KR100219853B1 - Cement plasticizers - Google Patents

Abstract

The present invention relates to an antifoaming dispersant (or water reducing agent, a fluidizing agent) which can be used in combination with hydraulic cement.

Polycarboxylic acid-based copolymer dispersing agent has high dispersibility and good fluidity, so it has excellent slump holding power and excessive air entrainment when applied. Therefore, an antifoaming agent such as tributyl phosphate, water insoluble alcohol, silicone oil, etc. should be used separately. The added dispersants are not compatible with each other, so it is difficult to maintain the uniformity of the product when the antifoaming agent is separated into the upper layer within a short time due to the difference in specific gravity.

Accordingly, the present invention relates to polyoxypropylene alcohols, polyoxyethylene / polyoxypropylene copolymers or polyoxypropylene alkyl ethers having at least one terminal -OH group having a molecular weight of 1000-3500 in a dibasic acid anhydride such as maleic anhydride which can be polymerized with each other. By adding the ester compound added with acrylic acid or methacrylic acid and acrylic acid ester or methacrylic acid ester, it is possible to make a homogeneous aqueous solution without separating from each other, maintain high dispersibility, and have antifoaming properties. An integrated polycarboxylic acid-based copolymer dispersant which does not otherwise add or use an antifoaming agent.

Description

Antifoam Cement Dispersant

The present invention relates to a cement dispersant having excellent antifoaming properties in hydraulic cement. More specifically, the terminal group -OH group is added to an anhydrous dibasic acid anhydride such as acrylic acid or methacrylic acid and acrylic acid ester or a methacrylate anhydride polymerizable. To provide a cement dispersant of copolymers having excellent antifoaming properties by co-polymerizing an ester compound having at least two polyoxyfurophyllene alcohols, polyoxyethylene-polyoxyfuropyrene copolymers or polyoxyfuropyrene alkyl ethers. .

The present invention relates to a dispersant that has a fluidity and water-resistance function of mortar by blending with hydraulic cement. As a conventional cement sensitizer, ligrin sulfonic acid, polyol, gluconic acid, polycarboxylic acid, naphthalene sulfonic acid and melamine resin In order to complement the strengths and weaknesses of these water-sensitive dispersants, sulfonic acid systems are known. In particular, inexpensive and highly air-conducting lignin sulfonic acid, highly dispersible, low air ductility, low hydration delay, and excellent naphthalene sulfonic acid stability High-performance water-resistant dispersants in which a polycarboxylic acid system having high dispersibility and excellent slump holding power are mixed are commercialized.

Korean Patent Publication No. 86-1647 discloses 5-95% of alkali metal polyacrylates having an average molecular weight of 1,000-10,000 and alkali or alkaline earth metal naphthalenesulfonate-formaldehyde condensates and alkali or alkaline earth metal ligline sulfonates 90: A superplasmaizer sheet composition is disclosed which is formulated at a weight ratio of 10-10-10: 90. US Pat. No. 4473406 discloses a combination of acrylic or methacrylic acid with hydroxy alkyneacrylate or methacrylate. The use of tributylphosphate dibutyphthalate and various water-insoluble alcohols or silicone derivatives as an antifoaming agent is suggested as the polymer is represented as a high performance fluidizing agent and excessive air entrainment.

US Patent No. 5047087 is a copolymer composition of a high-performance fluidizing agent which is less expensive than Patent No. 4473406, and is characterized by being composed of acrylic acid, acrylic acid ester, and a third polymerizable henyl monomer. The use of appropriate antifoaming agents is recommended.

Korean Patent Publication No. 81-339 is characterized by improving the fluidity and the compressive strength of hydraulic cements by generating bubbles suitable for nonionic surfactants (especially polyoxyethylene / polyoxypropylene alcohol and polyol).

U.S. Patent No. 5087287 shows an increase in the strength of an unsaturated dicarboxylic acid such as maleic acid or fumaric acid and a hydrocurable cement added with an alkylene glycol or nonionic surfactant, and in U.S. Patent No. 4978392 polyoxyethylkenglycol and plymeric The polycarboxylates of fatty acids show improved fluidity and dispersibility. US Pat. No. 4,504,318 shows that lightweight and high-strength plastic concrete has polyalkylene glycols and vinyl monomers in which polyalkylene glycol is added to dibasic anhydride. It has been shown to be possible from emulsions of cement slurry.

U.S. Patent No. 4430463 discloses that the flexibility, abrasion, heat resistance, and shear bond properties are improved by using an acrylic polymer modified with phosphorus amount of propyleneglyol and using dimethyl polysiloxane as an antifoaming agent.

As mentioned above, the water soluble dispersant of the polycarboxylic acid-based copolymer shows high performance water soluble dispersibility and slump retention, but it is required to use an antifoaming agent by causing excessive air entrainment even at an appropriate amount (0.1-0.5%).

In addition, since the specific gravity of the general water soluble dispersant is generally 1.0 or more and is an aqueous solution, the antifoaming agent is usually 1.0 or less and does not dissolve in water. It is difficult to obtain powders, and it is complicated to add water-sensitive dispersant and antifoaming agent separately when cement slurry is mixed.

Excellent fluidity in the process of mixing mortar or slurry of conventional hydraulic cement

In order to prevent phase separation caused by the specific gravity difference between the dispersant and the antifoaming agent, a dispersant and the antifoaming agent are added. This is to solve all problems that occur in the process of mixing mortar or slurry.

The present invention solves the phase separation problem of the slurry caused by adding the dispersing agent and the antifoaming agent in the process of mixing the mortar or slurry of the conventional hydraulic cement, and further, to solve the problem of homogeneity of the cement hardened material (concrete) and to improve workability. Polycarboxylic acid-based water-disperse dispersant of mono-co-polymers having both vesicular and antifoaming functions. Such dispersants have a molecular weight of 1000-3500 in dibasic acid anhydrides such as acrylic acid or mepaacrylic acid and acrylic acid esters or methacrylic acid esters, and heavy acid maleic anhydride. Polycarpores having a molecular weight of 2000-50,000 obtained by copolymerizing ether compounds to which polyoxyfuropyrene alcohols having at least one terminal -OH group of N, polyoxyethylene-polyoxyfuropyrine copliers or polyoxyfuropyrene alkyl ethers are added Home-based copolymer dispersion Jay.

In more detail, the method for preparing a dispersant may be described in more detail: polyoxyfuropyrene alcohols having at least one terminal -H group having a molecular weight of 1000-3500 in a dibasic acid anhydride such as polymerizable maleic anhydride, and polyoxyethylene-polyoxyfuropyrenco Polymers or polyoxypropylene alkyl ethers were added and the reaction was carried out for 2 hours in the temperature range of 70-75 ° C., and the acid value was measured. Polyacrylic acid (AA) and mesyl acrylate (MA) were obtained. Addition of isopropyl alcohol as a solvent for polymerization to the ethyl acrylate (A) and the terta methyl acrylate (MMA), and the polymerization reaction with the aster compound by adding (2. 2 azobis isoyl tinonitrile) at a medium time. It is a polycarboxylic acid-based copolymer water soluble dispersant obtained by neutralizing with an alkali neutralizing agent.

As the alkali neutralizer used herein, caustic soda, alkali metals, alkaline metals, ammonia, and organic amines are used.

In the above, acrylic acid or methacrylic acid and acrylic acid ester or methacrylic acid ester are used together, and a small amount of ester compound is added thereto. The addition ratio is 60-90% of acrylic acid or methacrylic acid in weight ratio, and acrylic acid ester.

Or methacrylic acid ester is in the range of 5-40%, and the amount of the ester compound added is 0.1 or more and 10% or less. For this reason, when acrylic acid or metaacrylic acid is 50% or less, even if the obtained polymer is neutralized with an alkali neutralizing agent, it is difficult to dissolve in water and must dissolve at least 60% or more. On the other hand, when more than 10% of the aster compound is added, the weight reduction rate of the cured product is small, and the hydration reaction is significantly delayed, and the strength of cement is greatly decreased.

Polycarboxylic acid-based water dispersion system according to the present invention is a monolithic water-soluble dispersant that can maintain a uniform aqueous solution without phase separation at the time of mixing the slurry or mortar, and can control excessive air entrainment.

In order to clarify the above technical configuration and effect, the following examples are given.

Example 1.

The polymerizable maleic anhydride used in the present invention and polyoxypropylenealcones, polyoxyethylene / polyoxypropylene copolymers or polyxypropylenealkylethers having at least one terminal -OH group having a molecular weight of 1000-3500 are added. The obtained esterified product is polyoxypropylene alcohol, polyoxyethylene / polyoxypropylene copolymer or polyoxy having 10 g of maleic anhydride and at least one terminal-OH group having a molecular weight of 1000-3500 in a 500 m3 three-necked flask. Propylene alkyl ethers are added, the solution is heated to 70-75 ° C., ester addition reaction is performed for 2 hours, and the acid value is measured to obtain a sample of 95% or more.

Example 2

The polycarboxylic acid copolymer of Experiment NO.1 used in the present invention was placed in a 2000m1 four-necked flask with 900 g of isopropyl alcohol and 12 g of polyoxyethylene / polyoxypropylene alcohol or polyol maleate (A) of Table 1 as a polymerization solvent. When the temperature was raised to 50 ° C, 10 g of the polymerization catalyst 2,2 azont isobutylonitrile was added thereto, and the temperature was raised to 80 ° C within 20 minutes, and 288 g of acrylic acid and 100 g of methyl acrylate were continuously dropped for 2 hours. After 3 hours of aging, the solvent isopropyl alcohol is distilled off and recovered. When the amount of isopropyl alcohol reaches 50% of the input amount, 500 g of middle water is added and the isopropyl alcohol is recovered until the temperature reaches 100 ° C. Cold below 50 ℃

Continue to neutralize with 150 g of sodium hydroxide, adjust the solid content to 40% with midstream water, and leave the polymer catalyst decomposed product at room temperature for 1 day and filter it with a filter paper loaded with diatomaceous earth. About 1200 g of a composition of the anti-foaming dispersant having a mold viscosity of 25 ° C. and 50-1500 cps is obtained.

The experimental NO. Experiment NO.2 in 2 The polymerization method of up to 10 is the same as described above.

Experimental NO used in the present invention. Experiment NO. 1 in 1 The composition of the polycarboxylic acid copolymer up to 10 is shown in Table 2.

(AA: acrylic acid, MA: methyl acrylate, EA: ethyl acrylate, MMA: methacrylate)

Example 3.

A cement slurry was prepared on the basis of 0.4% (solid content / solid content) of the dispersant composition of the polycarboxylic acid copolymer shown in Table 2 by dissolving 2 parts of the dispersant composition as 70 parts of water, and 200 parts of cement (Hanil Cement Products). The mixture was pre-mixed and stirred for 3 minutes at 300 rpm with a stirring homogennai (Japanese model name DX-7), and the viscosity of the slurry was measured after 60 seconds with a Brookfield type B precision meter (Tokyo Co., Ltd.), and then again for 3 minutes at 3000 rpm. After stirring, the specific gravity of the slurry was measured with a 100cc specific gravity cup (SHEE INSTRIJMENT LTD., USA), and the air running ratio was obtained. Experiment NO. 1 in 1 In case of up to 5, NO. Experiment NO. From 6 Compared with up to 10, the viscosity of the slurry was lowered to 50-150 cps and the flowability was improved. The air running ratio was also reduced by 4-5%, thereby improving the excess air embrittlement of the polycarboxylic acid copolymer.

Example 4.

2 parts of the dispersant composition of the polycarboxylic acid copolymer shown in Table 2 was dissolved in 70 parts of water, and uniformly dissolved by adding 200 parts of cement (Hanil Cement), and stirred at 3000 rpm using a laboratory homogenizer (Japanese model name DX-7). After stirring for 3 minutes, 150 parts were taken in a 180cc paper cup, which was left at room temperature and cured. The weight loss and cement strength were measured over time, and the results are shown in Table 4 as a standard 100 for the experiment NO.9. NO. Experiment NO. 1 in 1 In case of up to 5, it showed good hydration reactivity and cement strength. In the case of 10% of the antifoaming component of 10, the weight loss rate and the weight loss amount after 28 days were too small, and the hydration reaction was excessively delayed and the strength of cement was also lowered.

No content.

Claims (2)

Polyoxypropylene alcohols having at least one terminal -OH group having a molecular weight of 1000-3500 in dibasic acid anhydrides such as 60-90% acrylic or methacrylic acid, 5-40% acrylic or methacrylic acid esters and maleic anhydride polymerizable by weight ratio A homogeneous aqueous solution obtained by copolymerizing 0.1-10% of an esterified product having a polyoxyethylene / polyoxypropylene copolymer or a polyoxypropylene alkyl ether, having a molecular weight of 2000-50000, a phosphorus copolymer, and neutralized with an alkali neutralizing agent. Anti-foaming polycarboxylic acid-based copolymer cement dispersant. (delete)