KR20150098114A - Composition for Topcoating, Manufacturing Process thereof and Coating Process of Concrete Using the Same - Google Patents

Abstract

The present invention relates to a composition for top coating, a manufacturing method thereof, and a coating method of concrete using the same. The present invention relates to a composition for top coating the concrete wall side in a water supply storage facility and, more specifically, to a composition for top coating applied on the top after coating concrete with a composition for coating concrete using the buried and left oyster shell as a raw material, a manufacturing method thereof, and a composition for coating the concrete and a method for coating concrete using a composition for top coating.

Description

TECHNICAL FIELD The present invention relates to a composition for top coating, a method for producing the same, and a concrete coating method using the composition.

The present invention relates to a composition for top coating, a process for producing the same, and a concrete coating method using the same.

The present invention relates to a composition for top coating of a concrete wall surface of a water storage facility, and more particularly, to a composition for coating a concrete wall with a composition for concrete coating using a buried oyster shell as a raw material, A method for producing the same, and a concrete coating method using the concrete coating composition and the top coating composition.

The present invention relates to a top coating composition suitable for an environmentally friendly concrete coating composition utilizing an oyster shell, which is a waste resource occurring in a coastal area, a method for producing the same, and a concrete coating method using the concrete coating composition and the top coating composition .

Oyster shells are produced in the southern coastal area around 28-30,000 tons per year. However, only about 10% of the total amount is recycled as raw materials for fertilizer and calcium, and the remaining oyster shells are buried or illegally left in the vicinity. This is another serious problem of marine pollutants such as odor generation.

The oyster shell is generally composed of calcium carbonate (CaCO ₃ ) in an amount of 90% or more, and it contains calcium phosphate (calcium phosphate) like human bone due to its phosphorus content. So that it is possible to prevent cracking during coating.

On the other hand, the water storage facilities are mainly made of concrete, and their surface is coated with epoxy resin. Such a water storage facility should be cleaned regularly, but the coating layer may peel off due to desorption of epoxy resin during washing. In addition, epoxy resins are made by reacting bisphenol-A with epichlorohydrin in the presence of sodium hydroxide. Bisphenol-A is very harmful to human body.

These solve the problem to recently, but a lot of effort to ensure drinking water stability, such as attaching the PE, a glass plate or stainless steel plate to a concrete wall by replaced with an epoxy resin coating as above, the coating area of 1 m ² epoxy resin per The cost of PE, glass, and stainless steel is 20-30,000 won, which is very economical.

The adhesive method is usually composed of harmful substances and there is a risk of elution. In the screwing method, the concrete wall is cracked during the drilling process. There is a drawback that water can seep into and cause pollution, and there are many problems that are currently commercially applied from the economical side and the practical side.

Korean Patent No. 968108, which was invented by the inventors of the present invention, discloses an eco-friendly coating material in which an inorganic component such as oyster shell and a polymer are mixed, but it is composed of a single layer, and improvement of durability is required. However, such a coating film containing a large amount of inorganic components and a top coating having excellent adhesion property have not been reported yet, and development thereof is urgently required.

Korean Patent No. 968108

SUMMARY OF THE INVENTION It is an object of the present invention to provide a composition for top coating excellent in adhesion to a coating film containing a large amount of an inorganic component.

Another object of the present invention is to provide a method for producing the composition for top coating.

Another object of the present invention is to provide a concrete coating composition and a concrete coating method using the composition for top coating.

The composition for top coating of the present invention, in order to achieve the above-mentioned object,

100 parts by weight of water,

10.5 to 20.0 parts by weight of metal silicon,

8.0 to 15.0 parts by weight of sodium hydroxide, and

6.5 to 13.0 parts by weight of borax

And a control unit.

On the other hand, the method for producing the composition for top coating of the present invention

Adding 4.8 to 9.5 parts by weight of metal silicon per 100 parts by weight of water and heating to 45 to 60 DEG C, and

Adding 3.7 to 7.0 parts by weight of sodium hydroxide and 3.0 to 6.0 parts by weight of sodium hydroxide per 100 parts by weight of the water to the mixture of water and metal silicon, heating the mixture to 75 to 90 DEG C, and maintaining the mixture for 2 hours and 30 minutes to 4 hours

And a control unit.

Meanwhile, the top coating composition of the present invention is characterized in that the top coating composition is prepared by the method for producing the top coating composition.

Meanwhile, the concrete coating method of the present invention is a method of coating a concrete with an oyster shell of 5 to 45 wt% (total weight ratio is equal to the following), 20 to 40 wt% of a polyacrylic ester emulsion, 10 to 15 wt% 5 to 10% by weight of meta-kaolin, 5 to 10% by weight of Al ₂ O ₃ , and 10 to 20% by weight of silica sand, and

Coating the concrete coating composition coated on the concrete with the top coating composition of claim 1 or claim 3

And a control unit.

Further, the concrete coating composition

Oyster shell powder manufacturing process in which oyster shells are washed, fired and pulverized to obtain oyster shell powder;

An intermediate composition preparing step of mixing an oyster shell powder with white cement, meta kaolin, Al ₂ O ₃ and silica sand as a dry beam to obtain an intermediate composition; And

A mixing step of adding a polyacrylic ester emulsion and water to the intermediate composition

Lt; / RTI >

The oyster shell powder is washed with water to remove salt and foreign matter, dried, calcined at 600 to 800 ° C for 1 to 4 hours, and pulverized to 2 to 200 μm.

The intermediate product manufacturing process comprises the steps of: 5 to 45 wt% oyster shell (total weight ratio is equal to), 5 to 15 wt% of white cement, 5 to 10 wt% of meta kaolin, 5 to 10 wt% of Al ₂ O ₃ , And 10 to 20% by weight of the polyvinyl alcohol may be mixed in a dry beaker.

As described above, the composition for top coating of the present invention exhibits excellent adhesiveness to a concrete coating composition for concrete coating recycled waste resources of oyster shells compared to the prior art, thereby protecting the coating film for concrete coating. As a result, Thereby improving the durability of the coating film. Furthermore, by coating the concrete with the concrete coating composition containing the oyster shell, it is economically advantageous from the viewpoint of cost, and the adhesion of the entire coat is improved as compared with the prior art. The environmentally friendly and harmless ceramic material which does not dissolve the components of the coating film in the water and does not contaminate the tap water and does not erode the waterproof layer by washing and chlorine component of the water storage facility can be used to enhance the stability as drinking water have. Furthermore, it is possible to utilize waste resources at the same time as reducing marine pollution, and it can be utilized as a permanent alternative resource.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing the adhesion strength of epoxy and the concrete coating composition (A) of Production Example 1 of the present invention and the concrete coating composition (B) of Production Example 2. FIG.
2 is a comparative test chart of the acidity of water with time in immersing the concrete coating composition (A) of Production Example 1 of the present invention and the concrete coating composition (B) of Production Example 2 of the present invention in ordinary tap water.
3 is a comparison test for dissolving bisphenol-A from an epoxy, a concrete coating composition (A) of Production Example 1 of the present invention, and a test piece coated with the concrete coating composition (B) of Production Example 2;

Hereinafter, preferred embodiments of the present invention will be described in detail. In the following description, numerous specific details, such as specific elements, are set forth in order to provide a thorough understanding of the present invention, and it is to be understood that the present invention may be practiced without these specific details, It will be obvious to those who have knowledge of. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

The composition for top coating of the present invention is characterized by containing 100 parts by weight of water, 10.5 to 20.0 parts by weight of metal silicon, 8.0 to 15.0 parts by weight of sodium hydroxide, and 6.5 to 13.0 parts by weight of borax.

Here, metal silicon refers to pure silicon from which oxygen molecules have been removed by treating silicon dioxide at a high temperature. It has a metallic nature and is used in additives such as aluminum alloys, organic silicon, semiconductors, photovoltaic industry, steel smelting, precision ceramics In the present invention, the composition for top coating serves to enhance the durability of the cured top coat layer.

The metal silicone preferably contains 10.5 to 20.0 parts by weight per 100 parts by weight of the water constituting the topcoat composition of the present invention. If it is less than the above range, the durability of the topcoat layer is lowered. On the other hand, And the compatibility and reactivity with the catalyst are deteriorated.

Sodium hydroxide functions to generate salts to dissolve the components constituting the top coating layer of the present invention in water.

The sodium hydroxide preferably contains 8.0 to 15.0 parts by weight per 100 parts by weight of the water constituting the topcoat composition of the present invention. If less than the above range, salt formation is not smoothly performed, If it exceeds the above range, miscibility between the constituents is deteriorated.

On the other hand, borax is also called borax, and its chemical name is sodium tetraborate 10 hydrate. Boric acid, boric acid salt, borosilicate glass, special glass, ceramics glaze, medicine, cosmetics, detergent and the like. In the present invention, water resistance and heat resistance are imparted to the top coating layer.

The borax is preferably contained in an amount of 6.5 to 13.0 parts by weight per 100 parts by weight of the water constituting the topcoat composition of the present invention. If it is less than the above range, it is difficult to sufficiently exhibit the water resistance and heat resistance. Conversely, There is a problem that the miscibility between the components is deteriorated.

Meanwhile, the method for preparing the top coating composition of the present invention starts with adding 4.8 to 9.5 parts by weight of metal silicon per 100 parts by weight of water and heating to 45 to 60 ° C. When the temperature of the mixture of water and the metal silicon reaches 45 to 60 캜, 3.7 to 7.0 parts by weight of sodium hydroxide and 3.0 to 6.0 parts by weight of sodium hydroxide are added per 100 parts by weight of water constituting the mixture, After heating, the mixture is maintained for 2 hours and 30 minutes to 4 hours to prepare a topcoat composition of the present invention.

If the heating temperature is lower than the above range after the addition of sodium hydroxide and borax, the reaction rate between the components decreases. On the contrary, if the heating temperature exceeds the above range, the reaction does not proceed as intended and the physical properties of the desired top coating layer none.

On the other hand, the composition for top coating of the present invention is characterized by being produced by the above-mentioned production method.

The top coating composition of the present invention is coated on the coating film for concrete coating composition containing oyster shell as described above, and is strongly bonded to the coating film, thereby protecting the coating film and improving durability.

Here, the composition for coating with concrete is stabilized by a chemical bond between acrylic and non-gelled calcium hydroxide together with hydration reaction, and has a reaction of encapsulating the surface of acrylic by the reaction of acryl and the surface of cement particles.

In the concrete coating method of the present invention, the concrete coating composition, which is primarily applied on the concrete wall surface of the water storage facility, is composed of oyster shell powder, bag cement, meta kaolin, Al ₂ O ₃ , silica sand, poly Acrylic ester emulsion and water are mixed to have a polymer function and a surface effect of ceramic.

Ratio in the composition, oyster shell is 5 to 45% by weight (the total weight; equal to or less), white cement is from 5 to 15% by weight, metakaolin is from 5 to 10% by weight, Al ₂ O ₃ from 5 to 10 10 to 20% by weight of silica, 20 to 40% by weight of polyacrylic ester emulsion, and 10 to 15% by weight of water.

A method for producing a concrete coating composition having the above composition comprises:

Oyster shell powder processing step in which oyster shells are washed, fired and pulverized;

An intermediate composition preparing step of mixing an oyster shell powder with white cement, meta kaolin, Al ₂ O ₃ and silica sand by dry blending to obtain an intermediate composition; And

A mixing step of adding water and a polyacrylic ester emulsion to the intermediate composition;

.

Among them, oyster shell powder, which is washed, fired and pulverized, is washed with water to remove salts and foreign substances, washed with water, dried, calcined at 600 to 800 ° C for 1 to 4 hours, And a step of pulverizing it to 200 mu m.

In the intermediate product production process, 5 to 15% by weight of white cement, 5 to 10% by weight of meta kaolin, 5 to 10% by weight of Al ₂ O ₃ , 5 to 10% by weight of white cement, And 10 to 20% by weight of the polylactic acid in a dry bean beam.

The above-mentioned composition for concrete coating is characterized in that a hydration reaction in which water and cement particles are bound to each other gradually proceeds to increase the pot life, and to obtain a hydration reaction between water and cement particles having a structure stabilized by chemical bonding with un- And a coating agent having a surface effect of a polymer and a ceramic material is provided by allowing the surface of the concrete to react with the surface of the cement particle to have a reaction to surround the surface of the acrylic with the acrylic film To improve the stability of water quality, to reduce the cost due to the utilization of waste resources, to protect the wall to be coated due to high water tightness, and to have a ventilation performance so that the peeling phenomenon does not occur even after a long period of time ≪ / RTI > provides a coating.

Table 1 shows the composition of each constituent element.

Mixing ratio of materials used Ingredients Oyster shell Polyacrylic ester emulsion water White cement Meta kaolin Al ₂ O ₃ Silica sand weight% 5-45 20-40 10-15 5-15 5-10 5-10 10-20

The oyster shell was used for the purpose of improving the viscosity, the surface hardness and the adhesive force, and showed the best performance at 5 to 45 wt%. However, if it is lower than the lower limit, there is a problem that the adhesion strength and the durability of the coating agent are reduced. If the upper limit is larger than the lower limit, there is a problem that the ingredients are not uniformly dispersed in the mixing.

The pulley acrylic ester emulsion is prepared for the purpose of adhesiveness, water tightness and water resistance, and when it is 20 to 40% by weight, it has the best adhesiveness, water tightness and waterproofness. However, if it is smaller than the above lower limit value, there is a problem in crack followability and adhesion, and if it is larger than the upper limit value, there is a problem in strength, so the numerical range is limited as described above.

The water is prepared for hydration reaction with cement, and exhibits the best performance in the range of 10 to 15 wt%. However, when it is lower than the lower limit value, there is a problem that the hardness is weak, and when it is larger than the upper limit value, the pH is considerably high, which limits the numerical range as described above.

The meta-kaolin is designed to improve the strength, density and durability of cement by changing calcium hydroxide to calcium silicate hydrate during the cement hydration reaction, and exhibits the best performance at 5 to 10 wt%. However, the durability enhancement function is insufficient when the lower limit value is less than the upper limit value, and the longevity time is short when the upper limit value is larger than the upper limit value.

The silica sand is used for the purpose of preventing cracks as a filler of water, cement or other ceramics, and exhibits the best performance when it is 5 to 10 wt%. However, if it is smaller than the above lower limit value, there is a problem that the effect of crack reduction is insignificant. If it is larger than the upper limit value, there is a problem of material separation and dispersibility.

Hereinafter, the characteristics of the oyster shell and the polyacrylic ester emulsion, which are the main materials constituting the concrete coating composition, will be described in more detail.

end. Oyster shell

The oyster shell is a powder obtained by washing with water to remove salts and foreign substances, followed by drying in a drier at 100 ° C for 24 hours, calcining at 600 to 800 ° C for 1 to 4 hours, and pulverization at 2 to 200 μm do. When the oyster shells were fired in an electric furnace, the removal of pores and organic substances on the surface was satisfactory during firing at 600 ° C. The oyster shell was pyrolyzed with calcium carbonate structure and calcium oxide (CaO) structure at 700 ° C. The two states were mixed, and when the oyster shell was calcined at 900 ℃, the complete calcium oxide (CaO) structure appeared. Therefore, the most preferable firing temperature is 600 DEG C, and the firing time of about 2 hours is remarkably effective. The physicochemical properties of oyster shells are shown in Table 2.

Physicochemical composition of oyster shell Exterior importance chief ingredient Specific surface area Pore size
(Pore Size) Porosity
(Pore Volume) Off-white solid 2.62 CaCO ₃ (92.08%) 329 m ² / g 3.44 Å 0.25 cc / g

I. Polyacrylic ester emulsion

The emulsion used in the composition for coating concrete has a good compatibility with cement, and physical properties are as follows.

The reaction mechanism when mixed with cement can be classified into two types. First, hydration reaction between water and dry cement-ceramic particles and reaction between second acrylic and cement surface can be categorized.

In other words, it does not interfere with the hydration reaction of water and cement, but gradually combines with the cement to increase the pot life, and the surface is surrounded by the acrylic film. And has a structure stabilized by the chemical bond between acrylic and non-gelled calcium hydroxide.

The physical properties of the polyacrylic ester emulsion are shown in Table 3, and the chemical structure thereof is shown in Chemical Formula 1.

Physical Properties of Polyacrylic Ester Emulsion Exterior importance pH Solids Viscosity (cP) Particle Size (nm) White liquid phase 1.012 7 51 30 100

In the concrete coating method of the present invention, the composition for coating concrete is coated on the inner wall of concrete of a water storage tank such as a water tank to form a base layer coating. When the base layer coating is cured, ≪ / RTI >

Hereinafter, embodiments of the present invention will be described.

Example

Manufacturing example  1: Preparation of composition for concrete coating (1)

Step 1: Oyster shell powder manufacturing process

The oyster shells which were abandoned in the oyster farm were sampled and washed sufficiently to remove the salinity. The washed oyster shells were dried in a dryer at 100 ° C. for 24 hours and then fired in an electric furnace at a temperature of 600 ° C. for 2 hours, Mu] m. The chemical composition of the washed and fired oyster shells is shown in Table 4.

Chemical composition of oyster shell washed (%) ingredient SiO ₂ Al ₂ O ₃ CaCO ₃ K ₂ O Na ₂ O P ₂ O ₅ SrO SO ₃ Fe ₂ O ₃ Ignition content content 0.60 0.93 92.08 0.35 0.98 0.27 0.57 0.41 0.93 43.40

Step 2: Preparation of intermediate composition (A)

30 g of the oyster shell obtained in the first step and 10 g of white cement, 5 g of meta kaolin, 5 g of Al ₂ O ₃ and 10 g of silica sand were mixed in a dry beaker to form an intermediate composition A).

Step 3: Final process

30 g of the intermediate composition (A), 35 g of a polyacrylic ester emulsion prepared by emulsion and 10 g of water were mixed and then continuously mixed for 5 minutes by an electric blender to prepare a concrete coating composition.

Manufacturing example  2: Preparation of composition for concrete coating (2)

Step 1: Oyster shell powder manufacturing process

Was carried out in the same manner as in the first step in Production Example 1.

Step 2: Preparation of intermediate composition (B)

30 g of the oyster shell obtained in the first step and 5 g of white cement as an inorganic material in the form of powder, 5 g of meta kaolin, 5 g of Al ₂ O ₃ and 15 g of silica sand were mixed in a dried state in a dry beaker to prepare a composition B ).

Step 3: Final process

30 g of the intermediate composition (B), 30 g of the polyacrylic ester emulsion and 10 g of water were mixed and then continuously mixed by an electric mixer for 5 minutes to prepare the coating composition of the present invention. Specimens were prepared for bisphenol-A elution test, pH measurement and adhesion strength measurement of the coating composition of the present invention.

Test Example  1: Composition for concrete coating

For the bisphenol-A dissolution test and pH measurement of the composition for concrete coating, a composition for concrete coating was applied on both sides of a glass plate of 200 mm (width) × 70 mm (length) × 3 mm The test specimens for bonding strength measurement were prepared by mixing cement, sand and water in a ratio of 1: 2: 3 to produce a plate having a size of 15 mm (width) × 140 mm (length) × 20 mm (thickness) After curing for a day, the composition for concrete coating was applied by brushing, and the plate coated with the concrete coating composition was cured in a humidity chamber set at a temperature of 20 ± 3 ° C and a humidity of 80% for 13 days, And dried for 24 hours in a laboratory having a humidity of 65 ± 20%.

The dissolution test for bisphenol-A, the pH measurement, and the adhesion strength measurement were carried out as described above.

end. Bond strength

Adhesive strength of the polymeric waterproofing materials generally presented in the Korea Industrial Standard, there are regulations in about 8 to 10 kg _f / cm ² or more, the composition of the present invention showed a high adhesive strength of about 22 to 24 kg _f / cm ² . (See Fig. 1)

I. pH

As a result of measuring the pH of each sample by immersing the glass specimen coated with the composition for concrete coating, the range of pH was about 7.9 to 8.5 at the initial stage, but the measured range was about pH 7.4 to 7.6 Respectively. (See Fig. 2)

All. Dissolving Bisphenol-A

As a result of measuring the bisphenol-A elution concentration of each sample by immersing the glass specimen coated with the composition for concrete coating, 2.8 μg / L of the epoxy resin-coated specimen was eluted, but no concrete coating composition was detected. (See Fig. 3)

In the accompanying drawings, the coating agent according to Preparation Example 1 is indicated as A and the coating agent according to Preparation Example 2 is indicated as B.

The composition for concrete coating is advantageous economically in terms of utilization of waste resources because it has improved adhesion with concrete without the detection of bisphenol-A, which is an environmental hormone, as compared with existing coatings, using an oyster shell as a main raw material, By using the material, the stability as drinking water can be improved. It is also considered to be superior in that it can expand the use of waste resources while reducing marine pollution and utilize it as a permanent alternative resource.

The concrete coating composition may be provided in a completed form, and the intermediate composition (A, B) and the polyacrylic ester emulsion may be separately prepared and used at the construction site.

Example : For top coating  Preparation of composition

After adding 3 kg of metal silicon to 40 kg of water and heating to 55 캜, 2 kg of sodium hydroxide and 2 kg of borax were added, heated to 85 캜 and maintained for 3 hours and 30 minutes, .

Test Example  2: For top coating  Composition

The top coating composition of the above example was coated on the coated coating composition for concrete coating in Test Example 1, and then cured and the adhesion strength was measured.

Composition for concrete coating Bond strength Production Example 1 22 kg _f / cm ² Production Example 2 20 kg _f / cm ²

As can be seen from Table 5, the top coating composition of the present invention exhibited excellent adhesion strength to the coating film for concrete coating composition containing oyster shell, so that the protective coating composition coating film for concrete was excellent. As a result, The durability of the coating film is improved.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of course it is possible. Accordingly, the scope of the present invention should not be construed as being limited to the above-described embodiments, but should be determined by equivalents to the appended claims, as well as the following claims.

Claims (5)

100 parts by weight of water,
10.5 to 20.0 parts by weight of metal silicon,
8.0 to 15.0 parts by weight of sodium hydroxide, and
6.5 to 13.0 parts by weight of borax
≪ / RTI > Adding 4.8 to 9.5 parts by weight of metal silicon per 100 parts by weight of water and heating to 45 to 60 DEG C, and
Adding 3.7 to 7.0 parts by weight of sodium hydroxide and 3.0 to 6.0 parts by weight of sodium hydroxide per 100 parts by weight of the water to the mixture of water and metal silicon, heating the mixture to 75 to 90 DEG C, and maintaining the mixture for 2 hours and 30 minutes to 4 hours
≪ / RTI > A composition for top coating prepared by the method of claim 2. (C) 20 to 40% by weight of polyacrylic ester emulsion, 10 to 15% by weight of water, 5 to 15% by weight of white cement, 5 to 10% by weight of meta kaolin, 5 to 10% by weight of ₂ O ₃ , and 10 to 20% by weight of silica sand, and a step of coating the concrete with a composition for concrete coating comprising
Coating the concrete coating composition coated on the concrete with the top coating composition of claim 1 or claim 3
≪ / RTI > The method of claim 4,
The concrete coating composition comprises
Oyster shell powder manufacturing process in which oyster shells are washed, fired and pulverized to obtain oyster shell powder;
An intermediate composition preparing step of mixing an oyster shell powder with white cement, meta kaolin, Al ₂ O ₃ and silica sand as a dry beam to obtain an intermediate composition; And
A mixing step of adding a polyacrylic ester emulsion and water to the intermediate composition
Lt; / RTI >
The oyster shell powder is washed with water to remove salt and foreign matter, dried, calcined at 600 to 800 ° C for 1 to 4 hours, and pulverized to 2 to 200 μm.
The intermediate product manufacturing process comprises the steps of: 5 to 45 wt% oyster shell (total weight ratio is equal to), 5 to 15 wt% of white cement, 5 to 10 wt% of meta kaolin, 5 to 10 wt% of Al ₂ O ₃ , And 10 to 20% by weight of the composition is mixed with a dry beam.

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