KR102700622B1 - Primer for concrete coating and concrete coating method using thereof - Google Patents

Abstract

According to the invention, a primer for concrete painting is provided, comprising: 100 parts by weight of a penetrating mixture in which lithium silicate and potassium silicate are mixed in a volume ratio of 5 to 8: 2 to 5; and a water-repellent mixture in which 5 to 20 parts by weight of alkyltriethoxysilane, 0.5 to 10 parts by weight of nitrite, and 0.01 to 0.05 parts by weight of chloride are mixed based on 100 parts by weight of the penetrating mixture, characterized in that the penetrating mixture and the water-repellent mixture are mixed in a volume ratio of 1:1 to 1:2 and manufactured as a one-component type.

Description

Primer for concrete coating and concrete coating method using the same {Primer for concrete coating and concrete coating method using the same}

The present invention relates to a primer for concrete painting and a method for painting concrete using the same, and more specifically, to a primer for concrete painting and a method for painting concrete using the same, which forms a neutralization prevention layer on a concrete base using a penetrable mixture having excellent penetrability and a water-repellent mixture having excellent water-repellency, and provides a protective coating so as to minimize the shortening of the lifespan of the concrete base due to neutralization, deterioration and oxidation of the concrete base, and at the same time, suppresses the generation of bubbles and pinholes when constructing a waterproofing layer using a waterproofing agent, thereby maximizing the functions of the waterproofing layer, such as crack resistance and oxidation resistance.

Generally, floors of underground parking lots, rooftops, or water purification plants are finished with a waterproofing layer using a waterproofing film to prevent concrete from being crushed and dusted, and to maintain an aesthetically pleasing environment.

Waterproofing agents are mainly composed of organic substances such as epoxy or urethane, or inorganic substances such as powder hardeners.

Here, organic waterproofing coatings such as epoxy or urethane are regulated by international standards and environmental laws that require waterproofing coating layers applied to underground parking lots, etc. to be made of non-combustible materials, as toxic gases are generated in the event of a fire.

In addition, inorganic waterproofing agents such as powder hardeners were introduced from Japan in the early 1980s and were well-received when applied to underground parking lots, but due to the poor quality of domestic production, such as the unsightly appearance, unstable color, weak durability, and low workability using conventional methods, they failed to secure market demand and were eliminated from the mid-1990s.

In addition, in the 1980s, a waterproofing film called cation flooring was introduced in Japan. In the case of cation flooring, since it has an organic/inorganic composite material that fuses cement components and cation resin, it does not meet the international standards or environmental laws that require that the waterproofing film be a non-combustible material, as mentioned above. However, it is still recognized as an inorganic waterproofing film and has been used in floor construction for decades due to its non-combustibility and environmental friendliness.

Meanwhile, in the case of the above-mentioned waterproofing coating, when the composition of the waterproofing coating penetrates into the interior of the concrete matrix when the waterproofing coating is applied to the concrete surface at a predetermined thickness to provide a waterproofing coating layer, air bubbles are continuously generated during construction or the hardening process, and as a result, pinholes are generated in the waterproofing coating layer, causing cracks, and as a result, the concrete begins to deteriorate again, resulting in a decrease in crack resistance, freeze resistance, aging resistance, and oxidation resistance.

Accordingly, there is an urgent need for a concrete painting primer that can penetrate deep into the surface of concrete to prevent neutralization of the concrete and prevent the waterproofing film from being easily peeled off due to surface lifting or impact during construction of the waterproofing film, and a concrete painting method using the primer.

(Patent Document 0001) Registered Patent 10-1215403

(Patent Document 0002) Registered Patent 10-0192201

(Patent Document 0003) Registered Patent 10-0884015

(Patent Document 0004) Registered Patent 10-0949548

Accordingly, the purpose of the present invention is to provide a primer for concrete painting and a method for painting concrete using the same, which forms a neutralization prevention layer on a concrete base and provides a protective coating using a penetrating mixture having excellent penetrability and a water-repellent mixture having excellent water-repellency, thereby minimizing the shortening of the lifespan of the concrete base due to neutralization, deterioration and oxidation of the concrete base, and at the same time, suppresses the generation of bubbles and pinholes when constructing a waterproofing layer using a waterproofing agent, thereby maximizing the functions of the waterproofing layer such as crack resistance and oxidation resistance.

Meanwhile, the purpose of the present invention is not limited to the purpose mentioned above, and other purposes not mentioned can be clearly understood by those with ordinary skill in the art from the description below.

According to the invention, a primer for concrete painting is provided, comprising: 100 parts by weight of a penetrating mixture in which lithium silicate and potassium silicate are mixed in a volume ratio of 5 to 8: 2 to 5; and a water-repellent mixture in which 5 to 20 parts by weight of alkyltriethoxysilane, 0.5 to 10 parts by weight of nitrite, and 0.01 to 0.05 parts by weight of chloride are mixed based on 100 parts by weight of the penetrating mixture, characterized in that the penetrating mixture and the water-repellent mixture are mixed in a volume ratio of 1:1 to 1:2 and manufactured as a one-component type.

Here, lithium silicate preferably has a molar ratio of silicic acid and lithium of 1:2 to 1:4, potassium silicate preferably has a molar ratio of silicic acid and potassium of 1:4 to 1:6, and lithium silicate and potassium silicate preferably each have particles of 10 nm in size.

In addition, it is preferable that the primer for concrete painting further contains 3 to 10 parts by weight of a catalyst or accelerator, CaCl2·2H2O, based on 100 parts by weight of the penetrating mixture.

Meanwhile, according to the present invention, a method for painting concrete using a concrete painting primer is provided, including a step of cleaning and treating a concrete surface; a step of allowing the concrete painting primer to penetrate into a concrete matrix to coat a neutralization prevention layer; and a step of applying a coating waterproofing agent to an upper surface of the neutralization prevention layer of the concrete matrix to coat a coating waterproofing layer.

Therefore, according to the present invention, a neutralization prevention layer is formed on the concrete matrix and a protective coating is applied using a penetrative mixture having excellent penetrability and a water-repellent mixture having excellent water-repellency, thereby minimizing the shortening of the lifespan of the concrete matrix due to neutralization, deterioration, and oxidation, and at the same time, when constructing a waterproofing layer using a waterproofing agent, the generation of bubbles and pinholes is suppressed, thereby maximizing the functions of the waterproofing layer, such as crack resistance and oxidation resistance.

Meanwhile, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those with ordinary skill in the art from the description of the claims.

Hereinafter, preferred embodiments of the present invention will be described in detail.

A primer for concrete painting according to a preferred embodiment of the present invention comprises a penetrating mixture in which lithium silicate and potassium silicate are mixed in a predetermined volume ratio, and a water-repellent mixture to which alkyltriethoxysilane, nitrite, and chloride are added, and the penetrating mixture and the water-repellent mixture are mixed.

More specifically, the concrete coating primer of the present invention comprises 100 parts by weight of a penetrating mixture in which lithium silicate and potassium silicate are mixed in a volume ratio of 5 to 8: 2 to 5, and a water-repellent mixture in which 5 to 20 parts by weight of alkyltriethoxysilane, 0.5 to 10 parts by weight of nitrite, and 0.01 to 0.05 parts by weight of chloride are mixed based on 100 parts by weight of the penetrating mixture, and the penetrating mixture and the water-repellent mixture are mixed in a volume ratio of 1:1 to 1:2 to produce a one-component type.

Lithium silicate, together with potassium silicate, is homogeneously dispersed in a state of rapid penetration deep into the matrix or pores of concrete, thereby improving the density, durability, and waterproofness of concrete, preventing neutralization of the matrix of concrete, and suppressing elastic deformation.

Here, lithium silicate has a molar ratio of silicic acid and lithium of 1:2 to 1:4. If the molar ratio is less than 1:2, silicic acid is not sufficiently added, so that the effect of improving the strength of the concrete is not sufficiently secured, resulting in reduced durability and waterproofing, and if the molar ratio exceeds 1:4, an overreaction occurs on the surface of the concrete, granules are generated, which hinders uniform penetration and causes deoxidation or formation of sediments, resulting in defects. Therefore, it is preferable to have the molar ratio as above.

Potassium silicate, together with lithium silicate, enhances the strength of concrete, increases surface hardness, prevents cracking, and improves chemical resistance by quickly penetrating deep into the concrete body or pores, thereby preventing neutralization of the concrete matrix and ensuring sufficient adhesion when coating the concrete surface with a water-repellent mixture.

Here, potassium silicate has a molar ratio of silicic acid and potassium of 1:4 to 1:6. If the molar ratio is less than 1:4, potassium is applied excessively and the silicic acid does not penetrate into the concrete, so that hardening takes a long time. If the molar ratio exceeds 1:6, the concrete is not sufficiently protected from moisture, durability is not improved, and defects are caused on the surface of the concrete. Therefore, it is preferable to have the molar ratio as above.

Meanwhile, lithium silicate and potassium silicate are used to produce a penetrative mixture that improves the strength and durability of concrete by forming bonds in the form of silicate lattice and calcium silicate through a silicate reaction when penetrating the concrete matrix, that is, a chemical interaction between silicate and calcium hydroxide and other substances in the concrete. More preferably, the mixture has particles of 10 nm in size, so that it naturally penetrates the concrete matrix even at a room temperature of 20°C and reacts with calcium hydroxide and hardens to form a gel.

Additionally, lithium silicate and potassium silicate are mixed in volume ratios of 5:5, 6:4, 7:3, and 8:2.

Here, lithium silicate and potassium silicate are added in a volume ratio of at least 1 to 4 times that of lithium silicate compared to potassium silicate. However, if the volume ratio of lithium silicate is less than 1 (for example, if lithium silicate and potassium silicate have a volume ratio of 4:6), the permeability is not secured, so there is a problem that it does not penetrate deeply enough into the concrete matrix or pores but rather is discharged to the outside from the concrete matrix. If the volume ratio of lithium silicate exceeds 4 times (for example, if lithium silicate and potassium silicate have a volume ratio of 9:1), the permeability is too strong and penetrates deeper than the inherent material rejection point of the concrete matrix, making it difficult to accurately evaluate the structural stability of the concrete matrix and durability, etc., and since the amount of potassium silicate added is small and the amount of silicate ions is insufficient, it does not harden at room temperature, so a separate heat hardening means is required, which reduces workability. Therefore, the limited volume ratio as described above is preferred. It is desirable.

Alkyltriethoxysilane is used to improve the adhesion, durability and waterproofing of the neutralization prevention layer when manufactured as a water-repellent mixture with nitrite and chloride and when penetrating or spraying into the concrete matrix or pores, more preferably, it is good to have particles of 20 nm in size so that the penetrating mixture can penetrate into the micro-pores of the concrete.

In addition, when alkyltriethoxysilane is manufactured as a water-repellent mixture together with nitrite and chloride, the reaction period or reaction time of the water-repellent mixture can be such that the penetrable mixture penetrates into the pores of the concrete surface to a predetermined depth and then hardens, while a neutralization prevention layer of a predetermined thickness is secured, thereby maintaining waterproofing properties.

Here, alkyltriethoxysilane is added in an amount of 5 to 20 parts by weight per 100 parts by weight of the penetrating mixture. If it is less than 5 parts by weight, it is difficult to form a sufficiently thick anti-neutralization layer on the surface of the concrete and it does not react with alkaline substances inside the concrete, thereby reducing the anti-neutralization effect. If it exceeds 20 parts by weight, the pH value of the concrete increases, which has a negative effect on the formation of the anti-neutralization layer and the penetrating mixture does not penetrate deeply into the pores of the concrete but is concentrated only on the surface. Therefore, it is desirable to have a limited weight amount as described above.

When manufactured as a water-repellent mixture with alkyltriethoxysilane and chloride, nitrite provides the function of promoting oxidation and reduction during a chemical reaction with calcium hydroxide after the penetrating mixture has penetrated into the pores of concrete, thereby promoting a chemical reaction between concrete and silicate penetrant through calcium ions, thereby forming calcium silicate on the concrete surface or in the pores.

Here, nitrite is added in an amount of 0.5 to 10 parts by weight per 100 parts by weight of the penetrative mixture. If it is less than 0.5 parts by weight, calcium and anions are insufficient, so that the silicate reaction does not occur smoothly. If it exceeds 10 parts by weight, a substance combined with calcium and anions precipitates in granule form or the reaction is concentrated on the concrete surface, so that the properties of the concrete change and the appearance deteriorates. Therefore, it is preferable to have a limited amount by weight as described above.

Chloride may be known as having the function of promoting penetration of a penetrable mixture, inducing neutralization, and improving the adhesion and durability of a neutralization prevention layer when manufactured as a water-repellent mixture together with alkyltriethoxysilane and nitrite.

Here, chloride is added in an amount of 0.01 to 0.05 parts by weight per 100 parts by weight of the penetrating mixture. If it is less than 0.01 parts by weight, the silicate ions of the penetrating mixture cannot penetrate deeply into the pores of the concrete, so that the silicate reaction is reduced and the adhesion of the neutralization prevention layer is reduced. If it exceeds 0.05 parts by weight, it interacts with the reinforcing bars in the concrete, causing corrosion and reducing the penetrability and adhesion of the penetrating mixture. Therefore, it is preferable to have the weight parts as above.

Meanwhile, in the present invention, it is preferable that the concrete painting primer be added with 3 to 10 parts by weight of CaCl2·2H2O, which is a catalyst or accelerator that provides permeability and water repellency when forming a neutralization prevention layer through a penetrable mixture and a water-repellent mixture, so that a chemical reaction between the concrete and the silicate penetrating material is promoted through calcium ions, thereby forming calcium silicate on the concrete surface or in pores.

Here, the carton is added in an amount of 3 to 10 parts by weight per 100 parts by weight of the penetrating mixture. If it is less than 3 parts by weight, the amount of calcium chloride is insufficient, so that the silicate reaction does not occur smoothly, the gelation of the penetrating mixture at room temperature (20°C) becomes difficult, and the moisture removal function and freezing point depression function are not sufficiently exerted. If it exceeds 10 parts by weight, the calcium chloride precipitates in the form of granules or the reaction is concentrated on the surface of the concrete, so that the properties of the concrete change and the appearance deteriorates. Therefore, it is preferable to have a limited weight part as described above.

Meanwhile, in the present invention, the penetrable mixture and the water-repellent mixture are mixed in a volume ratio of 1:1 to 1:2 to manufacture a one-component type. However, if the volume ratio of the water-repellent mixture is less than 1 with respect to the volume ratio of the penetrable mixture, the neutralization prevention property of the concrete surface is not sufficiently secured, so that the durability of the concrete is not improved. In addition, if the volume ratio of the water-repellent mixture exceeds 2 with respect to the volume ratio of the penetrable mixture, a large amount of a composition such as chloride is added, so that the inside of the concrete is easily neutralized, and thus an abnormal chemical reaction occurs, which may cause a pinhole problem due to the generation of bubbles during construction of the waterproofing layer using the waterproofing coating agent. Therefore, it is preferable to have a limited volume ratio as described above.

Hereinafter, the effect of a primer for concrete painting according to a preferred embodiment of the present invention will be described through specific examples.

A one-component type concrete coating primer is manufactured by mixing 100 parts by weight of a penetrating mixture in which lithium silicate and potassium silicate are mixed in a volume ratio of 5:5, and a water-repellent mixture in which 3 parts by weight of alkyltriethoxysilane, 0.1 parts by weight of nitrite, and 0.009 parts by weight of chloride are mixed based on 100 parts by weight of the penetrating mixture, and the penetrating mixture and the water-repellent mixture are mixed in a volume ratio of 1:0.8.

A one-component type concrete coating primer is manufactured by mixing 100 parts by weight of a penetrating mixture in which lithium silicate and potassium silicate are mixed in a volume ratio of 7:3, and a water-repellent mixture in which 15 parts by weight of alkyltriethoxysilane, 7 parts by weight of nitrite, and 0.03 parts by weight of chloride are mixed based on 100 parts by weight of the penetrating mixture, and the penetrating mixture and the water-repellent mixture are mixed in a volume ratio of 1:1.5.

A one-component type concrete coating primer is manufactured by mixing 100 parts by weight of a penetrating mixture in which lithium silicate and potassium silicate are mixed in a volume ratio of 8:2, and a water-repellent mixture in which 30 parts by weight of alkyltriethoxysilane, 15 parts by weight of nitrite, and 0.55 parts by weight of chloride are mixed based on 100 parts by weight of the penetrating mixture, and the penetrating mixture and the water-repellent mixture are mixed in a volume ratio of 1:2.1.

Meanwhile, in order to evaluate the performance of the concrete painting primer of each of the above examples, test pieces were manufactured as described above, and then, using Company A's concrete painting primer as a comparative example, the freeze-thaw resistance through KSF 2456, the surface peeling resistance through ASTC 672, the chloride ion penetration resistance through KSF 2711, and the curing time at room temperature and the water absorption resistance (water absorption after 5 hours of submerging a concrete sphere coated with the examples and comparative examples in water) were evaluated. The results are shown in Table 1 below.

Therefore, it can be seen that the concrete painting primer according to a preferred embodiment of the present invention has an excellent neutralization prevention effect through excellent freeze-thaw resistance, surface peeling resistance, chloride ion penetration resistance, room temperature curing, and water absorption resistance compared to the conventional concrete painting primer, as shown in Table 1 above.

In addition, in order to evaluate the performance of the concrete painting primer of Example 2 among each of the above examples, test pieces were prepared as described above, and then, using a known epoxy/acrylic coating agent as a comparative example, penetration depth, UV protection, service life, chloride ion reduction and moisture absorption rate reduction effects, water vapor transmission rate, crack prevention, and deicing salt corrosion prevention, etc. were evaluated, and the results are shown in Table 2 below.

Therefore, it can be seen that the concrete painting primer according to a preferred embodiment of the present invention provides excellent penetration depth, UV protection, chloride ion reduction and moisture absorption rate reduction, water vapor transmission rate, crack prevention, and deicing salt corrosion prevention effects compared to conventional epoxy/acrylic coating agents, as shown in Table 2 above.

Meanwhile, a concrete painting method using a concrete painting primer according to a preferred embodiment of the present invention is as follows.

First, the concrete surface of an underground parking lot, rooftop, or water purification plant, where concrete painting is to be performed using a concrete painting primer, is cleaned and treated.

Here, cleaning of the concrete surface includes removing dust, contaminants, or oil adhering to the concrete surface and smoothing out the protrusions of the surface to be constructed.

Thereafter, a primer for concrete painting corresponding to Examples 1 to 3 is manufactured.

Thereafter, a concrete painting primer is applied or sprayed onto the surface-treated construction surface by means of a coating or spraying means, or is hardened after penetrating into the micropores, thereby completing the construction of a neutralization prevention layer on the concrete matrix or surface.

Here, the concrete painting primer is applied twice at 200 ml to 300 ml per unit area (m^2) of concrete through a low-pressure (75 kPa) automatic spray device. At this time, it is preferable that the working temperature be 20℃ and the relative humidity be 55%, and then the primer be applied once more after curing for 7 hours.

Afterwards, a known waterproofing agent is applied to the upper surface of the neutralization prevention layer to construct a waterproofing layer.

Meanwhile, a waterproofing film was constructed by applying a waterproofing film to a concrete surface on which a primer layer was constructed using a concrete painting primer according to a comparative example, and a waterproofing film was constructed by applying a waterproofing film to a concrete surface on which a neutralization prevention layer was constructed using a concrete painting primer according to Example 2. The construction process, occurrence of pinholes, color stability, gloss, and contamination resistance, etc. were compared, and the results are shown in Table 3 in photographs.

Accordingly, according to Table 3, it was confirmed that the waterproof coating layer applied to the concrete surface on which the neutralization prevention layer was applied using the concrete painting primer according to Example 2 had excellent color stability, gloss, and contamination resistance without generating pinholes, compared to the waterproof coating layer applied to the concrete surface on which the primer layer was applied using the concrete painting primer according to the comparative example.

Therefore, according to the present invention, a neutralization prevention layer is formed on the concrete matrix and a protective coating is applied using a penetrative mixture having excellent penetrability and a water-repellent mixture having excellent water-repellency, thereby minimizing the shortening of the lifespan of the concrete matrix due to neutralization, deterioration, and oxidation, and at the same time, when constructing a waterproofing layer using a waterproofing agent, the generation of bubbles and pinholes is suppressed, thereby maximizing the functions of the waterproofing layer, such as crack resistance and oxidation resistance.

Although the preferred embodiments of the present invention have been described with reference to the attached drawings, those skilled in the art will understand that the present invention can be implemented in other specific forms because various substitutions, modifications, and changes can be made without departing from the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims (4)

100 parts by weight of a penetrative mixture comprising lithium silicate and potassium silicate in a volume ratio of 5 to 8: 2 to 5;
Based on 100 parts by weight of penetrating mixture,
A water-repellent mixture comprising 5 to 20 parts by weight of alkyltriethoxysilane, 0.5 to 10 parts by weight of nitrite, and 0.01 to 0.05 parts by weight of chloride,
A primer for concrete painting, characterized in that it is manufactured as a one-component type by mixing a penetrating mixture and a water-repellent mixture in a volume ratio of 1:1 to 1:2. In the first paragraph,
Lithium silicate has a molar ratio of silicate and lithium of 1:2 to 1:4.
Potassium silicate has a molar ratio of silicic acid and potassium of 1:4 to 1:6.
A primer for concrete painting, characterized in that lithium silicate and potassium silicate each have particles of 10 nm in size. In the first paragraph,
Based on 100 parts by weight of penetrating mixture,
A primer for concrete painting, characterized in that it further contains 3 to 10 parts by weight of carton (CaCl2·2H2O), which is a catalyst or accelerator. The step of cleaning and treating the concrete surface;
A step in which a concrete painting primer according to any one of claims 1 to 3 penetrates into a concrete matrix and a neutralization prevention layer is coated;
A method for painting concrete using a primer for concrete painting, characterized in that it includes a step of coating a waterproofing agent on the upper surface of a neutralization prevention layer of a concrete base material and coating the waterproofing layer.