KR100912033B1 - Cement aid for early strength-enhanced - Google Patents

Abstract

A cement additive is provided to secure early strength and to improve grinding efficiency, quality and productivity by being used as a grinding aid and to ensure excellent compatibility with an admixture. A cement additive for improving early compressive strength comprises any one or a mixture of at least two selected from N,N-bis-(2-hydroxypropyl)-(hydroxymethoxymethyl)amine of chemical formula II, N,N-bis-(2-hydroxypropyl)-(hydroxymethoxyethyl)amine of chemical formula III, and N-(hydroxymethoxymethyl)-N-(hydroxyethyl)-N-(2-hydroxypropyl)amine of chemical formula IV. The additive is included in the amount of 0.0005~5 parts by weight as a grinding aid based on the cement clinker 100.0 parts by weight.

Description

Cement aid for early strength-enhanced

The present invention relates to a functional cement additive having the characteristics of early compressive strength and hydration promotion during cement casting. More specifically, the present invention relates to a cement additive that can be used as an admixture for imparting early compressive strength or increasing the production efficiency per unit time and reducing energy costs by adding an additive in the process of crushing the clinker.

Clinker is produced by firing at 1300 ℃ or more in cement production process, and the clinker is crushed into ball mill and roller mill by wet and dry method.

In addition, cement is useful in various forms as a binder or an adhesive in the construction and civil engineering fields. Particularly known cements are first class Portland cements, which are widely used in most construction and civil engineering applications. When the one kind of Portland cement is mixed with water as a hydraulic cement, it forms a dough and gradually solidifies and hardens with time. These cements are further mixed with sand to form mortar, and mixed with sand (grain aggregate), coarse aggregate, and water to produce concrete. The products of these cements depend on the quality and properties of hydraulic cement.

This portland cement is produced by milling the clinker. Clinker is prepared by calcining a mixture of components comprising calcium carbonate, aluminum oxide, silicon dioxide, and mixed iron oxide. Chemical reactions occur during the firing process to form hardened nodules, commonly referred to as clinkers. After the clinker is cooled, it is ground with a small amount of gypsum (CaSO ₄ ) or slag in the finishing mill to obtain a uniform powdery product known as Portland cement.

Past grinding aids are mostly unsaturated fatty acids with low polymerization degree, amines, alcohols, and amides such as diethyleneglycol (DEG), glycol alkanolamines, and amine acetates. As described above, they improved the grinding capacity (output per unit time) and physically adsorbed to the cement particles, thereby improving the strength and physical properties of the cement.

U.S. Patent No. 4,943,323 discloses a method of partially mixing triethanolamine (TEA) with triisopropanolamine (TIPA) and using it as a grinding aid. U.S. Patent No. 6,290,772 discloses a method of mixing triisopropanolamine (TIPA) with diisopropanolethanolamine (EDIPA) and isopropanoldiethanolamine (DEIPA) and using them as grinding aids. Korean Patent Registration No. 10-0596507, Japanese Patent Application Laid-open No. Hei 10-324550 discloses a method of using a compound substituted with acetic acid or a carboxyl group having 2 to 4 carbon atoms, sulfate or ester group in TEA and TIPA as an additive for grinding aid. . Korean Patent No. 10-0650135 discloses a method of mixing glycol and alkanolamine in polypropylene ethanolamine and performing the additive as a grinding aid. In this patent, the grinding aid additive is added in an amount of 0.002 to 0.2wt% based on the weight of the clinker to improve the physical property change of the strength of Portland cement. The alkanolamine compound prevents the ferric hydroxide produced during hydration from being precipitated into the gel at high pH when it is added as a grinding aid additive to form a complex with iron and undergoes the hydration reaction of iron aluminate. Induce to improve the strength of cement. Until now, the additives used as the grinding aids described above have been explained on the basis of the mechanism importance due to the binding relationship between iron and amine and on the hydrophilic / lipophilic (HLB) theory.

However, although the improvement of the grinding efficiency and productivity of the clinker has been improved to some extent, there is a continuing demand for a grinding aid having an early compressive strength function.

The present invention seeks to provide a cement additive that improves premature compression strength as well as dispersibility in order to meet the needs as described above.

Specifically, it is used for grinding cement clinker to improve grinding efficiency, quality and productivity, and to be used as a grinding aid to improve premature compression strength and hydration promotion, or as a compounding agent having early compression strength and hydration promotion when added to cement composition. It is intended to provide a cement additive that can be used.

More specifically, the hydrophilicity is improved in the derivative of the amine compound used as the grinding aid in the grinding process of Portland cement, and furthermore, the clinker particles and the grinding aid are utilized by utilizing steric hindrance due to the compactness of the functional and molecular structures, and electrical properties. Adsorption between particles and mutual electrical repulsion effect between particles to improve dispersibility, increase grinding efficiency, and meet high strength based on amine compound to improve cement quality and production competitiveness with energy saving and cost reduction It is to provide a cement additive exhibiting compressive strength.

The present invention relates to a cement additive for improving early compressive strength, and to a cement additive used as a grinding aid or admixture.

More specifically, the present invention provides N, N-bis- (2-hydroxypropyl)-(hydroxymethyl) amine of formula 1, and N, N-bis- (2-hydroxypropyl)-(hydride of formula 2) Hydroxymethoxymethyl) amine, N, N-bis- (2-hydroxypropyl)-(hydroxymethoxyethyl) amine of formula (3), N- (hydroxymethoxymethyl) -N- of formula (4) It relates to a cement additive consisting of any one or a mixture of two or more selected from (hydroxyethyl) -N- (2-hydroxypropyl) amine.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

Conventional amine compounds, alcohols, fatty acids and the like have excellent grinding efficiency but poor early compressive strength development. Therefore, the present invention, in addition to the hydrophilic and lipophilic theory (HLB) previously mentioned in the grinding efficiency, to increase the electrostatic repulsive force due to steric hindrance to improve the dispersibility and satisfy the grinding efficiency and early compression strength expression, hydration promoting function Developed a cement additive.

The conventionally developed technology is limited to triethanolamine (TEA), triisopropylamine (TIPA) and derivatives synthesized with two to four carbon alcohols or esters in the preceding two compounds. In the present invention, while studying a cement additive having superior early compressive strength, the present invention has a -OH functional group and a methyl functional group at the same time, and shows a premature compressive strength when both a single isopropyl group and an ethanol group and a methanol and isopropanol group are present in TIPA and TEA. The present invention has been completed by discovering that it can be provided.

Moreover, when the hydroxymethyl group in the compound of Formula 1 is surprisingly compared with other hydroxyalkyl, for example, hydroxyethyl, hydroxypropyl, the curing time is very fast and has a relatively very strong effect of increasing the cement composition I found it very effective as a component of.

The cement additive exhibiting early compressive strength according to the present invention has a -OH functional group and a methyl functional group at the same time, compared to the conventional (tri, di, mono) isopropanolamine and (tri, di, mono) ethanolamine. -OH functional group, which acts to adsorb clinker particles like conventional triisopropanolamine, and methyl group having steric hindrance and electrical repulsion force to disperse the dispersed particles to prevent condensation and lubrication It reduces the grinding time per unit time and makes it possible to grind evenly the particle size. When the isopropanol and methanol group are attached to the isopropanol group and the ethanol group instead of the amine, the early compression strength is improved. The composition used as a grinding aid is coated on the surface of the particles of the finely ground clinker, so that the dispersibility is improved when used for cement, and the basic strength is increased by water absorption to act as a admixture. The above compound itself can show early compressive strength and can be used as a admixture.

That is, in the present invention, the compound is used as a admixture as a single substance or as a mixture, or used as a grinding aid to be added to the clinker grinding process, and used alone or in combination with other additives to obtain the early compressive strength. I can regulate it. Exemplary additives used in combination include glycol-based additives for increasing grinding efficiency.

In the present invention, the cement additive is preferably added in an amount of 0.0005 to 5 parts by weight based on 100 parts by weight of the clinker when used as a grinding aid during the grinding of the cement clinker. If the amount is less than 0.0005 parts by weight, the effect is insignificant, and if it is more than 5 parts by weight, it is not preferable because the flocculation and entanglement occurs in the cement manufacturing process, thereby improving the efficiency of the pulverization.

In addition, the cement additive of the present invention is preferably used in the range of 1 to 50% by weight of the total admixture content when used as a admixture. If the amount is less than 1% by weight, the effect is insignificant, and when the amount is more than 50% by weight, strength and physical properties are deteriorated.

In addition, if the additive is commonly used in the art is not limited and may be used by adding more. For example, water-reducing agents such as lignin, naphthalene, melamine, glycols such as DEG (diethylene glycol), and TEA (triethanolamine) may be further added.

The present invention relates to a cement additive that realizes basic grinding efficiency and early compressive strength, and can be used as a clinker grinding aid or admixture.

The grinding aid according to the present invention has a grinding efficiency using the principle of adsorption and repulsion by hydrophilicity and steric repulsion while maintaining the existing -OH functional group.

In particular, as shown in the results of the Example, the early compression strength was the best when the amine has an ester group including isopropyl group and ethanol, methanol group at the same time. It is remarkably superior in terms of early compressive strength compared to existing grinding aids, thus securing economic feasibility in shortening construction period and realizing high strength. The method can also be used freely for pulverization or admixtures, and is expected to help a lot in the construction of special-purpose buildings such as ports, dams, airports, and high-rise buildings.

Hereinafter, the present invention will be described by way of example for specific description of the present invention, but the present invention is not limited to the following examples.

[Examples 1 to 4 and Comparative Examples 1 to 2]

When used as a grinding aid

In the present invention, the same amount of grinding was added to the same clinker in Table 1, and the experiment was conducted to compare the particle size and the grinding efficiency.

Table 2 shows the powder and residues according to the compound for the grinding aid. To 2 kg of cement clinker, the compounds of the following Chemical Formulas 1 to 4 were mixed as 0.02 parts by weight (40 g), respectively, and water was diluted by 5 times (200 g) compared to the grinding aid to grind for 30 minutes. The mill used a drum mill with a drum size Φ 500 * 600 mm and a rotation speed of 40 rpm.

Powder degree was performed by the KS L 5106 method, and the residue was measured using a 44 μm sieve.

[Formula 1]

[Formula 2]

[Formula 3]

[Formula 4]

Table 1. Cement Clinker Ingredients

Table 2. Powder diagram for grinding aid

As shown in Table 2, it can be seen that the powder level is 3224 to 3281, the residue amount is 11% or less, especially when the compound of Formula 2, Formula 3, Formula 4 is added, the powder is high, the residue is low Could know.

On the other hand, the conventionally used triisopropylamine had a high powder degree but a high residual amount, and when the grinding aid was not added as in Comparative Example 2, the powder was also low and the residue was very high. In general, when the residual amount is high, the efficiency of the pulverized continuous pulverization production using a classifier is shown.

[Examples 5 to 8 and Comparative Examples 3 to 4]

Using the finely ground cement prepared in Example 1 was mixed with aggregate to measure the condensation and mortar compressive strength at intervals of 1, 3, 7, 28 days. The test specimen for strength test of concrete for measuring the compressive strength was made according to KS F 2403, and the compressive strength was measured according to KS F 2405. The water / cement ratio was 0.485, and the compressive strength was measured every 1, 3, 7, 28 days using a mold of 5 × 5 × 5 cm 3.

Table 3. Mortar compressive strength when cement additive is used as grinding aid

As shown in Table 3, the compressive strength was shown to be excellent in the formula (2), formula (3), and formula (4), as shown in Example 1 was also affected by the strength of the powder and residue. This resulted in the presence of polar functional groups in the form of a mixture of isopropanol, methanol and ethanol ester groups in tertiary amines, thereby improving grinding efficiency, improving dispersibility by electrostatic interaction, and improving mortar compressive strength in the final stage. It is judged to indicate.

[Examples 9 to 12 and Comparative Example 5]

When used as a cement admixture

Cement used 760 g of Portland cement of Sungshin Yang company, 1,862 g Jumunjin standard yarn (for compressive strength, KSL 5100) was used as standard yarn, and 10 wt% of the compounds of Formulas 1 to 4 were used as admixtures. And 90% by weight of lignin was mixed and used. The content of admixture was used at 0.05% by weight relative to the cement content. Water was added thereto so that the water / cement ratio was 0.485, followed by mixing to make a mold of mortar 5 × 5 × 5 cm 3. The compressive strength was measured every 1, 3, 7, and 28 days.

Table 4. Compressive strength when cement additive is used as admixture

As shown in Table 4, even when used as a admixture, when compared to the case of not adding the additive of the present invention, compared with the compressive strength for 1 to 7 days it was confirmed that 10% or more higher than the strength and the early compression strength is expressed.

Claims (6)

N, N-bis- (2-hydroxypropyl)-(hydroxymethoxymethyl) amine of formula (2), N, N-bis- (2-hydroxypropyl)-(hydroxymethoxy) of formula (3) Early compression strength consisting of any one or a mixture of two or more selected from ethyl) amine, N- (hydroxymethoxymethyl) -N- (hydroxyethyl) -N- (2-hydroxypropyl) amine of the formula Cement additives to improve. [Formula 2]

[Formula 3]

[Formula 4]

The method of claim 1, The additive is a cement additive used as a grinding aid when grinding cement clinker, which is used in an amount of 0.0005 to 5 parts by weight based on 100 parts by weight of cement clinker. delete The method of claim 1, The additive is a cement admixture, the cement additive used in 0.1 to 50% by weight of the total amount of the cement admixture. delete Cement composition containing the cement additive according to any one of claims 1, 2 or 4.