KR20080081670A - Cement admixture, method for preparing the same, and cement composition containing the same - Google Patents

Abstract

A cement admixture is provided to impart good workability to a cement composition by improving hardening retardation and preventing a decline in flowability, and to form concrete having high early strength. A cement admixture includes a copolymer salt obtained by neutralizing a carboxylic acid copolymer with an ethanolamine-based or alkyldiethanolamine-based solution. The carboxylic acid copolymer is prepared by polymerizing (a) 50-95wt% of an alkoxypolyalkyleneglycolmono(meth)acrylic acid ester monomer represented by a formula 1, (b) 3-45wt% of a (meth)acrylic acid monomer represented by a formula 2 or salts thereof, and (c) 0.5-20wt% of a polyoxyalkylenealkenylether sulfate salt represented by a formula 3. In the formula 1, R^1 is a hydrogen atom or methyl, R^2O is one or a mixture of at least two selected from C2-4 oxyalkylene, and may be added in a block or random form in case of the mixture, R^3 is C1-4 alkyl, m is the average addition mole number of oxyalkylene groups, and is an integer of 50-200. In the formula 2, R^4 is a hydrogen atom or methyl, and M^1 is a hydrogen atom, monovalent metal, divalent metal, ammonium, or organic amine. In the formula 3, R^5 is a hydrogen atom or methyl, R^6 is C1-3 alkylene, phenylene, or alkylphenylene, R^7 is one or a mixture of at least two selected from C1-4 oxyalkylene, and may be added in a block or random form in case of the mixture, n is the average addition mole number of oxyalkylene groups and an integer of 10-50, and M^2 is a hydrogen atom, monovalent metal, ammonium, or organic amine.

Description

Cement admixtures, preparation methods thereof, and cement compositions comprising the same {CEMENT ADMIXTURE, METHOD FOR PREPARING THE SAME, AND CEMENT COMPOSITION CONTAINING THE SAME}

The present invention relates to a cement admixture, and more particularly, to improve initial susceptibility due to excellent initial dispersibility compared to conventional cement admixtures, improve flowability of the composition even in a region of high susceptibility, and improve curing delay. The present invention relates to a cement admixture, a method for preparing the same, and a cement composition including the same, wherein the cement admixture is capable of forming a concrete having high strength by providing good workability to the cement composition by preventing a decrease in fluidity while simultaneously exhibiting strength.

Cement compositions, such as concrete or mortar, are hydraulic reactants that are cured by the reaction of cement and water, and have different physical properties such as compressive strength after curing depending on the amount of water used. In general, the increase in the amount of water used improves the workability, but decreases the compressive strength and causes cracks. Therefore, the amount of water used for the cement composition is limited, and in accordance with Korean Industrial Standard KS F 2560 to reduce the amount of water. The chemical admixture for concrete is used as mentioned later.

The types of chemically synthesized admixtures are roughly classified into air entraining admixtures, water reducing admixtures, and high range water reducing admixtures. In addition, AE, which is a chemical admixture used in cement compositions to increase the amount of fine air, is mixed with a water reducing agent or a high performance water reducing agent and classified into an air entraining and water reducing admixture and a high performance AE water reducing agent. The ability of the AE water reducing agent to reduce water can reduce water usage by as much as 10% by weight, while the high performance AE water reducing agent can reduce by more than 18% by weight.

The concrete in the cement composition usually had a slump drop after 30 minutes and had to finish all the work in a short time from concrete mixing to casting. In response to the recent trend of increasing the number of units due to the deterioration of the quality of concrete aggregates, the use of modern mechanized equipment and traffic congestion have a higher sensitivity than conventional AE water reducing agents, or a chemical admixture with excellent slump retention performance Has been required. As a admixture of hydraulic compositions such as cement and concrete, it has a high sensitivity and fluidity, and has an excellent slump retention, and is currently naphthalene sulfonic acid formaldehyde condensate salt (naphthalene-based), melamine sulfonic acid formaldehyde condensate salt (melamine), poly High performance AE water reducing agents, such as a carboxylic acid salt (polycarboxylic acid type), are used.

Each of these high performance sensitizers has excellent features, but there are also problems. For example, naphthalene-based or melamine-based have excellent curing properties but have problems in flow retention (slump loss), whereas polycarboxylic acids have advantages in that very good fluidity and retention can be obtained with only a small amount of addition. The problem is that the delay is large.

In recent years, cement admixtures have been developed that improve the problem of delayed curing of polycarboxylic acid-based water-reducing agents, exhibit high susceptibility and sufficient fluidity, and also express high strength early by shortening the setting time to enable high workability and shorten construction period. Has been. In particular, since the mid-1990s, water-soluble vinyl copolymer high performance AE water reducing agents having excellent dispersion characteristics using the steric repulsion of oxyalkylene groups and shortening the setting time have been proposed. Examples of such vinyl copolymers include copolymers of polyalkylene glycol mono (meth) acrylic acid ester monomers and dicarboxylic acid monomers such as (meth) acrylic acid or maleic acid.

Japanese Patent Application Laid-open No. Hei 8-12396 et al. Discloses a correlation between the cure delay of an polycarboxylic acid-based concrete admixture and an oxyalkylene group, and an oxyalkylene group added to a polyalkylene glycol mono ester monomer is specified in a specific range. It describes that the curing property is excellent. These cement admixtures have an effect of improving curing delay to some extent by increasing the number of moles of alkylene oxide compared with conventional polycarboxylic acid admixtures, but the slump retention is not satisfactory and the early strength properties are not sufficient yet. As a result, more performance is required.

In addition, Japanese Patent Application Laid-open No. Hei 9-132445 discloses a cement admixture composed of a polymer of a diester monomer to which 2 to 300 moles of an oxyalkylene group is added and a dicarboxylic acid monomer of maleic acid. JP-A-9-241057 discloses a cement admixture in which the terminal of a polyalkylene glycol monomer to which an oxyalkylene group is added in the range of 100 to 300 moles is composed of an alkyl phenol group. This kind of water reducing agent has to be added in a large amount in order to exhibit sufficient dispersibility and slump retention, and the problem that the fluidity of the cement composition decreases rapidly with time in comparison with the effect of reducing the curing delay has not been solved.

Japanese Patent Application Laid-Open No. 11-157897 discloses two types of polyalkylene glycol (meth) acrylic acid ester monomers each having an added molar number of 80 to 300 moles and 5 to 30 moles of an oxyalkylene group, and (meth) Disclosed is a copolymer cement admixture having an acrylic acid salt or a dicarboxylic acid monomer as an essential component and improving curing delay without increasing the viscosity.

Although the water reducing agent composed of the above water-soluble vinyl copolymer has an effect of reducing the curing delay of the cement composition to shorten the construction period, in order to shorten the setting time, the added mole number of the oxyalkylene group is too high, and the initial susceptibility is excellent. A large amount of addition is required in order for the slump holding force of the cement composition to drop rapidly to maintain sufficient dispersibility. Therefore, in order to improve the delay of the curing time to express the work strength early and to satisfy the excellent slump holding force, further performance is required.

In order to solve the problems of the prior art as described above, the present invention is a copolymer salt obtained by further neutralizing with an ethanolamine-based or alkyl diethanolamine-based solution is superior in initial dispersibility compared to conventional cement admixtures to improve the initial susceptibility It improves the fluidity of the composition even in the region of high susceptibility, improves the cure delay and expresses the strength early and prevents the fluidity deterioration, thereby giving the cement composition good workability to form concrete having high strength early. It is an object of the present invention to provide a cement admixture, and a method for producing the same.

It is another object of the present invention to provide a cement composition comprising the cement admixture.

The above and other objects of the present invention can be achieved by the present invention described below.

In order to achieve the above object, the present invention

a) 50 to 95% by weight of an alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer represented by Formula 1;

b) 3 to 45 wt% of a (meth) acrylic acid monomer represented by Formula 2 or a salt thereof; And

c) a copolymer salt obtained by neutralizing a carboxylic acid-based copolymer polymerized from 0.5 to 20% by weight of a polyoxyalkylene alkenylether sulfate salt represented by the following formula (3) with an ethanolamine-based or alkyldiethanolamine-based solution A cement admixture, and a method for producing the same, are provided.

[Formula 1]

In Chemical Formula 1,

R ¹ is a hydrogen atom or methyl,

R ² O is one or a mixture of two or more oxyalkylenes having 2 to 4 carbon atoms, and in the case of two or more, may be added in a block or random phase,

R ³ is alkyl having 1 to 4 carbons,

m is an integer of 50 to 200 in the average added mole number of the oxyalkylene group;

[Formula 2]

In Chemical Formula 2,

R ⁴ is a hydrogen atom or methyl,

M ¹ is represented by a hydrogen atom, a monovalent metal, a divalent metal, ammonium, or an organic amine;

[Formula 3]

In Chemical Formula 3,

R ⁵ is a hydrogen atom or methyl,

R ⁶ is alkylene, phenylene or alkylphenylene having 1 to 3 carbon atoms,

R ⁷ is one kind or a mixture of two or more kinds of oxyalkylenes having 1 to 4 carbon atoms, and in the case of two or more kinds, R ⁷ may be added in a block or random phase,

n is an integer of 10 to 50 as the average added mole number of the oxyalkylene group,

M ² is a hydrogen atom, a monovalent metal, ammonium or an organic amine.

In another aspect, the present invention provides a cement composition comprising 0.01 to 10 parts by weight of the cement admixture based on 100 parts by weight of cement.

Hereinafter, the present invention will be described in detail.

The present inventors add and copolymerize a polyoxyalkylene alkenylether sulfate salt, which is a reactive surfactant, as a unit monomer to a copolymer based on a carboxylic acid monomer, and further neutralize it with an ethanolamine-based or alkyldieethanolamine-based solution. It is a cement admixture prepared from the copolymer salt obtained by the present invention. It is possible to shorten the construction period, prevent the time-dependent deterioration of the fluidity, and at the same time, confirm that the cement composition is provided with good workability by continuously running an appropriate amount of air, thereby completing the present invention.

Copolymer salt of the present invention is a) 50 to 95% by weight of alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer represented by the formula (1), b) (meth) acrylic acid monomer represented by the formula (2) or salts thereof To 45% by weight, and c) a copolymer obtained by further neutralizing the copolymer polymerized from 0.5 to 20% by weight of the polyoxyalkylene alkenylether sulfate salt represented by Chemical Formula 3 with an ethanolamine-based or alkyldieethanolamine-based solution. Salt.

A) The alkoxy polyalkylene glycol mono (meth) acrylic acid ester monomer represented by Formula 1 is methoxy polyethylene glycol mono (meth) acrylate, methoxypolypropylene glycol mono (meth) acrylate, methoxypolybutylene glycol Mono (meth) acrylate, methoxy polyethylene glycol polypropylene glycol mono (meth) acrylate, methoxy polyethylene glycol polybutylene glycol mono (meth) acrylate, methoxy polypropylene glycol polybutylene glycol mono (meth) acryl Ethylene Polyethylene Glycol Mono (meth) acrylate, Ethoxy Polypropylene Glycol Mono (meth) acrylate, Ethoxy Polybutylene Glycol Monohydrate (Meth) acrylate, ethoxy polyethylene glycol polypropylene glycol mono (meth (2) acrylate, ethoxy polyethylene glycol polybutylene glycol mono (meth) acrylate, ethoxy polypropylene glycol polybutylene glycol mono (meth) acrylate, or ethoxy polyethylene glycol polypropylene glycol polybutylene glycol mono ( Methacrylate, etc. may be selected, and these may be copolymerized alone or in mixture of two or more kinds.

It is preferable that the average added mole number of an oxyalkylene group is an integer of 50-200, and, as for the monomer represented by said a) General formula (1), More preferably, it is 50-150. When the average added mole number of the oxyalkylene group is 50 to 200, there is an effect of improving the initial susceptibility, improving the curing delay, and expressing high strength at an early stage.

The a) monomer represented by Formula 1 is preferably included in the carboxylic acid-based copolymer in 50 to 95% by weight. When included in the content has an excellent dispersibility.

B) As the (meth) acrylic acid monomer represented by Formula 2, acrylic acid, methacrylic acid, and monovalent metal salts, divalent metal salts, ammonium salts, and organic amine salts of these acids may be selected, and these may be used alone or in combination. More than one species may be mixed and copolymerized.

B) The monomer represented by the formula (2) is preferably included in the carboxylic acid copolymer 3 to 45% by weight. When included in the content has the effect of improving the slump loss preventing ability of the cement composition.

C) The polyoxyalkylene alkenyl ether sulfate salt represented by Chemical Formula 3 is a reactive surfactant included as a unit monomer in the carboxylic acid-based copolymer, which has both a hydrophobic group and a hydrophilic group to increase the water solubility of the polymer, Increased the number of moles of alkylene oxide groups added to the polyalkylene glycol ester monomers in order to accelerate the settling time by increasing the properties that can cause physical adsorption. It suppresses the deterioration of fluidity of the cement composition generated over time to maintain the slump retention.

In addition, c) the polyoxyalkylene alkenyl ether sulfate salt represented by the formula (3) has a double bond that can participate in the radical reaction is copolymerized with the monomers to act as a surfactant in the polymer backbone. The hydrophobic portion of these surfactants aids in the adsorption of cement particles, while the ionic portion forms an electrical double layer to increase zeta potential and increase electrostatic repulsion and stability between dispersed particles. Therefore, the hydrophilicity of the polyalkylene glycol chain and the effect of dispersing the cement due to steric repulsion as well as the electrostatic repulsion by the sulfonic acid at the end of the surfactant at the same time is more excellent in dispersion and stability of entrained air.

C) As the polyoxyalkylene alkenyl ether sulfate salt represented by the formula (3), sulfoxypolyethylene glycol nonylphenylpropenyl ether, sulfoxy polyethylene glycol allyl ether, sulfoxy polypropylene glycol allyl ether, sulfoxy polybutylene glycol allyl Ether, sulfoxy polyethylene glycol 2-butenyl ether, sulfoxy polypropylene glycol 2-butenyl ether, sulfoxy polybutylene glycol 2-butenyl ether, sulfoxy polyethylene glycol 3-butenyl ether, sulfoxy polypropylene glycol 3-butenyl ether, sulfoxy polybutylene glycol 3-butenyl ether, sulfoxy polyethylene glycol 3-pentenyl ether, sulfoxy polypropylene glycol 3-pentenyl ether, sulfoxy polybutylene glycol 3-pentenyl ether Sulfoxy polyalkylene glycol allyl ethers such as these; Sulfoxypolyethylene glycol (3-vinyl-5-methyl) phenyl ether, sulfoxypolypropylene glycol (3-vinyl-5-methyl) phenyl ether, sulfoxypolybutylene glycol (3-vinyl-5-methyl) phenyl ether , Sulfoxypolyethylene glycol (3-vinyl-5-ethyl) phenyl ether, sulfoxypolypropylene glycol (3-vinyl-5-ethyl) phenyl ether, sulfoxypolybutylene glycol (3-vinyl-5-ethyl) phenyl Ether, sulfoxypolypropylene glycol (3-propenyl-5-propyl) phenyl ether, sulfoxypolybutylene glycol (3-propenyl-5-propyl) phenyl ether, sulfoxypolyethylene glycol (3-propenyl-5 Sulfoxypolyalkylene glycols such as -butyl) phenyl ether, sulfoxypolypropylene glycol (3-propenyl-5-butyl) phenyl ether and sulfoxypolybutylene glycol (3-propenyl-5-butyl) phenyl ether Alkyl vinyl phenyl ethers; 2-sulfoxypolyethylene glycol-3- (4-methylphenoxy) propylene allyl ether, 2-sulfoxy polypropylene glycol-3- (4-methylphenoxy) propylene ether, 2-sulfoxypolybutylene glycol-3 -(4-methylphenoxy) propylene allyl ether, 2-sulfoxypolyethylene glycol-3- (4-ethylphenoxy) propylene allyl ether, 2-sulfoxy polypropylene glycol-3- (4-ethylphenoxy) propylene 2-sulfoxypolyalkylene glycol-3- (4-alkylphenoxy) propylene allyl ethers such as allyl ether and 2-sulfoxypolybutylene glycol-3- (4-ethylphenoxy) propylene allyl ether; And those neutralized with monovalent metals, divalent metals, ammonium salts or organic amines, and the like, and these may be copolymerized alone or in combination of two or more thereof.

C) The polyoxyalkylene alkenyl ether sulfate salt represented by Formula 3 is preferably included in the carboxylic acid-based copolymer in 0.1 to 20% by weight. When it is included in the content, there is an excellent effect of the slump holding force and the appropriate air entrainment capacity of the cement composition.

The salt of the copolymer of the present invention is a copolymer salt obtained by further neutralizing the carboxylic acid-based copolymer with various alkaline substances, ethanolamine-based or alkyldiethanolamine-based solutions.

The ethanolamine-based or alkyl diethanolamine-based solution may be selected from at least one neutralizing solution consisting of ethanolamine, diethanolamine, triethanolamine, methyl diethanolamine, ethyl diethanolamine and butyl diethanolamine, Preferably triethanolamine or methyldiethanolamine.

The copolymer salt preferably has a weight average molecular weight of 30,000 to 100,000 when measured by GPC (Gel Permeation Chromatography), and more preferably 30,000 to 70,000 in view of dispersibility. In the case of the weight average molecular weight, it is excellent in initial dispersibility to improve the initial susceptibility, not only to maintain the slump retention of the composition, but also to improve the curing delay to form a concrete composition having a high strength early.

Examples of the copolymer salt containing the polyoxyalkylene alkenyl ether sulfate salt of the present invention as a unit monomer may be a copolymer represented by the following Chemical Formulas 4a and 4b, but are not limited thereto.

[Formula 4a]

[Formula 4b]

In Chemical Formulas 4a and 4b,

M is hydrogen or a monovalent or divalent metal, m, m ', n, o, p, q, and r represent the number of moles, and at least one of m, m' is not 0, and among o, p At least one is not zero and n, q and r cannot be zero.

Method for producing a copolymer salt of the present invention is a) 50 to 95% by weight of the alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer represented by the formula (1), (meth) acrylic acid monomer represented by the formula (2) or salts thereof To 45% by weight, and 0.5 to 20% by weight of a polyoxyalkylene alkenylether sulfate salt represented by Chemical Formula 3, copolymerizing under a polymerization initiator; And b) neutralizing the prepared copolymer with an ethanolamine-based or alkyldiethanolamine-based solution.

The copolymerization method is not particularly limited, and methods such as solution polymerization or bulk polymerization can be used.

When the polymerization initiator is polymerized using water as a solvent, a water-soluble polymerization initiator such as ammonium or an alkali metal persulfate or hydrogen peroxide may be used as a solution polymerization initiator. In addition, in the case of polymerization using a lower alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester compound or a ketone compound as a solvent, hydroperoxides such as benzoyl peroxide, lauroyl peroxide, cumene hydroperoxide, or azobisisobutyronitrile Polymerization initiators, such as aliphatic azo compounds, can be used, and at this time, accelerators, such as an amine compound, can be used together. Moreover, when superposing | polymerizing using a water-lower alcohol mixed solvent, it can select suitably from the said polymerization initiator or the combination of a polymerization initiator and an accelerator, and can use.

The polymerization initiator is preferably used in 0.5 to 5% by weight based on the total monomer content.

It is preferable to select the polymerization temperature of the said copolymerization reaction in the range of 0-120 degreeC according to the kind of solvent and polymerization initiator to be used.

In the copolymerization reaction, a thiol-based chain transfer agent may be used together to control the molecular weight of the carboxylic acid-based copolymer prepared. As the thiol-based chain transfer agent, mercapto ethanol, thioglycerol, thioglycolic acid, 2-mercapto propionic acid, 3-mercapto propionic acid, thiosaplic acid, thioglycolic acid octyl, or 3-mercapto propionic acid octyl or the like alone or two. It can mix and use species. The thiol-based chain transfer agent is preferably used in 0.5 to 5% by weight based on the total monomer content.

The carboxylic acid-based copolymer prepared by the above method uses a copolymer salt obtained by neutralization with an ethanolamine-based or alkyldiethanolamine-based solution as a main component of the cement admixture.

The cement composition of the present invention comprises cement and the cement admixture prepared above.

The admixture is preferably included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of cement, and in particular, 0.1 to 5 parts by weight is more preferable in consideration of the region of high susceptibility. When the amount is included in the above content, dispersibility, water resistance, air entrainment, etc. are exerted depending on the content, and are economically preferable.

Cement admixture of the present invention exhibits a high susceptibility to improve the dispersibility of cement particles in concrete to reduce the amount of water used by more than 18% by weight, improve the fluidity of the composition even in the region of high susceptibility, and the conventional polycarboxylic acid system Compared with the admixture, the curing delay is greatly improved, and the cement composition exhibits the early working strength, but the fluidity decreases little with time, and the appropriate amount of air is continuously operated, which is good for the cement composition. It has the feature of forming concrete with high strength while providing workability.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

EXAMPLE

Example  One

200 parts by weight of water was injected into a 2 L capacity glass reactor equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen introduction tube and a reflux condenser, and the reaction vessel was replaced with nitrogen and heated to 80 ° C. under a nitrogen atmosphere under stirring.

After adding 2 parts by weight of ammonium persulfate to the reactor and completing the preparation, 300 parts by weight of methoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide (EO) added 55 mol), 49.8 parts by weight of methacrylic acid, Monomer aqueous solution and 3-mer mixed with 3.5 parts by weight of polyoxyethylene nonylphenyl propenyl ether sulfate ammonium salt (average number of moles of ethylene oxide (EO)) and 95 parts by weight of water as nonionic and anionic reactive surfactant 4.7 parts by weight of captopropionic acid and 60 parts by weight of water were mixed, and 80 parts by weight of a 3% by weight aqueous ammonium persulfate solution was added dropwise for 4 hours. After completion of the dropwise addition, 10 parts by weight of an aqueous solution of ammonium persulfate at a concentration of 3% by weight was added at once. Thereafter, the temperature was kept at 80 ° C. for 1 hour to complete the polymerization reaction.

After the polymerization was completed, the mixture was cooled to room temperature and then neutralized with an aqueous solution of triethanolamine (TEA) at a concentration of 30% by weight for about 1 hour. The salt of the water-soluble copolymer prepared as described above showed a weight average molecular weight of 35,000 measured by Gel Permeation Chromatography (GPC).

Example  2

The polymerization was carried out in the same manner as in Example 1, except that the polymerization was completed in Example 1 and then cooled to room temperature and then neutralized with an aqueous solution of methyl diethanolamine (MDEA) at a concentration of 30 wt% for about 1 hour.

The salt of the prepared water-soluble copolymer exhibited a weight average molecular weight of 35,000 measured by Gel Permeation Chromatography (GPC).

Example  3

310 parts by weight of methoxy polyethylene glycol monomethacrylate (average number of moles of ethylene oxide (EO) added), 38.3 parts by weight of methacrylic acid, polyionic and anionic reactive surfactant as the polymerization composition in Example 1 It carried out by the same method as Example 1 except having used the aqueous monomer solution which mixed 3.6 weight part of oxyethylene nonylphenyl propenyl ether sulfate ammonium salt (10 mol of average added moles of ethylene oxide (EO)), and 95 weight part of water. It was.

The salt of the prepared water-soluble copolymer exhibited a weight average molecular weight of 39,000 measured by GPC (Gel Permeation Chromatography) method.

Example  4

The polymerization was carried out in the same manner as in Example 3, except that the polymerization was completed in Example 3 and then cooled to room temperature and then neutralized with an aqueous solution of methyldiethanolamine at a concentration of 30% by weight for about 1 hour.

The salt of the prepared water-soluble copolymer exhibited a weight average molecular weight of 39,000 measured by GPC (Gel Permeation Chromatography) method.

Example  5

As the polymerization composition in Example 1, 320 parts by weight of methoxy polyethylene glycol monomethacrylate (110 moles of an average added mole number of ethylene oxide (EO)), 19.7 parts by weight of methacrylic acid, a polyionic and anionic reactive surfactant Oxyethylene nonylphenyl propenyl ether sulfate ammonium salt (average added mole number 10 mol of ethylene oxide (EO)) 3.4 parts by weight, except that a monomer aqueous solution mixed with 95 parts by weight of water was used in the same manner as in Example 1 It was.

The salt of the prepared water-soluble copolymer exhibited a weight average molecular weight of 43,500 measured by GPC (Gel Permeation Chromatography) method.

Example  6

The polymerization was carried out in the same manner as in Example 5, except that the polymerization was completed in Example 5 and then cooled to room temperature and then neutralized with an aqueous solution of methyldiethanolamine at a concentration of 30% by weight for about 1 hour.

The salt of the prepared water-soluble copolymer exhibited a weight average molecular weight of 43,500 measured by GPC (Gel Permeation Chromatography) method.

Comparative example  One

The polymerization was carried out in the same manner as in Example 1 except that the polymerization was completed in Example 1 and then cooled to room temperature and then neutralized with an aqueous 30% by weight sodium hydroxide solution for about 1 hour.

The salt of the prepared water-soluble copolymer exhibited a weight average molecular weight of 35,000 measured by Gel Permeation Chromatography (GPC).

Comparative example  2

Naphthalene acid formaldehyde condensate (NSF, 40% solids) used as a conventional cement admixture was used.

The main components, contents and properties of the water-soluble copolymer salts prepared in Examples 1 to 6 and Comparative Example 1 are shown in Table 1 below.

  division Polyalkylene glycol (meth) acrylate Carboxylic Acid (Methacrylic Acid / Acrylic Acid) Reactive surfactant Solid content of copolymer salt (% by weight) Weight average molecular weight corrector EO confiscation Copolymer Content (% by weight) Copolymer Content (% by weight) Copolymer Content (wt%) Example 1 55 84.9 14.1 1.0 40.2 35,000 TEA Example 2 55 84.9 14.1 1.0 40.2 35,000 MDEA Example 3 80 88.1 10.9 1.0 40.1 39,000 TEA Example 4 80 88.1 10.9 1.0 40.1 39,000 MDEA Example 5 110 93.3 5.7 1.0 40.2 43,500 TEA Example 6 110 93.3 5.7 1.0 40.2 43,500 MDEA Comparative Example 1 55 84.9 14.1 1.0 40.2 35,000 NaOH

[Test Example]

The water-soluble copolymer salts of Examples 1 to 6 and Comparative Example 1 and the cement admixture of Comparative Example 2 were tested by the following methods, and the results are shown in Table 2 below.

* Concrete test-Cement was used as one type of ordinary Portland cement (manufactured by Hyundai Cement Co., Ltd.), fine aggregate was used for Incheon washing sand and crushed sand, and coarse aggregate was used for 25 mm crushed aggregate. In addition, cement, fine aggregate, coarse aggregate, and mixed water reflecting the seasonal factors of concrete construction were stored and used in a constant temperature and humidity room one day before the experiment at low temperature (10 ° C). The cement admixtures prepared in Examples and Comparative Examples were respectively kneaded by mixing 0.4 wt% of the cement weight (binder) (0.8 wt% in Comparative Example 2) to prepare concrete.

 division W / B (wt%) S / A (% by volume) Unit material amount (kg / ㎥) Admixture W C F / A S1 S2 G Usage (B ×%) Examples 1-6 Comparative Examples 1-2 42.5 47.0 154 330 33 417 433 933 0.4

After each concrete is measured for slump and air volume, the test agent is added to the molding mold according to the Korean Industrial Standard KS F 2402 and KS F 2449 method, and stored at 10 ℃. The compressive strength (MPa) of the test agent was measured.

  division Added amount (% by weight of binder)  Concrete Slump (cm)  Air volume (%)  Compressive strength (MPa) and strength expression rate (% of design reference strength 24MPa) Concrete admixture Early 60 minutes Early 60 minutes 16 hours 19 hours 36 hours 42 hours 72 hours Example 1 0.4 21.0 18.0 6.2 4.1 0.4 0.9 7.6 8.9 18.0 1.7% 3.8% 31.7% 37.1% 75.0% Example 2 0.4 21.0 18.5 5.7 3.9 0.5 1.0 7.6 9.4 19.6 2.1% 4.2% 31.7% 39.2% 81.7% Example 3 0.4 20.5 19.5 6.1 4.2 0.5 1.2 8.0 10.7 19.8 2.1% 5.0% 33.3% 44.6% 82.5% Example 4 0.4 21.0 20.0 5.8 3.8 0.7 1.4 8.3 11.3 20.9 2.9% 5.8% 34.6% 47.1% 87.1% Example 5 0.4 20.0 13.0 6.0 4.3 0.5 1.2 6.8 9.3 18.1 2.1% 5.0% 28.3% 38.8% 75.4% Example 6 0.4 20.5 16.0 5.9 4.1 0.6 1.3 7.8 9.8 19.2 2.5% 5.4% 32.5% 40.8% 80.0% Comparative Example 1 0.4 20.0 18.0 6.0 4.5 0.3 0.8 6.5 7.6 15.0 1.3% 3.3% 27.1% 31.7% 62.5% Comparative Example 2 0.8 22.0 11.5 6.0 3.9 0.4 0.5 5.1 7.3 16.7 1.7% 2.1% 21.3% 30.4% 69.6%

As shown in Table 2, it was found that the concrete to which the cement admixtures of Examples 1 to 6 according to the present invention is applied has a superior concrete slump holding force as compared to Comparative Examples 1 to 2, and the deterioration of fluidity of the cement composition with time is reduced. Rarely.

In the cement compositions of Examples 1 and 2, the fluidity deterioration with time was 14.3% and 11.9%, respectively. In the case of Examples 3 and 4, the fluidity deterioration with time was improved to 5.0%, so that the performance of polyalkylene glycol was improved. The increase in the average added mole number of ethylene oxide of (meth) acrylate is slightly lower in initial dispersibility, but compared with the conventional cement admixture (Comparative Example 2), the retention performance is greatly improved, showing excellent performance in preventing fluidity deterioration of the cement composition. It can be seen that.

As shown in Table 2, the initial air amount distribution of the cement composition was 5.7 to 6.2% in both Examples 1 to 6 and Comparative Examples 1 and 2 according to the present invention, which was slightly higher than the target air amount, but the appropriate amount of air was distributed. . The reason for exceeding the target air volume is because concrete is manufactured under the same conditions as winter construction conditions and the temperature of concrete is low. In addition, it can be seen that the air amount contributed to the improvement of the flow characteristics by the ball bearing action by generating a stable fine bubble in the above-mentioned cement composition. The distribution of air volume over time is slightly reduced due to the decrease of the concentration of AE agent in cement paste by adsorbing AE agent to unburned carbon of fly ash by use of fly ash. The retention performance was found to be very good.

When comparing the Examples 1 to 6 performed to compare the characteristics of early strength after 16 hours of age at curing temperature 10 ℃, compared with the concrete of the general strength Comparative Examples 1 to 2, the strength is expressed by more than 50% by the time of strength measurement Showed characteristics. In particular, concrete compositions (Examples 2, 4 and 6) using carboxylic acid-based copolymer salts neutralized with methyldiethanolamine resulted in an increase in the average added mole number of ethylene oxide (EO) and the weight average molecular weight. It showed a relatively high strength compared to the concrete composition (Examples 1, 3, 5) using the carboxylic acid-based copolymer salt neutralized by. It is believed that the carboxylic acid-based copolymer salt accelerated the production rate of ettringite and resulted in premature condensation by densely producing the shape of ethringite. Such strength expression characteristics are shown to amplify the effect as the age is increased in Examples 3 and 4. This cement admixture of the present invention improves the dispersibility of the cement particles and at the same time increases the retention properties, and even with a small amount of content, excellent water-resistance effect gives good workability and at the same time introduces a high mole number of oxyalkylene groups The salt of the copolymer obtained by neutralizing one carboxylic acid-based copolymer with an optimal alkaline material was able to secure the required strength early by promoting the condensation and curing of the concrete composition immediately after lapse of 1 hour.

As described above, according to the present invention, a copolymer salt obtained by further neutralizing a carboxylic acid-based copolymer having a high molar number of oxyalkylene groups with an ethanolamine-based or alkyldieethanolamine-based solution is compared with conventional cement admixtures. Excellent initial dispersibility improves initial susceptibility, improves fluidity of composition even in the region of high susceptibility, improves cure delay, gives strength at early stage, and prevents deterioration of fluidity. Thus, there is an effect of providing a cement admixture to form concrete having high strength early.

Claims (11)

a) 50 to 95 wt% of an alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer represented by Formula 1 below, b) 3 to 45 wt% of a (meth) acrylic acid monomer represented by Formula 2 below or a salt thereof; And c) a copolymer salt obtained by neutralizing a carboxylic acid-based copolymer polymerized from 0.5 to 20% by weight of a polyoxyalkylene alkenylether sulfate salt represented by Formula 3 with an ethanolamine-based or alkyldieethanolamine-based solution. A cement admixture, characterized in that; [Formula 1]

In Chemical Formula 1, R ¹ is a hydrogen atom or methyl, R ² O is one or a mixture of two or more oxyalkylenes having 2 to 4 carbon atoms, and in the case of two or more, may be added in a block or random phase, R ³ is alkyl having 1 to 4 carbons, m is an integer of 50 to 200 in the average added mole number of the oxyalkylene group; [Formula 2]

In Chemical Formula 2, R ⁴ is a hydrogen atom or methyl, M ¹ is represented by a hydrogen atom, a monovalent metal, a divalent metal, ammonium, or an organic amine; [Formula 3]

In Chemical Formula 3, R ⁵ is a hydrogen atom or methyl, R ⁶ is alkylene, phenylene or alkylphenylene having 1 to 3 carbon atoms, R ⁷ is one kind or a mixture of two or more kinds of oxyalkylenes having 1 to 4 carbon atoms, and in the case of two or more kinds, R ⁷ may be added in a block or random phase, n is an integer of 10 to 50 as the average added mole number of the oxyalkylene group, M ² is a hydrogen atom, a monovalent metal, ammonium or an organic amine. The method of claim 1, A) The alkoxy polyalkylene glycol mono (meth) acrylic acid ester monomer represented by Formula 1 is methoxy polyethylene glycol mono (meth) acrylate, methoxypolypropylene glycol mono (meth) acrylate, methoxypolybutylene glycol Mono (meth) acrylate, methoxy polyethylene glycol polypropylene glycol mono (meth) acrylate, methoxy polyethylene glycol polybutylene glycol mono (meth) acrylate, methoxy polypropylene glycol polybutylene glycol mono (meth) acryl Ethylene Polyethylene Glycol Mono (meth) acrylate, Ethoxy Polypropylene Glycol Mono (meth) acrylate, Ethoxy Polybutylene Glycol Monohydrate (Meth) acrylate, ethoxy polyethylene glycol polypropylene glycol mono (meth ) Acrylate, ethoxy polyethylene glycol polybutylene glycol mono (meth) acrylate, ethoxy polypropylene glycol polybutylene glycol mono (meth) acrylate, and ethoxy polyethylene glycol polypropylene glycol polybutylene glycol mono (meth) Cement admixture, characterized in that at least one selected from the group consisting of acrylates. The method of claim 1, B) The (meth) acrylic acid monomer represented by Formula 2 is selected from the group consisting of acrylic acid, methacrylic acid, and monovalent metal salts, divalent metal salts, ammonium salts, and organic amine salts of these acids. Cement admixture. The method of claim 1, C) Polyoxyalkylene alkenyl ether sulfate salt represented by the formula (3) is sulfoxy polyethylene glycol nonyl phenyl propenyl ether, sulfoxy polyethylene glycol allyl ether, sulfoxy polypropylene glycol allyl ether, sulfoxy polybutylene glycol allyl ether , Sulfoxy polyethylene glycol 2-butenyl ether, sulfoxy polypropylene glycol 2-butenyl ether, sulfoxy polybutylene glycol 2-butenyl ether, sulfoxy polyethylene glycol 3-butenyl ether, sulfoxy polypropylene glycol 3 -Butenyl ether, sulfoxy polybutylene glycol 3-butenyl ether, sulfoxy polyethylene glycol 3-pentenyl ether, sulfoxy polypropylene glycol 3-pentenyl ether, or sulfoxy polybutylene glycol 3-pentenyl ether Sulfoxy polyalkylene glycol allyl ethers; Sulfoxypolyethylene glycol (3-vinyl-5-methyl) phenyl ether, sulfoxypolypropylene glycol (3-vinyl-5-methyl) phenyl ether, sulfoxypolybutylene glycol (3-vinyl-5-methyl) phenyl ether , Sulfoxypolyethylene glycol (3-vinyl-5-ethyl) phenyl ether, sulfoxypolypropylene glycol (3-vinyl-5-ethyl) phenyl ether, sulfoxypolybutylene glycol (3-vinyl-5-ethyl) phenyl Ether, sulfoxypolypropylene glycol (3-propenyl-5-propyl) phenyl ether, sulfoxypolybutylene glycol (3-propenyl-5-propyl) phenyl ether, sulfoxypolyethylene glycol (3-propenyl-5 Sulfoxypolyalkylene glycols of -butyl) phenyl ether, sulfoxypolypropylene glycol (3-propenyl-5-butyl) phenyl ether, or sulfoxypolybutylene glycol (3-propenyl-5-butyl) phenyl ether Alkyl vinyl phenyl ethers; 2-sulfoxypolyethylene glycol-3- (4-methylphenoxy) propylene allyl ether, 2-sulfoxy polypropylene glycol-3- (4-methylphenoxy) propylene ether, 2-sulfoxypolybutylene glycol-3 -(4-methylphenoxy) propylene allyl ether, 2-sulfoxypolyethylene glycol-3- (4-ethylphenoxy) propylene allyl ether, 2-sulfoxy polypropylene glycol-3- (4-ethylphenoxy) propylene 2-sulfoxypolyalkylene glycol-3- (4-alkylphenoxy) propylene allyl ethers of allyl ether or 2-sulfoxypolybutylene glycol-3- (4-ethylphenoxy) propylene allyl ether; And A cement admixture selected from the group consisting of monovalent metals, divalent metals, ammonium salts, and salts neutralized with organic amines, respectively. The method of claim 1, The ethanolamine-based or alkyldiethanolamine-based solution is a neutralizing agent solution selected from the group consisting of ethanolamine, diethanolamine, triethanolamine, methyl diethanolamine, ethyl diethanolamine and butyl diethanolamine. Cement admixture made with. The method of claim 1, Salt of the copolymer is a cement admixture, characterized in that the weight average molecular weight of 30,000 to 100,000. a) 50 to 95 wt% of the alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer represented by the following formula (1), and 3 to 45 wt% of the (meth) acrylic acid monomer represented by the following formula (2) or a salt thereof; And copolymerizing 0.5 to 20% by weight of a polyoxyalkylene alkenylether sulfate salt represented by Chemical Formula 3 under a polymerization initiator; And b) neutralizing the prepared copolymer with an ethanolamine-based or alkyldiethanolamine-based solution; Method for producing a cement admixture comprising a; [Formula 1]

In Chemical Formula 1, R ¹ is a hydrogen atom or methyl, R ² O is one or a mixture of two or more oxyalkylenes having 2 to 4 carbon atoms, and in the case of two or more, may be added in a block or random phase, R ³ is alkyl having 1 to 4 carbons, m is an integer of 50 to 200 in the average added mole number of the oxyalkylene group; [Formula 2]

In Chemical Formula 2, R ⁴ is a hydrogen atom or methyl, M ¹ is represented by a hydrogen atom, a monovalent metal, a divalent metal, ammonium, or an organic amine; [Formula 3]

In Chemical Formula 3, R ⁵ is a hydrogen atom or methyl, R ⁶ is alkylene, phenylene or alkylphenylene having 1 to 3 carbon atoms, R ⁷ is one kind or a mixture of two or more kinds of oxyalkylenes having 1 to 4 carbon atoms, and in the case of two or more kinds, R ⁷ may be added in a block or random phase, n is an integer of 10 to 50 as the average added mole number of the oxyalkylene group, M ² is a hydrogen atom, a monovalent metal, ammonium or an organic amine. The method of claim 6, The copolymerization method of the cement admixture, characterized in that carried out by a solution polymerization or bulk polymerization method. The method of claim 6, The copolymerization method of the cement admixture, characterized in that carried out at a reaction temperature of 0 to 120 ℃. The method of claim 6, The copolymerization method of the cement admixture, characterized in that carried out by further adding a thiol-based chain transfer agent. A cement composition comprising 0.01 to 10 parts by weight of the cement admixture according to claim 1 relative to 100 parts by weight of cement.