Aqueous heat insulation coating material

Abstract

To provide an aqueous heat insulation coating material which contains an aqueous resin, a film-forming auxiliary and a heat insulation agent.SOLUTION: An aqueous resin is at least one selected from the group consisting of an acrylic resin, a polyurethane resin and an epoxy resin. A lowest film-forming temperature of the aqueous resin is 5°C or higher. The film-forming auxiliary is at least one selected from the group consisting of a plasticizer, an alcohol ether-based solvent, an alcohol ester-based solvent, a mixed solvent of ethylene glycol monobutyl ether and dipropylene glycol butyl ether, and an aprotic solvent. The heat insulation agent is hydrated silica.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a paint, and in particular to a water-based heat insulating paint. [Background technology]

[0002] In the past, most of the paints used in painting conventional color steel sheets and automobiles were solvent-based paints, which were baked and dried at high temperatures. However, during the baking process at high temperatures, solvent-based paints often volatilize excessively, causing environmental pollution problems.

[0003] In conventional technology, water-based paints are sometimes used to improve the problem of excessive solvent evaporation in the painting of color steel sheets and automobiles. However, conventional water-based paints form a film quickly when formed at high temperatures (e.g., 250°C). As a result, problems such as pinholes, bubbling, cracks, and poor adhesion often occur on the coating surface. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to provide an improved water-based heat-insulating paint to match the equipment of conventional color steel plants. The improved water-based heat-insulating paint can be used as a replacement for conventional solvent-based paints without changing the existing manufacturing process and conditions, and effectively improves the problem of excessive solvent evaporation. Furthermore, the water-based heat-insulating paint of the present invention has excellent heat-insulating properties, which can achieve energy saving and carbon reduction effects. [Means for solving the problem]

[0005] In order to solve the above technical problems, one technical means adopted by the present invention provides an aqueous heat insulating paint containing an aqueous resin, a film forming aid, and a heat insulating agent which is hydrated silica. The aqueous resin is at least one selected from the group consisting of acrylic resin, polyurethane resin, and epoxy resin, and the minimum film forming temperature of the aqueous resin is 5°C or higher. The film forming aid is at least one selected from the group consisting of plasticizers, alcohol ether solvents, alcohol ester solvents, mixed solvents of ethylene glycol monobutyl ether and dipropylene glycol butyl ether, and aprotic solvents.

[0006] Preferably, the aqueous resin is an aqueous resin composition formed by emulsion polymerization, the aqueous resin composition comprising water, a monomer mixture, and an emulsifier, the monomer mixture comprising a first monomer which is an acrylate monomer, a second monomer which is an alkyl group-containing methacrylate monomer, a third monomer which is a styrene-containing monomer, and a fourth monomer which is a carboxyl group-containing monomer.

[0007] Preferably, the weight ratio of water:the first monomer:the second monomer:the third monomer:the fourth monomer:the emulsifier is 110-150:20-50:5-30:15-40:10-35:1-5.

[0008] Preferably, the weight ratio of water:the first monomer:the second monomer:the third monomer:the fourth monomer:the emulsifier is 120-140:30-45:8-25:20-35:15-30:2-5.

[0009] Preferably, the minimum film-forming temperature of the aqueous resin is 25° C. or higher.

[0010] Preferably, the minimum film-forming temperature of the aqueous resin is 25°C to 45°C.

[0011] Preferably, the boiling point of the film-forming auxiliary is 200° C. to 400° C., and the film-forming auxiliary has the following volatilization rate (1) or volatilization rate (2): (1) the volatilization rate of butyl acetate is taken as 100, and the relative volatilization rate of the film-forming auxiliary is 0.005 to 5; and (2) the volatilization rate of the film-forming auxiliary at 100° C. is 0.1 to 1.0 g / 1000 cm. 2 / h.

[0012] Preferably, the hydrated silica is anionic particles produced by a sol-gel method, and the specific surface area of ​​the anionic particles is 30.1 m 2 / g~100m 2 / g.

[0013] Preferably, the water-based heat-insulating coating further comprises an inorganic powder, and the inorganic powder is at least one selected from the group consisting of titanium dioxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, calcium phosphate, calcium sulfate, aluminum oxide, zirconium dioxide, zinc oxide, talc powder, kaolin, muscovite, expanded perlite, and inorganic dyes.

[0014] Preferably, the total weight of the water-based insulating paint is 100 wt%, the content of the water-based resin is 55 wt% to 85 wt%, the content of the film-forming aid is 2 wt% to 20 wt%, and the content of the insulating agent is 1 wt% to 10 wt%. Effect of the Invention

[0015] The advantageous effect of the present invention is that the water-based heat-insulating paint of the present invention has the technical effect of reducing carbon emissions, can replace traditional solvent-based paints, and has heat-insulating function. In addition, the water-based heat-insulating paint of the present invention is particularly suitable for high-temperature drying processes. The present invention can be used as a replacement for traditional solvent-based paints by selecting the water-based resin and film-forming assistant, without changing the process equipment and process conditions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the embodiments of the present invention will be described in accordance with certain specific embodiments, and those skilled in the art can understand the advantages and effects of the present invention based on the contents disclosed in this specification. The present invention can be implemented or applied in other different specific embodiments, and various modifications and changes can be made to each detail in this specification based on different perspectives and applications without departing from the concept of the present invention. The technical contents of the present invention will be described in more detail based on the following embodiments, but the disclosed contents do not limit the protection scope of the present invention.

[0017] It should be understood that although terms such as "first," "second," and "third" may be used herein to describe various materials or parameters, these materials or parameters are not limited by these terms, but are primarily used to distinguish one material from another or one parameter from another.

[0018] [Water-based heat-insulating paint] An embodiment of the present invention provides a water-based heat insulating paint, which can be used as a replacement for conventional solvent-based paints without changing process equipment and process conditions. The water-based heat insulating paint includes a water-based resin, a film forming aid, a heat insulating agent, and inorganic powders.

[0019] <Water-based resin> The aqueous resin is at least one selected from the group consisting of an acrylic resin, a polyurethane resin, and an epoxy resin.

[0020] More specifically, the aqueous resin has a minimum film forming temperature (MFFT), which is 5°C or higher, preferably 25°C or higher, and particularly preferably 25°C to 45°C.

[0021] It should be noted that the minimum film-forming temperature (MFFT) according to the embodiment of the present invention is the lowest temperature at which the resin can be uniformly aggregated when applied to a substrate. In this embodiment, the minimum film-forming temperature is measured according to the ISO 2115 measurement method.

[0022] In one embodiment of the present invention, the aqueous resin is an acrylic resin, and the minimum film forming temperature (MFFT) of the aqueous resin can be adjusted by changing the monomer composition. For example, the aqueous resin is formed by emulsion polymerization of an aqueous resin composition. The aqueous resin composition includes water, a monomer mixture, and an emulsifier. The monomer mixture includes a first monomer, a second monomer, a third monomer, and a fourth monomer.

[0023] Here, the first monomer is an acrylate monomer, the second monomer is an alkyl-containing methacrylate monomer, the third monomer is a styrene-containing monomer, and the fourth monomer is a carboxyl-containing monomer.

[0024] In one embodiment, the first monomer is butyl acrylate (BA), the second monomer is methyl methacrylate (MMA), the third monomer is styrene monomer (SM), and the fourth monomer is methacrylic acid (MAA).

[0025] To further explain, the emulsifier is, for example, at least one selected from the group consisting of reactive emulsifiers, anionic emulsifiers, and cationic emulsifiers. Preferably, the emulsifier is a reactive emulsifier (e.g., SR-10), but the present invention is not limited thereto.

[0026] Regarding the amounts used, the ratio by weight of water:first monomer (acrylate monomer, e.g., BA):second monomer (alkyl group-containing methacrylate monomer, e.g., MMA):third monomer (styrene-containing monomer, e.g., SM):fourth monomer (carboxyl group-containing monomer, e.g., MAA):emulsifier may be, for example, 110-150 (water):20-50 (first monomer):5-30 (second monomer):15-40 (third monomer):10-35 (fourth monomer):1-5 (emulsifier). Preferably, the ratio by weight may be, for example, 120-140 (water):30-45 (first monomer):8-25 (second monomer):20-35 (third monomer):15-30 (fourth monomer):2-5 (emulsifier). Particularly preferably, the weight ratio is, for example, 125-135 (water):33-40 (first monomer):10-20 (second monomer):25-30 (third monomer):20-25 (fourth monomer):3-5 (emulsifier).

[0027] In the above-mentioned configuration, the minimum film-forming temperature of the aqueous resin is 5°C or higher, preferably 25°C or higher, and particularly preferably 25°C to 45°C.

[0028] It is particularly noteworthy that in the mixed monomers, the first monomer (acrylate monomer) is a monomer that provides the aqueous resin with a low glass transition temperature (low Tg), and can provide excellent adhesion to the finally formed resin coating film. The second monomer (methacrylate monomer) is a monomer that provides the aqueous resin with a high glass transition temperature (high Tg), and can improve the minimum film formation temperature of the aqueous resin. The third monomer (styrene-containing monomer) is a hydrophobic monomer that has a different polarity from water molecules, and can provide the resin coating film with excellent water resistance and scratch resistance.

[0029] The molecular chain of the fourth monomer (carboxyl group-containing monomer) has a negative charge when dissociated in an aqueous phase environment and can bind to the positive charge of an inorganic powder (e.g., TiO2), so that the inorganic powder is dispersed and firmly present in the resin coating film, resulting in a resin coating film that is excellent in scratch resistance and does not easily fall off. In addition, the molecular structure of the fourth monomer has a carboxyl group. The carboxyl group of the fourth monomer interacts with the aqueous resin crosslinking agent, causing the resin coating film to form a network structure, thereby improving the mechanical strength of the resin coating film.

[0030] It is also worth noting that by controlling the minimum film-forming temperature of the water-based resin within the above range, the water-based heat-insulating paint will not form too quickly in the high-temperature drying process. The moisture and additives in the water-based heat-insulating paint can escape even at high temperatures, which makes the surface of the resin coating smooth. This effectively improves problems such as pinholes, bubbles, cracks, and poor adhesion on the coating surface that are commonly seen in conventional technology.

[0031] <Film-forming assistant> The film-forming assistant can improve the film-forming properties of the water-based heat-insulating paint and prevent cracks and damage caused by drying of the water-based heat-insulating paint.

[0032] In one embodiment of the present invention, the film-forming auxiliary is at least one selected from the group consisting of a plasticizer, an alcohol ether solvent, an alcohol ester solvent, a mixed solvent of ethylene glycol monobutyl ether and dipropylene glycol butyl ether, and an aprotic solvent.

[0033] It is worth noting that the boiling point of the film-forming assistant is 200°C to 400°C, preferably 225°C to 375°C. In addition, the relative evaporation rate of the film-forming assistant is 0.005 to 5, preferably 0.01 to 3, with the evaporation rate of butyl acetate being taken as 100. Alternatively, the evaporation rate of the film-forming assistant at 100°C is 0.1g / 1000cm. 2 / h~1.0g / 1000cm 2 / h, 0.5g / 1000cm 2 / h~0.8g / 1000cm 2 It is preferable that the ratio is / h.

[0034] For example, the film-forming aid may be 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (product: TXIB (registered trademark)). 2,2,4-trimethyl-1,3-pentanediol diisobutyrate is a plasticizer, has a boiling point of 281°C, and has a volatilization rate of 0.674 (g / 1000 cm) at 100°C. 2 ) / h.

[0035] In one embodiment, the film-forming aid may be dioctyl terephthalate (DOTP), which is a plasticizer having a boiling point of 375° C. and a relative volatilization rate of 0.01, where the volatilization rate of butyl acetate is 100.

[0036] In one embodiment, the film-forming aid may be diethylene glycol monohexyl ether (DEGME), which is an alcohol ether solvent having a boiling point of 259°C and a relative volatilization rate of 1, where the volatilization rate of butyl acetate is 100.

[0037] In one embodiment, the film-forming aid may be triethylene glycol monobutyl ether (TEGME), which is an alcohol ether solvent having a boiling point of 275° C. and a relative volatilization rate of 0.06, where the volatilization rate of butyl acetate is 100.

[0038] In one embodiment, the film-forming aid may be Texanol® alcohol ester, which is an alcohol ester solvent having a boiling point of 254° C. and a relative evaporation rate of 0.2, where the evaporation rate of butyl acetate is 100.

[0039] In one embodiment, the deposition aid may be Optifilm® enhancer 300 (OE300). Optifilm® enhancer 300 has a boiling point of 281° C. and a relative volatilization rate of 0.04, where the volatilization rate of butyl acetate is 100.

[0040] In one embodiment, the film-forming aid may be 1,3-dimethyl-2-imidazolidinone (DMI), which is an aprotic solvent having a boiling point of 225° C. and a relative volatilization rate of 3, where the volatilization rate of butyl acetate is 100.

[0041] Alternatively, the film-forming aid may be at least one selected from the group consisting of Texanol (registered trademark) alcohol ester, ethylene glycol monobutyl ether (BCS), and bis(2-ethylhexyl) terephthalate (DEHT), as necessary.

[0042] It is worth noting that in a preferred embodiment of the present invention, the film-forming assistant may be, for example, a composite assistant using two or more assistants at the same time. As a specific example, the film-forming assistant may be, for example, a composite assistant using TXIB and DOTP at the same time, or a composite assistant using DEGME and OE300 at the same time. In addition, the volume ratio of the two types of solvents is, for example, 30-70:70-30, and preferably 40-60:60-40, but the present invention is not limited thereto.

[0043] It is also worth noting that the content of the film-forming assistant in the water-based heat-insulating paint is 2wt% to 20wt% in order to give the water-based heat-insulating paint an excellent film-forming effect. If the content of the film-forming assistant is less than 2wt%, the water-based heat-insulating paint cannot achieve the film-forming effect. If the content of the film-forming assistant exceeds 20wt%, the water-based heat-insulating paint easily splits or gels.

[0044] In addition, since the film-forming aid has a relatively high boiling point and a relatively low volatilization rate, the film-forming aid does not volatilize completely even in a high-temperature drying process and can escape even at high temperatures, making the surface of the resin coating smooth, thereby improving problems such as pinholes, bubbles, cracks, and poor adhesion on the coating surface that exist in the prior art.

[0045] <Thermal insulation> The heat insulating agent is silicon dioxide produced by a sol-gel method, and is preferably hydrated silica.

[0046] In one embodiment of the present invention, the sol-gel produced silicon dioxide is anionic particles. The specific surface area of ​​the anionic particles is 30.1 m 2 / g~100m 2 / g.

[0047] The anionic particles can be suspended in a sodium ion solution or an ammonium ion solution, and the pH value of the solution is preferably controlled to pH 9 to pH 10 so as to maintain the stability of the solution and the dispersibility of the particles.

[0048] According to the above-mentioned configuration, by introducing the heat insulating agent into the water-based heat insulating paint, the heat insulating property of the water-based heat insulating paint can be improved.

[0049] <Inorganic powder> The inorganic powders include titanium dioxide (TiO2), aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), calcium carbonate (CaCO3), calcium phosphate (Ca3(PO4)2), calcium sulfate (CaSO4), aluminum oxide (Al2O3), zirconium dioxide (ZrO2), zinc oxide (ZnO), talc powder (Mg3SiO4O 10(OH)2), kaolin (Al2Si2O5(OH)4), muscovite (MICA), expanded perlite, and other inorganic dyes.

[0050] In one embodiment of the present invention, the average particle size (D50) of the inorganic powder is 0.08 μm to 3 μm, and preferably 0.1 μm to 0.3 μm. If the particle size of the inorganic powder is too large, the inorganic powder cannot be uniformly dispersed by stirring. If the particle size of the inorganic powder is too small, the thixotropy is too high, which leads to non-uniform stirring.

[0051] <Content of each ingredient> The content of the water-based resin is 55 wt% to 85 wt%, preferably 60 wt% to 80 wt%, and particularly preferably 62 wt% to 75 wt%, based on a total weight of the water-based heat-insulating coating material being 100 wt%. The content of the film-forming aid is 2 wt% to 20 wt%, preferably 3 wt% to 15 wt%, and particularly preferably 5 wt% to 15 wt%, based on a total weight of the water-based heat-insulating coating material being 100 wt%.

[0052] The content of the heat insulating agent is 1 wt% to 10 wt%, preferably 2 wt% to 8 wt%, and particularly preferably 3 wt% to 6 wt%, based on a total weight of the water-based heat insulating paint of 100 wt%. The content of the inorganic powder is 5 wt% to 25 wt%, preferably 10 wt% to 20 wt%, and particularly preferably 13 wt% to 17 wt%, based on a total weight of the water-based heat insulating paint of 100 wt%.

[0053] The advantageous effect of the present invention is that the water-based heat-insulating paint of the present invention has the technical effect of reducing carbon emissions, and can be used as a replacement for traditional solvent-based paints and have heat-insulating functions. The water-based heat-insulating paint is particularly suitable for high-temperature drying processes (250°C). The embodiment of the present invention can be used as a replacement for traditional solvent-based paints by selecting the water-based resin and film-forming assistant, without changing the process equipment and process conditions.

[0054] [Experimental data and measurement results] The contents of the present invention will be described in detail with the following experimental data and measurement results, but these examples are for understanding the present invention and the present invention is not limited thereto. Here, Examples 1 to 3 are for proving the technical effects of the present invention, and Comparative Example 1 had poor measurement results. Here, first, based on Production Examples 1 to 3, aqueous resins with different minimum film-forming temperatures MFFT for each of Examples 1 to 3 were prepared.

[0055] <Manufacturing 1> Based on the formulation of aqueous resin example 1 shown in Table 1, 130 parts by weight of pure water, 40 parts by weight of butyl acrylate (BA), 10 parts by weight of methyl methacrylate (MMA), 30 parts by weight of styrene (SM), 20 parts by weight of methacrylic acid (MAA), and 4 parts by weight of an emulsifier (reactive emulsifier SR-10) were mixed uniformly in a mixer to form a pre-emulsion. The pre-emulsion was then introduced into a reaction tank to carry out an emulsification reaction, producing an aqueous resin with a minimum film-forming temperature MFFT of 25°C. The definition of the minimum film-forming temperature has been explained above, so it will not be explained here again.

[0056] <Production Example 2> Based on the formulation 2 shown in Table 1, 130 parts by weight of pure water, 35 parts by weight of butyl acrylate (BA), 20 parts by weight of methyl methacrylate (MMA), 25 parts by weight of styrene (SM), 20 parts by weight of methacrylic acid (MAA), and 4 parts by weight of an emulsifier (reactive emulsifier SR-10) were mixed uniformly in a mixer to form a pre-emulsion. The pre-emulsion was then introduced into a reaction tank to carry out an emulsification reaction, producing an aqueous resin with a minimum film-forming temperature MFFT of 30°C.

[0057] <Production Example 3> Based on the formulation 3 shown in Table 1, 130 parts by weight of pure water, 33 parts by weight of butyl acrylate (BA), 16 parts by weight of methyl methacrylate (MMA), 26 parts by weight of styrene (SM), 25 parts by weight of methacrylic acid (MAA), and 4 parts by weight of an emulsifier (reactive emulsifier SR-10) were uniformly mixed in a mixer to form a pre-emulsion.The pre-emulsion was then introduced into a reaction tank to carry out an emulsification reaction, producing an aqueous resin with a minimum film-forming temperature MFFT of 40°C.

[0058] [Table 1]

[0059] <Example 1> The aqueous resin used in Example 1 was the aqueous resin with a minimum film-forming temperature MFFT of 25°C produced in Production Example 1. In Example 1, an aqueous heat-insulating paint containing 72 wt% aqueous resin, 5 wt% film-forming assistant, 5 wt% heat-insulating agent, 17 wt% inorganic powder, and 1 wt% other assistants (dispersant, crosslinking agent) was produced based on Table 2. The aqueous heat-insulating paint was then applied to a composite sheet material of a 150 μm PET film and a steel plate with a coating rod having a diameter of 250 μm, and dried at room temperature for 24 hours to form an aqueous heat-insulating coating layer, after which the physical properties of each item were evaluated.

[0060] <Example 2> The aqueous resin used in Example 2 was the aqueous resin with a minimum film-forming temperature MFFT of 30°C produced in Production 2. In Example 2, an aqueous heat insulating paint containing 75 wt% aqueous resin, 8 wt% film-forming assistant, 3 wt% heat insulating agent, 13 wt% inorganic powder, and 1 wt% other assistants (dispersant, crosslinking agent) was produced based on Table 2. The aqueous heat insulating paint was then applied to a composite sheet material of PET film and steel plate by the above method, and the physical properties were evaluated after drying.

[0061] <Example 3> The aqueous resin used in Example 3 was an aqueous resin with a minimum film-forming temperature MFFT of 40°C produced in Aqueous Resin Example 3. In Example 3, an aqueous heat-insulating paint containing 62 wt% aqueous resin, 15 wt% film-forming assistant, 6 wt% heat-insulating agent, 16 wt% inorganic powder, and 1 wt% other assistants (dispersant, crosslinking agent) was produced based on Table 2. The aqueous heat-insulating paint was then applied to a composite sheet material of a PET film and a steel plate by the above-mentioned method, and the physical properties were evaluated after drying.

[0062] <Comparative Example 1> The aqueous resin used in Comparative Example 1 was a commercially available acrylic aqueous resin (P-60 manufactured by CHAN SIEH ENTERPRISES CO., LTD, MFFT is 0°C). In Comparative Example 1, an aqueous heat insulating paint was produced based on Table 2. The aqueous heat insulating paint was then applied to a composite sheet material of a PET film and a steel plate by the above-mentioned method, and after drying, the physical properties were evaluated.

[0063] The evaluation items and measurement methods for physical properties are as follows.

[0064] <Appearance of coating layer> After drying at room temperature for 24 hours, the appearance of the coating layer was observed to evaluate whether the appearance was smooth or not and whether any irregularities were generated.

[0065] <Appearance after drying at 280℃> According to the application of water-based heat insulating paint to industrial products, the water-based heat insulating paint was applied to a steel plate by high-temperature and high-speed coating on the production line, and the coating layer sample was dried at room temperature for 24 hours and then placed in an oven and dried at a high temperature of 280°C for 1 minute. After that, the sample was evaluated for its appearance, whether it was normal, and whether there were any abnormalities such as blisters, cracks, or falling off.

[0066] <Adiabatic temperature difference ℃> According to the standard method of JG / T 235-2014, the adiabatic temperature difference (°C) was measured for the coating layer samples treated at a high temperature of 280°C.

[0067] <200 g Drop Ball Test> Using a drop ball impact tester, a 200 g steel ball was freely dropped from a predetermined drop test height (e.g., 100 cm) onto a sample of the coating layer treated at the high temperature of 280 °C, and it was observed whether there was any peeling of the coating film.

[0068] <MEK Wipe 100 times> A gauze was wetted with MEK (methyl ethyl ketone), and a sample of the coating layer treated at the high temperature of 280 °C was wiped 100 times using a friction tester, and it was observed whether there was any peeling of the coating film.

[0069]

Table 2

[0070] [Examination of Measurement Results] According to the above-mentioned measurement results, even after the aqueous heat-insulating coating layers produced in Examples 1 to 3 were dried at a high temperature of 280 °C for 1 minute, the appearance of the surface of the coating layer was normal in all cases, and no abnormalities such as swelling, cracking, or peeling occurred. By performing a heat-insulating temperature difference test on the aqueous heat-insulating coating layer that had undergone high-temperature drying, a heat-insulating temperature difference of 8 °C to 10 °C was obtained. When a 200 g drop ball test was performed on the aqueous heat-insulating coating layer, the result was "coating layer is normal" in all cases, and no peeling of the coating layer occurred. When a test of wiping the aqueous heat-insulating coating layer 100 times with MEK was performed, the result was "coating layer is normal" in all cases, and no peeling of the coating layer occurred. That is, the aqueous heat-insulating coating layers produced in Examples 1 to 3 can be subjected to high-temperature drying and have excellent heat-insulating properties, impact resistance, and solvent resistance. This result proves that when using an aqueous resin having a specific minimum film-forming temperature range, the problem of appearance abnormalities during production by high-temperature drying can be effectively solved, and good physical properties can be maintained.

[0071] The aqueous thermal insulation coating layer produced in Comparative Example 1 had some bubbles on the surface of the coating layer after drying at 280°C for 1 minute, resulting in an abnormal appearance. An adiabatic temperature difference test was performed on the aqueous thermal insulation coating layer after high-temperature drying, resulting in an adiabatic temperature difference of 5°C, and the thermal insulation effect was worse than that of Examples 1 to 3. When the aqueous thermal insulation coating layer was subjected to a 200g drop ball test, the result was "the coating film fell off." When the aqueous thermal insulation coating layer was subjected to a MEK wipe test 100 times, the result was "the coating film fell off." In other words, the aqueous thermal insulation coating layer produced in Comparative Example 1 could not withstand high-temperature drying, and the physical properties were not ideal.

[0072] [Advantageous Effects of the Embodiments] The advantageous effects of the present invention are that the water-based heat-insulating paint of the present invention has the technical effect of reducing carbon emissions, can replace traditional solvent-based paints, and has heat-insulating functions.

[0073] In addition, the water-based heat insulating paint of the present invention is particularly suitable for high-temperature drying processes (250° C.). The present invention allows the use of water-based paints that are not suitable for high-temperature drying processes as a replacement for conventional solvent-based paints, provided that the process equipment and process conditions are not changed, by selecting the water-based resin and film-forming assistant.

[0074] The above disclosure is merely a preferred embodiment of the present invention, and the scope of the claims of the present invention is not limited thereto. Therefore, all equivalent technical modifications made by utilizing the specification and drawings of the present invention are included in the scope of the claims of the present invention.

Claims

1. A water-based heat-insulating paint comprising a water-based resin, a film-forming aid, and a heat-insulating agent which is hydrated silica, the aqueous resin is at least one selected from the group consisting of an acrylic resin, a polyurethane resin, and an epoxy resin, and the minimum film-forming temperature of the aqueous resin is 5° C. or higher; The water-based heat-insulating coating material is characterized in that the film-forming auxiliary is at least one selected from the group consisting of plasticizers, alcohol ether-based solvents, alcohol ester-based solvents, mixed solvents of ethylene glycol monobutyl ether and dipropylene glycol butyl ether, and aprotic solvents.

2. The aqueous resin is an aqueous resin composition formed by emulsion polymerization, The aqueous resin composition includes water, a monomer mixture, and an emulsifier, 2. The water-based heat insulating coating according to claim 1, wherein the mixed monomer comprises a first monomer which is an acrylate monomer, a second monomer which is an alkyl group-containing methacrylate monomer, a third monomer which is a styrene-containing monomer, and a fourth monomer which is a carboxyl group-containing monomer.

3. The water: the first monomer: the second monomer: the third monomer: the fourth monomer: the emulsifier (weight ratio) is 110-150: 20-50: 5-30: 15-40: 10-35: 1-5. The water-based heat-insulating paint according to claim 2.

4. The water: the first monomer: the second monomer: the third monomer: the fourth monomer: the emulsifier (weight ratio) is 120-140: 30-45: 8-25: 20-35: 15-30: 2-5. The water-based heat-insulating paint according to claim 3.

5. The water-based heat insulating paint according to claim 4, wherein the minimum film-forming temperature of the water-based resin is 25°C or higher.

6. The water-based heat insulating paint according to claim 5, wherein the minimum film-forming temperature of the water-based resin is 25°C to 45°C.

7. The boiling point of the film-forming auxiliary is 200° C. to 400° C., and the film-forming auxiliary has the following volatilization rate (1) or volatilization rate (2): (1) the relative volatilization rate of the film-forming aid is 0.005 to 5, with the volatilization rate of butyl acetate being 100; (2) The volatilization rate of the film-forming assistant at 100° C. is 0.1 to 1.0 g / 1000 cm 2 The water-based heat insulating coating according to claim 1, wherein the water-based heat insulating coating is 0.01 to 0.15 wt.

8. The hydrated silica is an anionic particle produced by a sol-gel method, and the specific surface area of ​​the anionic particle is 30.1 m 2 / g to 100m 2 The water-based heat insulating coating according to claim 1, wherein the viscosity of the coating is 1 / g.

9. The water-based heat insulating coating further comprises an inorganic powder, 2. The water-based heat-insulating coating material according to claim 1, wherein the inorganic powder is at least one selected from the group consisting of titanium dioxide, aluminum hydroxide, magnesium hydroxide, calcium carbonate, calcium phosphate, calcium sulfate, aluminum oxide, zirconium dioxide, zinc oxide, talc powder, kaolin, muscovite, expanded perlite, and other inorganic dyes.

10. The total weight of the water-based heat-insulating paint is 100 wt%, the content of the water-based resin is 55 wt% to 85 wt%, the content of the film-forming assistant is 2 wt% to 20 wt%, and the content of the heat-insulating agent is 1 wt% to 10 wt%. The water-based heat-insulating paint according to any one of claims 1 to 9.

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