Magnesia-Based Protective Composition and Safety Footplate Applying the Same

Abstract

The present invention relates to an MgO-based phosphate ceramic protective agent for advantageous application to surface protection of work platforms, and more specifically, to a new magnesia protective agent composition capable of ensuring excellent quality in corrosion prevention and walking safety, and a safety platform preferably to which the same is applied. The magnesia protective agent composition according to the present invention is characterized by comprising 30 to 45 parts by weight of porous MgO having macropores of 50 nm or more, 20 to 25 parts by weight of wollastonite, 30 to 45 parts by weight of phosphate, and 1 to 3 parts by weight of boric acid. Here, the phosphate may preferably be composed of 5 to 10 parts by weight of ammonium monophosphate and 25 to 35 parts by weight of potassium monophosphate, and the porous MgO may preferably be prepared by calcining weathered MgO at 1,200 to 1,300°C, and then undergoing a process of maintaining reduced pressure of 50 to 70 kPa when the calcination temperature reaches 770 to 890°C. The safety scaffold according to the present invention is characterized by mixing 15 to 25 parts by weight of water with 100 parts by weight of a magnesia protective agent composition, and the mixture is applied to the work scaffold to a thickness of 350 to 500 μm.

Description

Technology Field

[0001] The present invention relates to an MgO-based phosphate ceramic protective agent for advantageous application to surface protection of work platforms, and more specifically, to a new magnesia protective agent composition capable of ensuring excellent quality in terms of corrosion prevention and walking safety, and to a safety platform preferably to which the same is applied. Background Technology

[0003] Protective agents are applied to metal materials, such as steel, to prevent surface corrosion; a representative example is MgO-based phosphate ceramic protective agent. This agent hardens through the reaction of magnesia and a phosphate-based curing agent, adhering to the substrate through direct ionic bonding to form a film. Such MgO-based phosphate ceramic protective agents offer excellent adhesion and durability, as well as effective corrosion protection. Furthermore, as a fast-curing material, they allow for a single primer application, providing the advantage of reducing construction time and costs.

[0004] Technologies related to MgO-based phosphate ceramic protective agents include Patent No. 10-2641172 and Patent No. 10-2747209. Patent No. 10-2641172 describes a technology for a two-component type protective agent composed of Solution A, which includes magnesia, wollastonite, sodium sulfate, and water, and Solution B, which includes phosphate, boric acid, aluminum phosphate compound, and water. It offers several advantages, such as securing curing time, delaying the time to reach the exothermic temperature, ensuring adhesion performance and corrosion resistance of the coating film, and suppressing the formation of pores in the coating film. Patent No. 10-2747209 is a technology regarding a protective agent of a coating method composed of a magnesia complex in which magnesium hydroxide (Mg(OH)2) is bonded to magnesia (MgO), sodium sulfate, potassium monophosphate, ammonium monophosphate, boric acid, and wollastonite, which has the advantage of being able to be advantageously applied as a fire-resistant paint by ensuring the durability of the coating film even under ultra-high temperature conditions of 1300 degrees or higher.

[0005] The inventors have developed a new protective agent as one of the MgO-based phosphate ceramic protective agents, which is advantageously applied to the surface protection of work platforms where workers frequently walk. Prior art literature

[0007] (Patent Document 0001) KR 10-2641172 B1(Patent Document 0002) KR 10-2747209 B1 The problem to be solved

[0008] The present invention was developed to provide a new protective agent advantageously applied to the surface protection of work platforms. The technical problem is to provide a protective agent composition that exhibits excellent quality, such as securing corrosion prevention performance, ensuring walking stability by minimizing slippage for pedestrians, and improving wear residue characteristics, and to provide a safety platform in which such a composition is preferably applied to a steel work platform. means of solving the problem

[0010] To solve the above-mentioned technical problem, the present invention provides a magnesia protective agent composition characterized by comprising 30 to 45 parts by weight of porous MgO having macropores of 50 nm or more, 20 to 25 parts by weight of wollastonite, 30 to 45 parts by weight of phosphate, and 1 to 3 parts by weight of boric acid. Here, the phosphate may preferably be composed of 5 to 10 parts by weight of ammonium monophosphate and 25 to 35 parts by weight of potassium monophosphate, and the porous MgO may preferably be prepared by calcining weathered MgO at 1,200 to 1,300°C, and then undergoing a process of maintaining reduced pressure of 50 to 70 kPa when the calcination temperature reaches 770 to 890°C.

[0011] In addition, the present invention provides a safety scaffold characterized by 15 to 25 parts by weight of water being mixed with 100 parts by weight of a magnesia protective agent composition, and the mixture being applied to a work scaffold to a thickness of 350 to 500 μm. Effects of the invention

[0013] According to the present invention, by appropriately combining phosphates, etc., with porous MgO having macropores, a protective agent is provided that exhibits excellent quality, such as securing corrosion prevention performance, ensuring walking stability by minimizing slippage of pedestrians, and improving wear residue characteristics; and by preferably applying this protective agent as a coating agent for surface protection of a steel work platform, a safety platform capable of securing safety and durability can be provided. Specific details for implementing the invention

[0015] The present invention relates to an MgO-based phosphate ceramic protective agent for advantageous application to surface protection of steel work platforms, and to a magnesia protective agent composition using porous MgO and a safety platform preferably to which the protective agent composition is applied.

[0017] The protective agent composition according to the present invention comprises 30 to 45 parts by weight of porous MgO having macropores of 50 nm or more, 20 to 25 parts by weight of wollastonite, 30 to 45 parts by weight of phosphate, and 1 to 3 parts by weight of boric acid. In particular, the present invention is characterized by using porous MgO having macropores of 50 nm or more on the internal / surface instead of general MgO having internal / surface pores of 2 nm or less.

[0018] Porous MgO is magnesia (MgO) with macropores of 50 nm or larger, and can be produced by calcining weathered MgO at 1,200–1,300°C for more than 1 hour. When ordinary MgO is exposed to the atmosphere for a long period, it reacts with moisture in the atmosphere to reduce its reactivity; this state is what is referred to as weathered MgO. When this weathered MgO is calcined, hydrates decompose and are expelled, thereby forming macropores on the interior and surface of the MgO. In particular, macropores can be easily formed on the surface of the MgO by instantaneously maintaining reduced pressure (approximately 50–70 kPa gauge pressure) inside the calcination furnace when the temperature reaches 770–890°C during the calcination process. By instantaneously reducing the pressure, hydrates rapidly expand and are expelled during the decomposition process, which leads to the formation of macropores on the surface of the MgO particles. Porous MgO is used in an amount of 30 to 45 parts by weight in the protective agent composition. If less than 30 parts by weight is used, the reaction amount of MgO relative to phosphoric acid is insufficient, leading to a decrease in the curing characteristics of the protective agent and consequently a decrease in the film properties. If more than 45 parts by weight is used, there is a concern that the strength performance will decrease due to an excessive reaction amount of MgO relative to phosphoric acid.

[0019] Wollastonite serves as an inorganic filler to enhance strength performance and contribute to preventing cracking in the protective agent. Wollastonite is used in an amount of 20 to 25 parts by weight in the protective agent composition; if less than 20 parts by weight is used, layer separation is likely to occur when applying the protective agent due to a lack of filler, and if more than 25 parts by weight is used, there is a concern that physical performance may deteriorate due to reduced fluidity of the protective agent and a consequent increase in the amount of water incorporated.

[0020] Phosphates serve as the primary materials that harden by reacting with MgO. Phosphates are used in an amount of 30 to 45 parts by weight in the protective agent composition, a result derived from considerations such as reactivity with MgO and the hardening speed. Ammonium monophosphate and potassium monophosphate can preferably be selected as the phosphates. Ammonium monophosphate is preferably used in an amount of 5 to 10 parts by weight in the protective agent composition; if the amount is less than 5 parts by weight, there is a concern that the protective agent may set too quickly, and if it exceeds 10 parts by weight, there is a concern that strength performance may be reduced due to excessive hardening delay. Potassium monophosphate is preferably used in an amount of 25 to 35 parts by weight in the protective agent composition; if the amount is less than 25 parts by weight, although it is necessary for reaction with MgO, a decrease in the adhesion strength of the protective agent occurs due to insufficient phosphoric acid content, and if it exceeds 35 parts by weight, a problem of rapid setting occurs due to an excessive amount of phosphoric acid reaction.

[0021] Boric acid acts as a reaction inhibitor to suppress the rapid reaction of phosphates, and it is preferable to use 1 to 3 parts by weight in the protective agent composition. If the boric acid is less than 1 part by weight, a problem of reduced fluidity due to rapid setting of the protective agent occurs, and if it exceeds 3 parts by weight, poor curing of the protective agent film and flow problems on the coated surface before curing occur due to an excessive delay effect.

[0022] The protective agent composition described above is used by mixing it with water, and it can be advantageously applied as a protective coating agent for steel surfaces, particularly for protecting steel surfaces. In this case, it is preferable to use 15 to 25 parts by weight of water per 100 parts by weight of the protective agent composition; if the amount is less than 15 parts by weight, it is difficult to ensure the fluidity required for application, and if the amount exceeds 25 parts by weight, a problem arises where MgO in the protective agent settles due to the excessive amount of water mixed. When such a coating agent (a mixture of the protective agent and water) is applied to steel work platforms, effects such as securing corrosion prevention performance, ensuring walking safety by minimizing slippage, and improving wear resistance can be expected.

[0024] The present invention will be examined in detail below based on manufacturing examples and test examples. However, the following manufacturing examples and test examples are merely illustrative of the present invention and do not limit the scope of the present invention.

[0026] [Preparation Example] Preparation of porous MgO

[0027] Porous MgO was prepared by calcining weathered by prolonged exposure to moisture (ordinary MgO with characteristics of a fineness of 2,000–3,000 g / cm², an MgO content of 96% or more, and surface pores of 2 nm or less, in a state where reactivity is reduced due to reaction with atmospheric moisture after prolonged exposure to the atmosphere) at 1,200–1,300°C for more than 1 hour. In particular, during the calcination process, the furnace interior was instantaneously depressurized (depressurized by approximately 50–70 kPa gauge pressure) upon reaching a calcination temperature of 770–890°C. The porous MgO thus prepared had a fineness of 1,700–1,920 g / cm². 2 It exhibited characteristics of an MgO content of 96% or more and surface pores of 50 nm or more.

[0029] [Test Example] Characteristics of protective agent

[0030] 1. MgO-based phosphate ceramic protective agent

[0031] A porous MgO prepared according to [Preparation Example] was used, and an MgO-based phosphate ceramic protective agent was formulated as shown in [Table 1] below. To ensure the workability of the protective agent, the amount of water mixed was adjusted to be within the range of 20 ± 2 parts by weight per 100 parts by weight of the protective agent, so that workability could be achieved.

[0032] MgO-based phosphate ceramic protective agent formulation (parts by weight) division Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 General MgO 39.4 - - - - Porous MgO - 30 51 39.2 36.5 wollastonite 22 24 18 22 24 ammonium monophosphate 6.7 12.8 6.8 7.3 7 potassium monophosphate 30.2 31.4 22.8 30.2 30.9 boric acid 1.7 1.8 1.4 1.3 1.6 total 100 100 100 100 100 Mixed water quantity 19.2 19.8 21.2 20.5 20.5 # General MgO: Fineness 2,000~3,000 g / cm2, MgO content 96% or more, surface pores <2 nm # Porous MgO: Fineness 1,700~1,920 g / cm2, MgO content 96% or more, surface pores > 50 nm # Wollastonite: Particle size 1,000~2,000 µm, average length:diameter ratio 12:1 or greater # Ammonium Monophosphate: Specific gravity 1.8, apparent density (bulk density) 0.8~1.0 g / cm3, pH (1% solution) 4.3~5.0, 39 g / 100 ml water (25℃) # Potassium Monophosphate: K2HPO4, purity 98% or more, specific gravity 2.3, pH 8.7~9.3, SO4 content 2% or less, Loss on drying (100℃) 3% or less# Boric acid: Purity 98% or higher, Specific gravity 1.4±0.1, Solubility 49.6g / L (water at 20℃)

[0034] 2. MgO-based phosphate ceramic protective agent

[0035] To evaluate the characteristics of the MgO-based phosphate ceramic protective agent in [Table 1], surface hardness tests (KS M ISO 15184), adhesion tests (ASTM D 4541), slip resistance tests (KS F 2375, test method for slip resistance of road surfaces and curbs), and corrosion resistance tests (repeating the process of immersing the specimen in a 10% NaCl aqueous solution for 1 hour, removing it, and air-drying it at room temperature for 11 hours, and checking for corrosion occurrence up to the 10th day). The characteristic evaluation was performed after applying a single coating of 350–500 μm to a substrate surface (steel work platform) and curing at room temperature for 24–48 hours.

[0036] In addition, since ensuring safety for nighttime pedestrians is important for work platforms due to nighttime work, the residual area ratio of fluorescent paint was also evaluated to verify the safety effect of the walkway for nighttime pedestrians. The evaluation of the residual area ratio of fluorescent paint was conducted by applying fluorescent paint (generally using fluorescent paint products applied to walkways of buildings or structures for nighttime recognition) once after curing the protective agent, drying it at room temperature for 24 hours, and then comparing the relative residual area of ​​the fluorescent paint over the course of continuous pedestrian movement.

[0037] The results of the characteristic evaluation are shown in [Table 2] below.

[0038] Evaluation results of the characteristics of MgO-based phosphate ceramic protective agents division Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Surface hardness (H) 6 6 4 7 7 Adhesion (MPa) 1.99 1.33 1.74 2.48 2.65 Slip resistance (BPN) 42 53 32 79 83 Corrosion resistance (days elapsed since corrosion occurred) No corrosion Day 7 Day 6 No corrosion No corrosion Remaining fluorescent paint area percentage by walking duration (%) Day 5 74 79 56 89 93 Day 15 44 35 40 76 80 Day 30 26 32 31 74 77

[0039] As shown in [Table 2] above, it was confirmed that the surface hardness characteristics of Examples 1 and 2, which applied porous MgO and appropriately blended it with phosphate, were slightly improved compared to Comparative Examples 1 and 2. This is attributed to the fact that the curing characteristics were enhanced due to improved reactivity, as the surface area of ​​the porous MgO participating in the reaction with the phosphate component was increased. Adhesion was confirmed to be improved in Examples 1 and 2 compared to Comparative Examples 1 to 3, and this is also attributed to the improved reactivity resulting from the increased surface area of ​​the porous MgO. Slip resistance (BPN) also showed improved performance in Examples 1 and 2.

[0040] In the corrosion resistance evaluation, it was shown that no corrosion occurred in Examples 1 and 2 after 10 days of corrosion testing, just as in Comparative Example 1 where ordinary MgO was used. From this, it can be seen that using porous MgO does not affect the difference in corrosion performance.

[0041] In the evaluation of the residual area rate of the fluorescent paint, Comparative Example 1, which used ordinary MgO, showed a decrease in the residual rate of the fluorescent paint surface to 44% after 15 days, and Comparative Examples 2 and 3 also showed a significant decrease in the residual area rate of the fluorescent paint surface as the days of exposure to the external environment passed. In contrast, it was confirmed that the residual area rate of Examples 1 and 2 did not decrease significantly over time. These results are attributed to the fact that in the case of Examples 1 and 2, which used porous MgO with macropores, the fluorescent paint remained inside the pores of the porous MgO, and thus the fluorescent paint remained on the pore surface even when worn by pedestrians.

Claims

Claim 1 A magnesia protective agent composition having corrosion prevention and walking safety, characterized by comprising 30 to 45 parts by weight of porous MgO having macropores of 50 nm or more, 20 to 25 parts by weight of wollastonite, 5 to 10 parts by weight of ammonium monophosphate, 25 to 35 parts by weight of potassium monophosphate, and 1 to 3 parts by weight of boric acid. Claim 2 delete Claim 3 A magnesia protective agent composition having corrosion prevention and walking safety, wherein, in claim 1, the porous MgO is manufactured by calcining weathered MgO at 1,200 to 1,300°C, and undergoing a process of maintaining reduced pressure of 50 to 70 kPa when the calcination temperature reaches 770 to 890°C. Claim 4 A safety scaffold characterized by 15 to 25 parts by weight of water being mixed with 100 parts by weight of a magnesia protective agent composition according to claim 1 or 3, and the mixture being applied to a work scaffold to a thickness of 350 to 500 μm.

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