KR101617416B1 - Additive Including Polycarboxylic-based Copolymer and Cement Composition Comprising the Same - Google Patents

Abstract

The present invention relates to an additive for a cement composition comprising a polycarboxylic acid copolymer and a cement composition containing the same, and more particularly to a cement composition containing a polycarboxylic acid copolymer and / or a salt thereof, (Meth) acrylic acid ester monomer, a (meth) acrylic acid monomer and an alkylene oxide group having 5 to 20 carbon atoms and having at least two acrylate groups or vinyl groups And a water-soluble polycarboxylic acid-based copolymer are blended, and to a cement composition containing the same, wherein the polycarboxylic acid-based copolymer according to the present invention The additives of the cement composition can control the cross-linking structure, Improvement to be able to form the cement composition having excellent long time workability.

Description

[0001] The present invention relates to a cement composition containing a polycarboxylic acid-based copolymer and a cement composition containing the cement composition,

The present invention relates to an additive for a cement composition comprising a polycarboxylic acid copolymer and a cement composition containing the same.

A cement paste prepared by mixing cement, water and other additives, a mortar made by adding sand thereto, and a concrete prepared by additionally mixing gravel, which is a coarse aggregate, Are widely used in various construction materials and the like. However, after the cement composition is prepared, the cement composition begins to harden due to the hydration reaction between the cement and water over time, and the workability is getting worse. On the other hand, when the amount of water used is increased in order to improve the workability, the total amount of water used for the cement composition is limited because the compressive strength is lowered and cracks are generated. Thus, various cement additives have been developed to maintain the dispersibility of the cement composition while reducing the amount of water used.

Particularly, in the cement composition, the degradation of the slump occurred after 30 minutes in general, and all the work had to be completed in a short time from the concrete formulation to the pouring. In recent years, the cement additive which has higher water-reducing performance than the conventional water reducing agent due to the use of modernized mechanized equipment and traffic congestion, or has excellent slump retention performance, Has been required.

Various cement dispersants are currently used to improve the fluidity of the cement composition. However, in general, when a highly water-soluble hydraulic composition is prepared by using a cement dispersant, there is a problem that the slump loss is remarkable and workability and workability are deteriorated. Therefore, in order to prevent slump loss, conventionally, there has been an attempt to use a water-soluble polycarboxylic acid copolymer having a slump loss preventing property as a cement dispersant in itself. Examples of the water-soluble polycarboxylic acid copolymer include a water-soluble vinyl copolymer obtained by copolymerizing a methacrylate (Japanese Patent Laid-Open No. 1-226757, U.S. Patent No. 4,962,173, Japanese Patent Laid-open No. 4-209613), maleic anhydride and alkenyl ether And a derivative thereof (Japanese Patent Publication No. 58-38380, Japanese Patent Application Laid-open No. 63-285140, Japanese Patent Application Laid-open No. Hei 2-163108). However, in the conventional method using the water-soluble copolymer as a cement dispersant, there is a limit in that prevention of slump loss is insufficient.

Further, in order to prevent slump loss, proposals have been made to use a fluidity lowering agent in combination with a cement dispersant. As an example of such an example, a nonaqueous copolymer obtained from maleic anhydride and olefin is used in combination with a cement dispersant, and the property that the water-insoluble copolymer is hydrolyzed by the basic hydroxide generated by the hydration reaction of the cement and gradually becomes a water-soluble copolymer To obtain a slump loss preventing property (Japanese Patent Publication No. Hei 5-67579). However, in the conventional method of using the fluidity lowering agent as described above in combination with the cement dispersant, there is a disadvantage that the slump loss preventing effect is changed and deteriorated over time, and there is a disadvantage that the delay of the condensation is large.

On the other hand, Japanese Patent Application Laid-Open No. 7-267705 discloses a cement dispersant containing three kinds of polymers. Here, the first component is a copolymer (1) of a polyalkylene glycol mono (meth) acrylate compound and a (meth) acrylic acid compound, and the second component is a polyalkylene glycol mono (meth) (2), and the third component is a copolymer (3) of a polyalkylene glycol mono (meth) allyl ether compound and a maleic acid-esterified polyalkylene glycol compound. This document teaches that when component (1) is used alone it increases initial fluidity but is poor in slump retention and increases the viscosity of the cement composition. In addition, when the component (2) alone is used, time is required to increase the initial fluidity, and even if the initial fluidity is increased by increasing the amount of addition of the component (2), the phase separation of the cement composition . In addition, it is described that when component (3) is used alone, the dispersibility of the cement composition is further deteriorated. Therefore, it is described that an effect that can not be obtained by the sole use of each of the above three components is generated by using the above three components in combination at a specific ratio. The difference in the mechanism of action in the cement composition between the three components described in the document is due to the molecular weight of each component and the difference in the effect of increasing the initial flowability is that the (meth) acrylic acid-based functional group Containing polymer on the cement particles has a higher adsorption rate, resulting in a higher initial fluidity of the latter. Further, it is additionally described that the component having a higher adsorption rate results in poor ability to retain fluidity.

At present, the use of a combination of a polyalkylene glycol mono (meth) acrylate / (meth) acrylic acid copolymer and an unsaturated polyalkylene glycol monoalkenyl ether / maleic acid copolymer in a polycarboxylic acid copolymer Technology is known. However, currently, a cement composition having both sufficient initial dispersibility and slump retention has not yet been known, and it is necessary to add a large amount of dispersant for sufficient initial dispersibility. In particular, it is more difficult to select an additive capable of providing sufficient dispersibility and dispersibility in cement in a high water reducing rate range.

Therefore, there is a high need for a technology that can fundamentally solve these problems.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and the technical problems required from the past.

The inventors of the present application have conducted intensive research and various experiments and have found that it is possible to provide an initial dispersibility with excellent water reducing performance without addition of a water reducing agent or a slump preservative, A polycarboxylic acid copolymer capable of providing a slump retention force was developed and found to prevent the fluidity of the cement composition from being lowered when it was used as an additive for the cement composition, and thus the present invention has been accomplished.

It is another object of the present invention to provide a method for preventing the fluidity of a cement composition from deteriorating.

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

Accordingly, the additive of the cement composition according to the present invention includes a polycarboxylic acid copolymer and / or a salt thereof, and the polycarboxylic acid copolymer is an alkoxypolyalkylene glycol mono (meth) acrylate ester type A copolymer of a monomer mixture containing a monomer, a (meth) acrylic acid-based monomer and a cross-linking agent containing at least two acrylate groups or vinyl groups and having 5 to 20 alkylene oxide groups and a water-soluble polycarboxylic acid copolymer are blended .

The additive for a cement composition according to the present invention provides a dispersibility superior to that of a conventional cement additive and can improve the fluidity of the cement composition even in a region of high water reducing rate and can remarkably prevent deterioration of the obtained fluidity over a long period of time At the same time, a suitable amount of air can be continuously operated to impart good workability to the cement composition.

The polycarboxylic acid copolymer may be added as it is and used as a main component of the cement composition. If necessary, a copolymer salt obtained by neutralization with an alkaline substance may be further added to the cement composition.

In one specific example, the alkaline material may be at least one material selected from the group consisting of hydroxides, chlorides, carbonates, ammonia and organic amines of monovalent or divalent metals.

In one specific example, the polycarboxylic acid copolymer comprises 50 to 97.5% by weight of an alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer, 1 to 48.5% by weight of a (meth) acrylic acid monomer, And 0.1 to 10% by weight of a cross-linking agent containing an oxide group and having at least two acrylate groups or vinyl groups.

When the monomers are copolymerized in the above range, they are advantageous in exhibiting excellent dispersibility, slump retention and initial dispersibility, and have an excellent air entraining ability.

In one specific example, the alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer may be represented by the following formula (1).

(1)

(One)

In the above formula, R ¹ is a hydrogen atom or methyl, and R ² O is a mixed composition of one or more oxyalkylene having 2 to 4 carbon atoms. In the case of a mixture of two or more compounds, R ³ is alkyl having 1 to 4 carbon atoms, and m is an average addition mole number of oxyalkylene group is an integer of 50 to 200.

When the average addition mole number of the oxyalkylene group is 50 to 200, there is an effect of exhibiting excellent dispersibility and slump retention, and more specifically, it may be 50 to 150. [

The alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer represented by the above formula (1) is, for example, methoxypolyethylene glycol mono (meth) acrylate, methoxypolypropylene glycol mono (meth) acrylate, methoxypoly Butylene glycol mono (meth) acrylate, methoxypolyethylene glycol polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol polybutylene glycol mono (meth) acrylate, methoxypolypropylene glycol polybutylene glycol mono Ethoxypolyethylene glycol mono (meth) acrylate, methoxypolyethylene glycol polypropylene glycol polybutylene glycol mono (meth) acrylate, ethoxypolyethylene glycol mono (meth) acrylate, ethoxypolypropylene glycol mono (Meth) acrylate, ethoxypolyethylene glycol polypropylene glycol Mono (meth) acrylate, ethoxypolyethylene glycol polybutylene glycol mono (meth) acrylate, ethoxypolypropylene glycol polybutylene glycol mono (meth) acrylate and ethoxypolyethylene glycol polypropylene glycol polybutylene glycol mono (Meth) acrylate, and the like.

In one specific example, the (meth) acrylic acid-based monomer may be represented by the following general formula (2).

R ² -COOM ¹ (2)

Wherein R ² is a hydrocarbon group of 2 to 5 carbon atoms containing an unsaturated bond and M ¹ is a hydrogen atom, a monovalent or divalent metal, an ammonium group or an organic amine salt.

The (meth) acrylic acid-based monomer represented by the above-mentioned general formula (2) may be, for example, at least one monomer 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 Lt; / RTI >

The crosslinking agent is not particularly limited as long as it contains 5 to 20 alkylene oxide groups and has 2 or more acrylate groups or vinyl groups. Such crosslinking agents include, for example, polyethylene glycol diacrylate (PEGDA), polypropylene glycol diacrylate (PPGDA), 1,6-hexanediol ethoxylate diacrylate, 1,6-hexanediol propoxylate diacrylate, neopentyl glycol ethoxylate diacrylate, neopentyl glycol propoxylate (diacrylate), neopentyl glycol propoxylate diacrylate diacrylate, trimethyl propane ethoxylate triacrylate, trimethyl propane propoxylate triacrylate, pentaerythritol ethoxylate triacrylate, or pentaerythritol ethoxylate triacrylate. Lithol propoxylate triacrylate It may be (Pentaerythritol propoxylate triacrylate) at least one monomer selected from the group consisting of mixed to be used.

As the proportion of the polycarboxylic acid copolymer copolymerized further including the cross-linking agent increases, the polyalkylene glycol chain induces hydrophilicity and inter-particle dispersion due to steric repulsion, so that the initial sensitivity and retention To thereby provide excellent workability for a long period of time.

Since the alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer has a double bond capable of participating in a radical reaction, it can copolymerize with the monomers to induce electrostatic repulsion and stability between the dispersed particles, The slump fluidity is maintained to minimize the change over time of the cement composition.

The polycarboxylic acid copolymer may be prepared by copolymerizing the monomer components using a polymerization initiator, and the copolymerization method may be carried out by solution polymerization or bulk polymerization, but is not particularly limited thereto.

For example, when water is used as a solvent, a solution polymerization initiator to be used may be a water-soluble polymerization initiator such as persulfate of ammonium or alkali metal or hydrogen peroxide, and may be a lower alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, Or polymerization using a ketone compound as a solvent, an aromatic azo compound such as benzoyl peroxide or hydroperoxide such as lauroyl peroxide cumene hydroperoxide or azobisisobutyronitrile may be used as a polymerization initiator. At this time, an accelerator such as an amine compound may be used in combination. When a water-lower alcohol mixed solvent is used, it may be appropriately selected from the above-mentioned various polymerization initiators or a combination of a polymerization initiator and an accelerator.

The amount of the appropriate polymerization initiator to be used may be in the range of 0.5 to 5% by weight based on the total weight of the monomer mixture, and the polymerization temperature may be in the range of 0 to 120 占 폚 You can choose from a range.

In order to control the molecular weight of the obtained polycarboxylic acid copolymer, a thiol chain transfer agent may be used together. The thiol-based chain transfer agent used herein is selected from the group consisting of mercaptoethanol, thioglycerol, thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, thiofaconic acid, octyl thioglycolate and octyl 3-mercaptopropionate ≪ / RTI > The amount of the thiol chain transfer agent used may be, in particular, from 0.01 to 5% by weight based on the total weight of the monomer mixture.

In one specific example, the polycarboxylic acid copolymer and the copolymer salt in which the polycarboxylic acid copolymer is neutralized, when measured by GPC (Gel Permeation Chromatography), is in the range of 30,000 to 70,000 And more specifically, from 40,000 to 60,000.

The present invention also relates to a process for producing an acrylic resin composition comprising an alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer, a (meth) acrylic acid monomer and a crosslinking agent containing 5 to 20 alkylene oxide groups and having at least two acrylate groups or vinyl groups At least one member selected from the group consisting of a polycarboxylic acid copolymer which is a copolymer of a monomer mixture and / or a copolymer salt which is obtained by neutralizing the polycarboxylic acid copolymer with an alkaline substance; And a water-soluble polycarboxylic acid copolymer product; and an additive blended with the cement composition.

In one specific example, the additive of the cement composition may be included in an amount of 0.01 to 10 parts by weight, more specifically 0.05 to 5 parts by weight, and more specifically 0.1 to 5 parts by weight based on 100 parts by weight of the cement. It is advantageous that the additive of the cement composition is included in the above range to provide excellent flowability even in the region of high yield. If the amount is less than 0.05 parts by weight, particularly less than 0.01 parts by weight, it is difficult to exhibit desired performance such as slump retention, water reduction and air entrainment.

The cement composition is known in the art including cement paste prepared by adding water to cement, mortar prepared by adding sand as fine aggregate thereto, and concrete produced by additionally mixing gravel as a coarse aggregate thereon Gt; cement < / RTI >

The present invention also relates to a method for preventing the deterioration of the fluidity of the cement composition, which comprises a step of containing an alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer, a (meth) acrylic acid monomer and 5 to 20 alkylene oxide groups, Or more of a monomer mixture containing a crosslinking agent having an acrylate group or a vinyl group and / or a copolymer salt obtained by neutralizing the polycarboxylic acid copolymer with an alkaline substance Species; And a water-soluble polycarboxylic acid copolymer product; and a method of preventing a decrease in fluidity of a cement composition in which air is continuously passed through the cement composition.

In this connection, the appropriate amount of air to be continuously circulated is not particularly limited, but may be 1 to 9%, and more particularly, 3 to 5% in the case of unhardened concrete.

As described above, according to the present invention, it is possible to provide an acrylic resin composition containing an alkoxypolyalkylene glycol mono (meth) acrylate ester monomer, a (meth) acrylic acid monomer and 5 to 20 alkylene oxide groups, By using an additive blended with a polycarboxylic acid-based copolymer polymerized with a vinyl group-containing cross-linking agent and a water-soluble polycarboxylic acid-based copolymer, the fluidity of the composition can be improved even in a region of high water- It is possible to have an excellent effect in prevention.

In addition, the present invention has an effect that very good workability can be imparted to the cement composition by continuously operating an appropriate amount of air in the cement composition.

Hereinafter, the present invention will be described with reference to Examples. However, the following Examples are intended to illustrate the present invention, and the scope of the present invention is not limited thereto.

≪ Example 1 >

150 parts by weight of water was poured into a glass reactor having a capacity of 2 L equipped with a thermometer, a stirrer, a dropping funnel, a nitrogen inlet tube and a reflux condenser, and the inside of the reaction vessel was replaced with nitrogen under stirring and heated to 80 DEG C under a nitrogen atmosphere.

After 20 parts by weight of an aqueous ammonium persulfate solution having a concentration of 3% by weight was added to the reactor, 300 parts by weight of methoxypolyethylene glycol monomethacrylate (average molar number of added ethylene oxide: 50 moles) as a polymerization composition, 35 parts by weight of acrylic acid , 0.25 part by weight of polyethylene glycol diacrylate (average molar number of addition of ethylene oxide: 5 moles) as a crosslinking agent, and 50 parts by weight of water, 2.5 parts by weight of 2-mercaptoethanol and 30 parts by weight of water, % Aqueous ammonium persulfate solution was added dropwise over 4 hours. After completion of the dropwise addition, 10 parts by weight of an aqueous ammonium persulfate solution having a concentration of 3% by weight was added thereto at a time. Thereafter, the temperature was maintained at 80 캜 for one hour to complete the polymerization reaction.

After the polymerization was completed, the mixture was cooled to room temperature, and neutralized with a 30% by weight aqueous solution of sodium hydroxide for about 1 hour to obtain a solid content of 50%. The salt of the water-soluble copolymer prepared as described above had a weight average molecular weight of 44,000 as determined by gel permeation chromatography (GPC).

The water-soluble polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (manufactured by LIG Chemical Co., Ltd., trade name CP-WRM50) prepared above were blended in a ratio of 3: 7.

≪ Example 2 >

The water-soluble polycarboxylic acid copolymer produced in Example 1 and the water-soluble polycarboxylic acid copolymer (manufactured by LL Chemical Co., Ltd., trade name CP-WRM50) were blended in a ratio of 5: 5.

≪ Example 3 >

The water-soluble polycarboxylic acid copolymer produced in Example 1 and the water-soluble polycarboxylic acid copolymer (product name: CP-WRM50) were blended in a ratio of 7: 3.

<Example 4>

Except that a monomer aqueous solution obtained by mixing 0.25 part by weight of polyethylene glycol diacrylate (average molar number of addition of ethylene oxide: 10 mol) as a crosslinking agent in the polymerization composition in Example 1 was used, and The salt of the water-soluble copolymer thus prepared had a weight average molecular weight of 43,000 as determined by gel permeation chromatography (GPC).

The water-soluble polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (manufactured by LIG Chemical Co., Ltd., trade name CP-WRM50) prepared above were blended in a ratio of 3: 7.

&Lt; Example 5 >

The water-soluble polycarboxylic acid copolymer prepared in Example 4 and the water-soluble polycarboxylic acid copolymer (manufactured by LIG Chemical Co., Ltd., trade name CP-WRM50) were blended in a ratio of 5: 5.

&Lt; Example 6 >

The water-soluble polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (manufactured by LG Chemical Co., Ltd., trade name CP-WRM50) prepared in Example 4 were blended in a ratio of 7: 3.

&Lt; Example 7 >

Except that a monomer aqueous solution obtained by mixing 0.25 part by weight of polyethylene glycol diacrylate (average molar number of addition of ethylene oxide: 20 mol) as a crosslinking agent in the polymerization composition in Example 1 was used, and The salt of the water-soluble copolymer thus prepared had a weight average molecular weight of 44,000 as measured by Gel Permeation Chromatography (GPC).

The water-soluble polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (manufactured by LIG Chemical Co., Ltd., trade name CP-WRM50) prepared above were blended in a ratio of 3: 7.

&Lt; Example 8 >

The water-soluble polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (manufactured by LG Chemical Co., Ltd., trade name CP-WRM50) prepared in Example 7 were blended in a ratio of 5: 5.

&Lt; Example 9 >

The water-soluble polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (manufactured by LG Chemical Co., Ltd., trade name CP-WRM50) prepared in Example 7 were blended in a ratio of 7: 3.

&Lt; Comparative Example 1 &

The same procedure as in Example 1 was carried out except that a monomer aqueous solution not containing a crosslinking agent was used in the polymerization composition of Example 1. The salt of the water soluble copolymer thus prepared was subjected to Gel Permeation Chromatography (GPC) And the weight average molecular weight measured by the method was 44,000.

The water-soluble polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (manufactured by LIG Chemical Co., Ltd., trade name CP-WRM50) prepared above were blended in a ratio of 3: 7.

&Lt; Comparative Example 2 &

The water-soluble polycarboxylic acid copolymer prepared in Comparative Example 1 and the water-soluble polycarboxylic acid copolymer (product name: CP-WRM50, manufactured by LIG Corporation) were blended in a ratio of 5: 5.

&Lt; Comparative Example 3 &

The water-soluble polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (manufactured by LG Chemical Co., Ltd., trade name CP-WRM50) prepared in Comparative Example 1 were blended in a ratio of 7: 3.

&Lt; Comparative Example 4 &

Except for using a monomer aqueous solution obtained by mixing 0.25 part by weight of diethylene glycol diacrylate (average molar number of addition of ethylene oxide: 2 mol) as a crosslinking agent in the polymerization composition in Example 1, and The salt of the water-soluble copolymer thus prepared had a weight average molecular weight of 43,000 as determined by gel permeation chromatography (GPC).

The water-soluble polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (manufactured by LIG Chemical Co., Ltd., trade name CP-WRM50) prepared above were blended in a ratio of 3: 7.

&Lt; Comparative Example 5 &

The water-soluble polycarboxylic acid copolymer prepared in Comparative Example 4 and a water-soluble polycarboxylic acid copolymer (product of LIG Chemical Co., Ltd., trade name CP-WRM50) were blended in a ratio of 5: 5.

&Lt; Comparative Example 6 >

The water-soluble polycarboxylic acid copolymer produced in Comparative Example 5 and the water-soluble polycarboxylic acid copolymer (product name: CP-WRM50) were blended in a ratio of 7: 3.

The types and contents of the crosslinking agent and the weight average molecular weight of the water-soluble polycarboxylic acid copolymer salt prepared in Examples 1 to 9 and Comparative Examples 1 to 6 are shown in Table 1 below.

division Cross-linking agent Weight average molecular weight Kinds Content (parts by weight) Ethylene oxide number Example 1 PEGDA 0.25 5 44,000 Example 4 PEGDA 0.25 10 43,000 Example 7 PEGDA 0.25 20 44,000 Comparative Example 1 - - - 44,000 Comparative Example 4 DEGDA 0.25 2 43,000

<Experimental Example 1>

Mortar flow test

500 g of ordinary portland cement (manufactured by Ssangyong Cement Co., Ltd.), 800 g of sand, 1.0 g of each polycarboxylic acid copolymer (in terms of solid content) and 180 g of water (water) were kneaded in an mortar mixer for 3 minutes to prepare a mortar . Each prepared mortar was filled into a hollow cone having a diameter of 60 mm and a height of 40 mm, and then the cone was lifted in a vertical direction. The mortar flow value (mm) was determined by measuring the mortar diameter in both directions and the average of the measured diameters.

<Experimental Example 2>

Concrete test

680 kg of ordinary Portland cement (manufactured by Ssangyong Cement Co., Ltd.), 1700 kg of sand, 1850 kg of crushed stone, and 0.23% by weight of cement weight and 370 kg of water (water) were mixed with each polycarboxylic acid copolymer to prepare concrete. The slump and air content of each concrete were measured by KS F 2402 and KS F 2449.

The results of Experimental Examples 1 and 2, in which the salts of these water soluble copolymers were compounded and applied to cement concrete, are shown in Table 2 below.

division Additive amount / cement
(weight%) mortar
Flow value (mm) Slump (cm) Air volume (%) Early 60 minutes Early 90 minutes Early 90 minutes Example 1 0.2 140 150 20.5 21.5 4 4 Example 2 0.2 142 153 21 22.5 4 4 Example 3 0.2 139 149 20.5 22 4 4 Example 4 0.2 143 152 21 22.5 4 3.5 Example 5 0.2 145 155 21.5 23 3.5 3.5 Example 6 0.2 144 153 21 22.5 4 4 Example 7 0.2 142 152 21 22 4 4 Example 8 0.2 143 153 21 22.5 4 3.5 Example 9 0.2 141 151 21 22 4 4 Comparative Example 1 0.2 133 139 19.5 20 4.5 4.5 Comparative Example 2 0.2 135 143 20 20.5 4.5 4.5 Comparative Example 3 0.2 134 141 20 20 4.5 4.5 Comparative Example 4 0.2 135 141 20 20.5 4.5 4.0 Comparative Example 5 0.2 137 142 20.5 20.5 4.5 4.0 Comparative Example 6 0.2 135 140 20 20 4.5 4.5

As shown in Table 2, the results of the mortar applied by blending the water-soluble polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (LG Chemical Co., Ltd., trade name CP-WRM50) in Examples 1 to 9, Compared with the mortar applied by blending the polycarboxylic acid copolymer and the water-soluble polycarboxylic acid copolymer (product of LIG Chemical Co., Ltd., CP-WRM50) applied with a crosslinking agent having a small number of ethylene oxides except for the crosslinking agent in Examples 1 to 6 , The initial dispersibility and the mortar flow value after 60 minutes showed a relatively high fluid retentivity. In the concrete application experiment, not only the slump value after 90 minutes was relatively high but also the air quantity was excellent. That is, when the water-soluble polycarboxylic acid copolymer and the product of the present invention (manufactured by LG Chemical Co., Ltd., trade name CP-WRM50) are blended and applied, the dispersibility of the cement particles is further improved. Indicating that the fluidity retention force is exhibited.

Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims (14)

In the additive for a cement composition comprising a polycarboxylic acid copolymer and / or a salt thereof,
Wherein the polycarboxylic acid copolymer comprises 50 to 97.5% by weight of an alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer, 1 to 48.5% by weight of a (meth) acrylic acid monomer, And 0.1 to 10% by weight of a crosslinking agent containing at least two alkylene oxide groups and having at least two acrylate groups or vinyl groups,
Wherein the water-soluble polycarboxylic acid-based copolymer is blended. The additive for cement composition according to claim 1, wherein the blend ratio of the polycarboxylic acid-based copolymer to the water-soluble polycarboxylic acid copolymer is 2: 8 to 8: 2 by weight. The additive for a cement composition according to claim 1, wherein the salt of the polycarboxylic acid copolymer is a copolymer salt prepared by neutralizing the polycarboxylic acid copolymer obtained by adding an alkaline substance to the polycarboxylic acid copolymer. delete The cement composition according to claim 1, wherein the alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer is represented by the following Formula 1:

(One)
In this formula,
R ¹ is a hydrogen atom or methyl;
R ² O is a mixed composition of one or more oxyalkylene having 2 to 4 carbon atoms;
R ³ is alkyl having 1 to 4 carbon atoms;
m is an average addition mole number of the oxyalkylene group and is an integer of 50 to 200; The method of claim 5, wherein R ² O is an additive for cement compositions, characterized in that the composition consists of a mixture of two or more kinds of oxyalkylene group having 2 to 4 carbon atoms included in blocks or randomly. The method of claim 5, wherein the alkoxypolyalkylene glycol mono (meth) acrylic acid ester monomer represented by Formula 1 is at least one selected from the group consisting of methoxypolyethylene glycol mono (meth) acrylate, methoxypolypropylene glycol mono (meth) Methoxypolyethylene glycol mono (meth) acrylate, methoxypolyethylene glycol polypropylene glycol mono (meth) acrylate, methoxypolyethylene glycol polybutylene glycol mono (meth) acrylate, methoxypolypropylene glycol polybutylene glycol (Meth) acrylate, ethoxypolyethylene glycol mono (meth) acrylate, methoxypolyethylene glycol polypropylene glycol polybutylene glycol mono (meth) acrylate, ethoxypolyethylene glycol mono Polybutylene glycol mono (meth) acrylate, ethoxypolyethylene glycol polypropyl (Meth) acrylate, ethoxypolyethylene glycol polybutylene glycol mono (meth) acrylate, ethoxypolypropylene glycol polybutylene glycol mono (meth) acrylate, ethoxypolyethylene glycol polypropylene glycol polybutylene glycol Mono (meth) acrylate, and mixtures thereof. The additive of the cement composition according to claim 1, wherein the at least one monomer is a mono (meth) acrylate. The cement composition according to claim 1, wherein the (meth) acrylic acid monomer is represented by the following formula (2):
R ² -COOM ¹ (2)
In this formula,
R ² is a hydrocarbon group of 2 to 5 carbon atoms containing an unsaturated bond;
M ¹ is a hydrogen atom, a monovalent or divalent metal, an ammonium group or an organic amine salt. (Meth) acrylic acid-based monomer represented by the formula (2) is at least one selected from the group consisting of acrylic acid, methacrylic acid, monovalent metal salts thereof, divalent metal salts, ammonium salts and organic amine salts Wherein the additive is a monomer. The crosslinking agent according to claim 1, wherein the crosslinking agent having 5 to 20 alkylene oxide groups and having 2 or more acrylate groups or vinyl groups is selected from the group consisting of polyethylene glycol diacrylate (PEGDA), polypropylene glycol diacrylate propylene glycol diacrylate, PPGDA, 1,6-hexanediol ethoxylate diacrylate, 1,6-hexanediol propoxylate diacrylate, neopentyl glycol ethoxylate diacrylate, Acrylate, neopentyl glycol ethoxylate diacrylate, neopentyl glycol propoxylate diacrylate, trimethyl propane ethoxylate triacrylate, trimethylpropanepropoxylate triacrylate (Trimethy propane propoxylate triacrylate), pentaerythritol ethoxylate triacrylate Sites (Pentaerythritol ethoxylate triacrylate) or pentaerythritol propoxy triacrylate (Pentaerythritol propoxylate triacrylate) additives of the cement composition, characterized in that at least one monomer selected from the group consisting of. The additive of claim 1, wherein the additive of the cement composition has a weight average molecular weight of 30,000 to 70,000. (Meth) acrylic acid monomer based on the total weight of the copolymer and 50 to 97.5% by weight of an alkoxypolyalkylene glycol mono (meth) acrylate monomer, 1 to 48.5% by weight of a (meth) And 0.1 to 10% by weight of a cross-linking agent having at least one acrylate group or a vinyl group, and / or a copolymer salt obtained by neutralizing the polycarboxylic acid-based copolymer with an alkaline substance At least one selected from the group consisting of: And
Soluble polycarboxylic acid copolymer product;
&Lt; / RTI &gt; by weight of the cement composition. 13. The cement composition according to claim 12, wherein the additive is included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the cement. As a method for preventing the fluidity of the cement composition from deteriorating,
(Meth) acrylic acid monomer based on the total weight of the copolymer and 50 to 97.5% by weight of an alkoxypolyalkylene glycol mono (meth) acrylate monomer, 1 to 48.5% by weight of a (meth) And 0.1 to 10% by weight of a cross-linking agent having at least one acrylate group or a vinyl group, and / or a copolymer salt obtained by neutralizing the polycarboxylic acid-based copolymer with an alkaline substance , An additive blended with a water-soluble polycarboxylic acid copolymer product, and a cement composition comprising the cement composition, wherein air is continuously passed through the cement composition Of the flowability of the fluid.