scope of the present invention is not limited thereto.

Example 1.

500 parts of toluene and 100 parts of maleic anhydride were put into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the reactor was nitrogen-substituted under stirring to heat to 120 ° C. under a nitrogen atmosphere. Next, a solution containing 86 parts of methacrylic acid and 20 parts of methyl (meth) acrylate mixed with 100 parts of toluene and 20 parts of 50% methyl ethyl ketone peroxide solution was added dropwise for 4 hours, and after completion of dropping, methoxy polyethylene glycol (ethylene oxide average 400 parts of 10 moles of additional moles) were dripped. After the dropwise addition, the esterification reaction was performed while maintaining the temperature of the reactor at 120 ° C., and the reaction was completed when the acid value of the reaction mixture reached 50 to 70 (mgKOHg). After completion of the reaction, the toluene in the liquid was removed by vacuum distillation. After cooling, water was added, and the mixture was neutralized with 130 parts of a 50% aqueous solution of caustic soda to obtain a cement admixture containing a copolymer solution having a weight average molecular weight of 18,500.

Example 2.

500 parts of toluene and 100 parts of maleic anhydride were put into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the mixture was nitrogen-substituted under stirring, and heated to 120 ° C. under a nitrogen atmosphere. Next, a solution obtained by mixing 86 parts of methacrylic acid and 20 parts of methyl (meth) acrylate with 100 parts of toluene and 20 parts of 50% methyl ethyl jatone peroxide solution was added dropwise for 4 hours, and after completion of the dropwise addition, methoxy polyethylene glycol (ethylene oxide average 390 parts of addition mole number 4 mol) was dripped. After the dropwise addition, the esterification reaction proceeded while maintaining the temperature of the reactor at 120 ° C., and the reaction was completed when the acid value of the reaction mixture reached 50 to 70 (mgKOH / g). After completion of the reaction, the toluene in the liquid was removed by vacuum distillation. After cooling, water was added, and the mixture was neutralized with 64 parts of 50% aqueous solution of caustic soda to obtain a cement admixture containing a copolymer aqueous solution having a weight average molecular weight of 15,100.

Example 3.

500 parts of toluene and 100 parts of maleic anhydride were put into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the mixture was nitrogen-substituted under stirring, and heated to 120 ° C. under a nitrogen atmosphere. Next, a solution obtained by mixing 86 parts of methacrylic acid and 20 parts of methyl (meth) acrylate and 100 parts of toluene and 20 parts of 50% methyl ethyl ketone peroxide solution was added dropwise for 4 hours, and after completion of the dropwise addition, methoxy polyethylene glycol (ethylene oxide average 600 parts of addition mole number 15 mol) was dripped. After the dropwise addition, the esterification reaction proceeded while maintaining the temperature of the reactor at 120 ° C., and the reaction was completed when the acid value of the reaction mixture reached 50 to 70 (mgKOH / g). After completion of the reaction, toluene in the liquid was removed by vacuum distillation. After cooling, water was added, and the mixture was neutralized with 130 parts of a 50% aqueous solution of caustic soda to obtain a cement admixture containing an aqueous copolymer solution having a weight average molecular weight of 19,600.

Example 4.

500 parts of toluene and 100 parts of maleic anhydride were put into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the mixture was nitrogen-substituted under stirring, and heated to 120 ° C. under a nitrogen atmosphere. Next, a solution obtained by mixing 86 parts of methacrylic acid and 20 parts of methyl (meth) acrylate and 100 parts of toluene and 20 parts of 50% methyl ethyl ketone peroxide solution was added dropwise for 4 hours, and after completion of the dropwise addition, methoxy polyethylene glycol (ethylene oxide average 25 mol of additional moles) 1,700 parts was dripped. After the dropwise addition, the esterification reaction proceeded while maintaining the temperature of the reactor at 120 ° C., and the reaction was completed when the acid value of the reaction mixture reached 50 to 70 (mgKOH / g). After completion of the reaction, the toluene in the liquid was removed by vacuum distillation. After cooling, water was added, and the mixture was neutralized with 100 parts of 50% aqueous solution of caustic soda to obtain a cement admixture containing a copolymer solution having a weight average molecular weight of 20,500.

Example 5.

500 parts of toluene and 100 parts of maleic anhydride were put into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the mixture was nitrogen-substituted under stirring, and heated to 120 ° C. under a nitrogen atmosphere. Next, a solution obtained by mixing 86 parts of methacrylic acid and 20 parts of methyl (meth) acrylate and 100 parts of toluene and 20 parts of 50% methyl ethyl ketone peroxide solution was added dropwise for 4 hours, and after completion of the dropwise addition, methoxy polyethylene glycol (ethylene oxide average 2,100 parts of addition mole number 40 mol) was dripped. After the dropwise addition, the esterification reaction proceeded while maintaining the temperature of the reactor at 120 ° C., and the reaction was completed when the acid value of the reaction mixture reached 50 to 70 (mgKOH / g). After completion of the reaction, the toluene in the liquid was removed by vacuum distillation. After cooling, water was added, and the mixture was neutralized with 120 parts of a 50% aqueous solution of caustic soda to obtain a cement admixture with a copolymer aqueous solution having a weight average molecular weight of 19,300.

Example 6.

500 parts of toluene and 100 parts of maleic anhydride were put into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the mixture was nitrogen-substituted under stirring, and heated to 120 ° C. under a nitrogen atmosphere. Next, 86 parts of methacrylic acid and 20 parts of 50% methyl ethyl ketone peroxide solution were added dropwise for 4 hours. After completion of the dropwise addition, 1,500 parts of methoxy polyethylene glycol (25 moles of ethylene oxide average added mole number) were added dropwise. After the dropwise addition, the esterification reaction proceeded while maintaining the temperature of the reactor at 120 ° C., and the reaction was completed when the acid value of the reaction mixture reached 50 to 70 (mgKOH / g). After completion of the reaction, the toluene in the liquid was removed by vacuum distillation. After cooling, water was added, and the mixture was neutralized with 100 parts of 50% aqueous solution of caustic soda to obtain a cement admixture containing an aqueous copolymer solution having a weight average molecular weight of 21,700.

Example 7.

500 parts of toluene and 100 parts of maleic anhydride were put into a glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the mixture was nitrogen-substituted under stirring, and heated to 120 ° C. under a nitrogen atmosphere. Next, 86 parts of methacrylic acid and 20 parts of 50% methyl ethyl ketone peroxide solution were added dropwise for 4 hours, and after completion of the dropwise addition, 700 parts of methoxy polyethylene glycol (22 moles of ethylene oxide added) and polyethylene glycol (average added moles of ethylene oxide). 10 mole) 10 part mixed solution was dripped. After the dropwise addition, the esterification reaction proceeded while maintaining the temperature of the reactor at 120 ° C., and the reaction was completed when the acid value of the reaction mixture reached 50 to 70 (mgKOH / g). After completion of the reaction, the toluene in the liquid was removed by vacuum distillation. After cooling, water was added, and the mixture was neutralized with 150 parts of 50% aqueous solution of caustic soda to obtain a cement admixture containing an aqueous copolymer solution having a weight average molecular weight of 23,700.

Comparative Example 1.

300 parts of distilled water was put into the glass reactor equipped with the thermometer, the stirrer, the dropping funnel, the nitrogen inlet tube, and the reflux cooling device, and the inside of the reactor was nitrogen-substituted under stirring, and the temperature was raised to 80 ° C. under a nitrogen atmosphere. Next, 150 parts of methoxy polyethylene glycol monomethacrylate (23 moles of ethylene oxide added), 50 parts of metal acrylic acid, 150 parts of water, and 4 parts of 3-mercaptopropionic acid as a chain transfer agent and 10% soda persulfate 40 parts of aqueous solution was dripped for 3 hours, and 10 parts of 10% sodium persulfate aqueous solution was dripped further for 1 hour after completion | finish of dripping. Subsequently, the mixture was maintained at 80 ° C. for 1 hour to complete the polymerization reaction, and neutralized with 37 parts of 50% aqueous solution of caustic soda to obtain a cement admixture containing an aqueous copolymer solution having a weight average molecular weight of 25,100.

Comparative Example 2.

300 parts of distilled water was put into the glass reactor equipped with the thermometer, the stirrer, the dropping funnel, the nitrogen inlet tube, and the reflux cooling device, and the inside of the reactor was nitrogen-substituted under stirring, and the temperature was raised to 80 ° C. under a nitrogen atmosphere. Next, 180 parts of methoxy polyethylene glycol monomethacrylate (10 moles of ethylene oxide added), 20 parts of metal acrylic acid, 150 parts of water, and 4 parts of 3-mercaptopropionic acid as a chain transfer agent and 10% soda persulfate 40 parts of aqueous solution was dripped for 3 hours, and 10 parts of 10% sodium persulfate aqueous solution was dripped further for 1 hour after completion | finish of dripping. Then, the mixture was maintained at 80 ° C. for 1 hour to complete the polymerization reaction, and neutralized with 15 parts of 50% aqueous solution of caustic soda, thereby obtaining a cement admixture containing an aqueous solution of a copolymer having a weight average molecular weight of 24,800.

Example 8. Cement Mortar Test

The materials and cement mix used for the test are 1,200 g of Portland cement, 2,400 g of sand, and 480 g of water. The amount of admixture added is 1% by weight of solids based on cement, and the results are shown in Table 1 below.

Table 1. Cement Mortar Test Results

Example 9 Concrete Test

The materials and concrete mix used in the test were 400 kg of Portland cement, 765 kg of sand, 953 kg of coarse gravel, 100 kg of fly ash, and 162 kg of water. The amount of admixture added is 1.2% by weight of solids based on cement, and the results are shown in Table 2 below.

Table 2. Concrete Test Results

As described above, the cement and concrete admixture according to the present invention can increase the fluidity compared to the conventional water reducing agent to obtain a high sensitivity and slump even at a small amount of addition, can greatly improve workability, workability, hydration reaction It is a cement admixture made of a high molecular polymer that does not affect and can improve the strength and durability even after curing.

Claims (5)

In the esterification reaction of the polyoxyalkylene glycol compound represented by the general formula (7) to the general formula (6) which is a polycarboxylic acid polymer anhydride consisting of repeating units of the following general formulas (1), (2) and (5) Cement and concrete dispersants composed of the prepared polycarboxylic acid polymers or salts thereof. Repeating unit represented by general formula (1) (One) Wherein R ¹ and R ² are the same or different and represent a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, and R ³ represents a hydrogen atom, a phenyl group, an alkylphenyl group, a sulfonated phenyl group, an alkyl group of 1 to 30 carbon atoms, or a carbon number An alkenyl group of 2 to 30 or a selected organic group consisting of -OR ⁴ , -OCOR ⁵ , -X ¹ OR ⁶ , -0 (R ⁷ O) ₁ R ⁸ and -CN; R ⁴ , R ⁵ each represent 1 carbon atom. A hydrocarbon group of 30 to 30, X ¹ is a divalent hydrocarbon group having 1 to 3 carbon atoms, R ⁶ and R ⁸ are each a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms, and R ⁷ is an alkenyl having 2 to 30 carbon atoms Group, 1 represents the average mole number of the oxyalkylene group represented by-(R ⁷ O)-, and is a positive number of 1 to 300, p represents the appearance fraction (molar ratio) of repeating units in the polycarboxylic acid polymer and not 0. .) Repeating unit represented by general formula (2) (2) (Wherein R ⁹ is hydrogen or methyl group and M ¹ is hydrogen, monovalent metal, divalent metal, ammonium or organic ammonium, q represents the appearance fraction (molar ratio) of repeating units in the polycarboxylic acid polymer and 0 is no.) Repeating unit represented by general formula (5) (5) (Wherein u represents the appearance fraction (molar ratio) of repeating units in the polycarboxylic acid polymer and is not zero.) Polycarboxylic anhydride represented by general formula (6) (6) (Wherein R ¹ to R ⁹ , M ¹ are as defined above, p, q and u represent the molar ratio of repeating units in the polycarboxylic acid polymer and not 0). Polyoxyalkylene glycol compound represented by General formula (7) (7) Wherein R ₁₀ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, R ₁₁ O is composed of one or two or more mixtures of oxyalkylene groups having 2 to 4 carbon atoms, and in the case of two or more species, It may be added or may be added at random, m represents an integer of 1 to 100 in the average added mole number of the oxyalkylene group.) The cement and concrete dispersant according to claim 1, wherein the polycarboxylic acid polymer or salt thereof has an average molecular weight in the range of 10,000 to 300,000 and has the following repeating units. Repeating unit represented by general formula (1) (One) Wherein R ¹ and R ² are the same or different and represent a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, and R ³ represents a hydrogen atom, a phenyl group, an alkylphenyl group, a sulfonated phenyl group, an alkyl group of 1 to 30 carbon atoms, or a carbon number An alkenyl group of 2 to 30 or a selected organic group consisting of -OR ⁴ , -OCOR ⁵ , -X ¹ OR ⁶ , -O (R ⁷ O) ₁ R ⁸ and -CN: R ⁴ , R ⁵ are each 1 carbon number A hydrocarbon group of 30 to 30, X ¹ is a divalent hydrocarbon group having 1 to 3 carbon atoms, R ⁶ and R ⁸ are each a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms, and R ⁷ is an alkenyl having 2 to 30 carbon atoms Group, 1 represents the average mole number of the oxyalkylene group represented by-(R ⁷ O)-and is a positive number of 1 to 300, p represents the appearance fraction (molar ratio) of repeating units in the polycarboxylic acid polymer and is not 0. .) Repeating unit represented by general formula (2) (2) (Wherein R ⁹ is hydrogen or methyl group, M ¹ is hydrogen, monovalent metal, divalent metal, ammonium or organic ammonium, q represents the appearance fraction (molar ratio) of repeating units in the polycarboxylic acid polymer and 0 Not this.) Repeating unit represented by General formula (3) (3) Wherein M ² and M ³ are the same or different and may each have a hydrogen atom, an ammonium group or an organic amine group, and r is repeated in the polycarboxylic acid polymer The fraction of occurrence of the monomer (molar ratio), not zero.) Repeating unit represented by general formula (4) (4) (In the formula, -R ¹⁰ O- consists of one kind or a mixture of two or more kinds of oxyalkylene groups having 2 to 4 carbon atoms, and in the case of two or more kinds, may be added in block form or randomly added. R ¹¹ is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, M ⁴ is hydrogen, a monovalent metal, a divalent metal, ammonium or an organic ammonium, m is an integer of 1 to 100 as the average added mole number of the oxyalkylene group, s is Represents the appearance fraction (molar ratio) of repeating units in the polycarboxylic acid polymer and is not zero.) The alkoxy polyoxyalkylene group represented by General formula (6) in General formula (6) in manufacture of the polycarboxylic acid polymer by esterification of above-mentioned General formula (6) and General formula (7) of Claim 1 Cement and concrete admixtures (dispersants) produced by direct esterification. Of the alkoxypolyoxyalkylene group and the polyoxyalkylene group represented by the general formula (7) in the general formula (6), which is a polycarboxylic acid anhydride composed of the repeating units of the general formulas (1) (2) and (5) Cement and concrete dispersing agent which consists of a polycarboxylic acid polymer or its salt which reacted using 0.1-10 mol% of derivatives which have hydroxyl groups in both terminals with respect to alkoxy polyoxyalkylene. The cement and concrete dispersant according to claim 1, wherein the polydispersity of the polycarboxylic acid polymer or a salt thereof is 1 to 100.