Antiviral composite resin composition with excellent virus inactivation function and composite resin coated steel sheet using the same

Abstract

The present invention contains 30 to 60% by weight of a urethane-modified polyester binder resin; 3 to 15% by weight of a curing agent; 0.1 to 10% by weight of a pigment; 0.1 to 10% by weight of an antiviral compound; and the balance solvent. The antiviral compound includes one or more selected from the group consisting of (A) metal hydroxides ([M1(OH)2]), (B) hydroxyapatite ([Ca 10 (PO4)6(OH)2]), and (C) thermosensitive titanium dioxide photocatalyst doped with metal ([M2-TiO2]). M1 is Ca or Mg, and M2 is Pt, Cr, V, Mn, Fe, Zn, Cu, Ni, Zr, Mo, Ag, W, or Au. The present invention provides an antiviral composite resin composition.

Description

Technical Field

[0001] The present invention relates to a composite resin composition having antiviral properties capable of killing viruses such as corona virus, and further to a composite resin-coated steel sheet having excellent virus-killing function using this composition.

Background Art

[0002] Recently, due to the worldwide pandemic of the coronavirus (Covid-19), not only are social-economic problems serious, but the development of vaccines and therapeutic agents is an urgent situation. The coronavirus that has been pandemic around the world recently has evolved from the SARS in 2013, the MERS in 2016, and the Covid-19 virus in 2019. Also, Covid-19 has mutated from alpha, beta, gamma, delta to the recently pandemic omicron, having a fatal impact on human health and wellness. The coronavirus contains RNA nucleic acid in an outer shell composed of spherical lipids and proteins. Most viruses penetrate into human or animal host cells and use the ribosomes of the host cells to replicate nucleic acids in large quantities and grow. Viruses are smaller in size compared to bacteria and fungi, can spread and replicate in a short time, mutate rapidly, and have a large transmission power, making it difficult to develop therapeutic agents and vaccines.

[0003] On the other hand, copper metal surfaces, nanometals or metal ions, and quaternary ammonium ions have been reported to have virus-killing properties. Copper metal is reported to kill bacteria or viruses by allowing nanometals leached from the surface to penetrate the outer layer of the bacteria or virus, causing them to lose their replication function. Metal ions such as Ag, Ni, and Zn are also reported to kill viruses through a similar mechanism. Polymers containing quaternary ammonium are reported to kill viruses by their inherent hydrophobic functional groups binding to the outer layer of bacteria or viruses, destroying their function. However, when using such metal ions in coatings, it is difficult to leach sufficient ions, or their effectiveness tends to decrease or disappear due to oxidation and discoloration during long-term use. Furthermore, the killing effect of organic compounds is limited not only because the effect is not complete when treating the surface of the material, but also because of the problem of toxicity to humans.

[0004] Composite coated steel sheets, particularly those used in home appliances and building materials, are typically manufactured with coating thicknesses of several to tens of micrometers or more for long-term use exceeding 10 years. In the case of the aforementioned metals, when applying the liquid coating solution to the steel sheet, there is a high possibility that some of the solution will be present within the coating film depending on its density, which hinders its ability to exhibit surface functionality. Furthermore, like copper metals, there is a problem of surface color change due to oxidation during long-term use. In addition, while some effects are observed when using quaternary ammonium compounds, the immediate effect is insufficient and not complete, thus limiting its use.

[0005] As part of efforts to address the harmful environment caused by such viruses, there is a need to develop special surface treatment products that can impart inactivation capabilities against viruses, particularly coronaviruses, to the surface of steel plates, which are essential materials in our lives. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Korean Published Patent Gazette No. 10-2020-0047666 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] One objective of the present invention is to provide a coating composition that not only does not undergo a change in hue even after long-term use, but also uses an inorganic compound that has a lower density than metal particles and easily floats to the surface of the coating film, thereby solving the above problems and having the function of killing microorganisms on the surface of the coating film.

[0008] Another object of the present invention is to provide a coated steel sheet using a coating composition having the antiviral properties described above. [Means for solving the problem]

[0009] According to one embodiment of the present invention, the material comprises 30-60% by weight of a urethane-modified polyester binder resin; 3-15% by weight of a curing agent; 0.1-10% by weight of a pigment; 0.1-10% by weight of an antiviral compound; and the remainder being a solvent, wherein the antiviral compound is (A) metal hydroxide ([M1(OH)2]), (B) hydroxyapatite ([Ca 10 An antiviral composite resin composition is provided, comprising one or more selected from the group consisting of (PO4)6(OH)2) and (C) metal-doped heat-sensitive titanium dioxide photocatalyst ([M2-TiO2]), wherein M1 is Ca or Mg and M2 is Pt, Cr, V, Mn, Fe, Zn, Cu, Ni, Zr, Mo, Ag, W, or Au.

[0010] According to another embodiment of the present invention, an antiviral composite resin coated steel sheet is provided, comprising a base steel sheet and an antiviral composite resin coating film containing an antiviral composite resin composition on at least one surface of the base steel sheet. [Effects of the Invention]

[0011] The present invention provides an antiviral composite resin composition, which is a polymer resin composition in which an inorganic oxide having the function of killing viruses and a heat-sensitive photocatalyst are dispersed. A coating film formed with the above-described composition of the present invention has the function of effectively killing viruses adsorbed on the coating film surface in the form of droplets, i.e., water containing viruses, by hydroxide anions and reactive oxygen species generated in the coating film. In particular, due to the complementary effect of the strong cation and anion elution properties of the inorganic hydroxide and the heat-sensitive photocatalyst that is activated by infrared rays even in the absence of light, the adsorption of virus-containing droplets is easy, and the killing of viruses is easy. In addition, there is the advantage that the properties of the antiviral substance do not change significantly even when steel plates for building materials are used for a long period of time. [Brief explanation of the drawing]

[0012] [Figure 1] This diagram schematically shows a cross-section of the antiviral composite resin coated steel sheet provided by the present invention and the principle of virus killing by the above antiviral composite resin coated steel sheet. [Modes for carrying out the invention]

[0013] Preferred embodiments of the present invention will be described below with reference to the attached drawings. However, embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0014] According to one embodiment of the present invention, a composite resin composition is provided in which a transparent resin composition comprising a urethane-modified polyester polymer resin, a curing agent, and a solvent contains a predetermined pigment and an antiviral substance. A coating film coated with such a resin composition of the present invention can form a coating film with excellent antiviral properties because the antiviral substance with a low specific gravity floats to the interface during curing.

[0015] The antiviral composite resin composition according to an embodiment of the present invention can provide a coating film excellent in processability and chemical resistance, and by forming a urethane-modified polyester resin coating film in which a pigment and an antiviral compound are mixed, each of the above components can form a composite network structure to provide excellent press processability and surface functionality.

[0016] For this purpose, the antiviral composite resin composition according to an embodiment of the present invention can contain 30 to 60% by weight of a urethane-modified polyester resin; 3 to 15% by weight of a curing agent; 0.1 to 10% by weight of a pigment; 0.1 to 10% by weight of an antiviral compound; and the balance as a solvent, based on the total weight of the resin composition.

[0017] For example, the antiviral composite resin composition according to an embodiment of the present invention can contain 40 to 60% by weight of a urethane-modified polyester resin; 5 to 15% by weight of a curing agent; 5 to 8% by weight of a pigment; 1 to 8% by weight of an antiviral compound; and the balance as a solvent, based on the total weight of the resin composition.

[0018] Hereinafter, each component of the resin composition of the present invention will be described in more detail.

[0019] <Binder Resin> The antiviral composite resin composition according to an embodiment of the present invention can use a urethane-modified polyester resin as the binder resin of the coating film. The urethane-modified polyester resin is excellent in the processability and chemical resistance of the coating film during curing.

[0020] The above urethane-modified polyester resin can have a weight average molecular weight (MW) of 2,000 to 30,000.

[0021] Preferably, the above urethane-modified polyester resin can have a weight average molecular weight (MW) of 5,000 to 25,000.

[0022] If the molecular weight of the urethane-modified polyester resin is less than 2000, the chemical resistance and processability of the coating film will be insufficient. If the molecular weight of the urethane-modified polyester resin exceeds 30000, the storage stability and workability of the solution may deteriorate. The urethane-modified polyester resin used may have a glass transition temperature of 0 to 70°C.

[0023] Furthermore, the urethane-modified polyester resin can preferably have a hydroxyl value of 10 to 300, more preferably 20 to 200.

[0024] If the hydroxyl value of the above-mentioned urethane-modified polyester resin exceeds 300, the chemical resistance of the coating film may decrease, and if the hydroxyl value of the above-mentioned urethane-modified polyester resin is less than 10, the cross-linking bonding properties of the coating film may decrease.

[0025] Furthermore, the above urethane-modified polyester resin can have an acid value of 5 to 30 mg KOH / g, preferably 10 to 25 mg KOH / g. mgKOH / g If this is exceeded, the chemical resistance of the coating film may decrease, and the above urethane-modified polyester resin 5 mg KOH / g If the value is below a certain level, the cross-linking properties of the coating film may decrease.

[0026] The content of the urethane-modified polyester resin can be 30 to 60% by weight of the entire antiviral composite resin composition, and more preferably 40 to 60% by weight. If it falls outside this range, drying properties may decrease during coating curing, and other physical properties may deteriorate.

[0027] <Hardening agent> In the antiviral composite resin composition according to one embodiment of the present invention, one or more curing agents selected from the group consisting of aziridine curing agents, melamine curing agents, and isocyanate curing agents may be used for curing the binder resin.

[0028] The above-mentioned curing agent is highly reactive and is not particularly limited; for example, an aziridine curing agent of the following structural formula (a) can be used. [ka] In the above structural formula (a), R can be -H, -CH3, -CH2CH3, -CH2CH2CH3, -CH2OH, or -CH2CH2OH, and the above aziridine curing agent can be used alone or in mixture of two or more types.

[0029] Furthermore, the melamine-based curing agent of the present invention may use iminomelamine of the following structural formula (b) or methylated melamine of the following structural formula (c). [ka]

[0030] [ka]

[0031] On the other hand, the melamine curing agent may be one or more selected from the group consisting of iminomelamine of structural formula (b) and methylated melamine of structural formula (c), although it is not limited to the above.

[0032] Compared to methylated melamine, iminomelamine has a faster curing reaction rate, making it advantageous for rapid curing. Increasing its content can increase the degree of curing and potentially raise the hardness of the coating film. On the other hand, completely substituted methylated melamine has a slower curing rate, but it provides a smoother coating film and offers superior surface quality.

[0033] Therefore, the antiviral composite resin composition according to one embodiment of the present invention can improve the surface quality of the coating film by using methylated melamine as a curing agent, while improving the reaction rate by adding iminomelamine, which has a fast reaction rate. Preferably, the iminomelamine of structural formula (b) and the methylated melamine of structural formula (c) can be mixed and used in a weight ratio of 1:1 to 1:4.

[0034] Furthermore, the isocyanate curing agent of the present invention can be an isocyanate curing agent such as monoisocyanate of the following structural formula (d) or diisocyanate of the following structural formula (e). [ka]

[0035] [ka]

[0036] As the isocyanate curing agent mentioned above, monoisocyanate of structural formula (d) or diisocyanate of structural formula (e) can be used.

[0037] In the above structural formula (d), R can be a methyl group, an ethyl group, a propyl group, a phenyl group, a 2-isopropylphenyl group, or a cyclohexyl group, among others.

[0038] In the above structural formula (e), R' is 1,3-phenylene, 1,4-phenylene, 2,4- Trile n(2,4- tolylen e) , 2,6- Trile n(2,6- tolylen e) m-xylylene, 4,4’- Dicyclohexylmeth n(4,4'- dicyclohexylmethan e) , 4,4’-Methylenediphen Ru (4,4'- methylenedipheny l) Examples include hexamethylene.

[0039] The isocyanate curing agents mentioned above can be used individually or in mixtures of two or more types.

[0040] The content of the curing agent can be 3 to 15% by weight of the entire antiviral composite resin composition, and more preferably 5 to 15% by weight. If the content of the curing agent is less than 3% by weight, insufficient curing may result in poor processability, and if it exceeds 15% by weight, over-curing may cause problems such as the coating easily cracking or crumbling.

[0041] <Pigments> An antiviral composite resin composition according to one embodiment of the present invention may contain a pigment having a specific hue. On the other hand, if the antiviral composite resin coated steel sheet according to another embodiment of the present invention further includes a primer coating, the primer coating may also contain a pigment.

[0042] The antiviral composite resin composition according to the present invention may have a unique hue consisting of a combination of black, red, and white pigments. The primer coating may, but is not limited to, a yellow or pale yellow pigment.

[0043] By mixing the above-mentioned black, red, yellow, and white pigments in predetermined proportions, a variety of hues can be achieved.

[0044] The content of the above pigment can be 0.1 to 10% by weight of the entire antiviral composite resin composition, and more preferably 5 to 8% by weight.

[0045] If the pigment content is less than 0.1% by weight, it is difficult to obtain high opacity and a beautiful hue for the steel plate. If it exceeds 10% by weight, the viscosity of the solution increases, reducing workability and making it difficult to obtain a beautiful surface appearance.

[0046] On the other hand, the primer coating can contain 1 to 8% by weight of pigment based on the total weight of the primer coating.

[0047] Examples of the black pigments mentioned above include carbon black, carbon nanotubes, graphite, and graphene, and may contain at least one selected from the group consisting of ferric oxide (Fe2O3), titanium dioxide (TiO2), carbon black, carbon nanotubes, graphite, and graphene. An example of a red pigment in this invention is ferric oxide (Fe2O3). Iron oxide has the advantages of being non-toxic, chemically stable, and capable of producing a variety of hues. An example of a white pigment in this invention is titanium dioxide (TiO2). An example of a yellow pigment in this invention is strontium chromate.

[0048] It is preferable to use a pigment with low oil absorption. The oil absorption of the pigment can be less than 60%, and preferably in the range of 5 to 50%.

[0049] Furthermore, the average particle size (particle size) of the above-mentioned colored pigment is preferably within the range of ±5 μm of the dry coating film thickness. For example, the average particle size (particle size) of the above-mentioned colored pigment can be in the range of 5 to 30 μm.

[0050] Furthermore, the antiviral composite resin composition according to one embodiment of the present invention may further contain, in addition to the above-mentioned colored pigment, a rust-preventive pigment for enhancing the rust-preventive properties of the coating film. As the rust-preventive pigment, one or more selected from the group consisting of colloidal silica, silica sol, and alkali metal silicate can be used.

[0051] <Antiviral compounds> An antiviral composite resin composition according to one embodiment of the present invention may contain an antiviral compound.

[0052] The above antiviral compounds include (A) metal hydroxide ([M1(OH)2]), where M1 is Ca or Mg, and (B) hydroxyapatite ([Ca 10 One or more selected from the group consisting of (C) metal-doped heat-sensitive titanium dioxide photocatalysts (represented by the formula [M2-TiO2], where M2 is Pt, Cr, V, Mn, Fe, Zn, Cu, Ni, Zr, Mo, Ag, W, or Au) can be used.

[0053] It is known that metal-doped titanium dioxide exhibits visible light or heat-sensitive photocatalytic properties according to the following principle. Generally, TiO2 photocatalysts require 3.1 eV of light energy. However, when the above TiO2 is doped with a special metal or metal oxide, photoactivation is possible in a lower energy range. An antiviral composite resin composition according to one embodiment of the present invention may contain heat-sensitive TiO2 that is photoactivated by visible light and infrared light using a metal oxide-doped TiO2 photocatalyst.

[0054] The above antiviral compound can be any one selected from the group consisting of (A) metal hydroxide, (B) hydroxyapatite, and (C) metal-doped heat-sensitive titanium dioxide photocatalyst.

[0055] Furthermore, as shown in Figure 1, the above antiviral compound may include a combination of two or more selected from the group consisting of (A) metal hydroxide, (B) hydroxyapatite, and (C) metal-doped heat-sensitive titanium dioxide photocatalyst.

[0056] For example, the above antiviral compound is one selected from the group consisting of (A) metal hydroxide and (B) hydroxyapatite. ;(C) A combination of metal-doped, heat-sensitive titanium dioxide photocatalysts can be used.

[0057] (C) Metal-doped heat-sensitive titanium dioxide photocatalysts generate radical species, and when combined with one selected from the group consisting of (A) metal hydroxides and (B) hydroxyapatite, they can exhibit even better antiviral performance.

[0058] The most effective antiviral properties can be observed when (A) metal hydroxide or (B) hydroxyapatite is used in a weight ratio of (C) metal-doped heat-sensitive titanium dioxide photocatalyst of 3:1 to 1:3.

[0059] Furthermore, the antiviral compound of the present invention may include all of the following: (A) metal hydroxide, (B) hydroxyapatite, and (C) metal-doped heat-sensitive titanium dioxide photocatalyst. When the weight ratio of the above (A) metal hydroxide, (B) hydroxyapatite, and (C) metal-doped heat-sensitive titanium dioxide photocatalyst is 1:1:1, the antiviral properties can be exhibited to be excellent, similar to those of the above embodiment.

[0060] The content of the above antiviral compound can be 0.1 to 10% by weight of the entire antiviral composite resin composition, and more preferably 1 to 8% by weight. If the content of the antiviral compound is less than 0.1% by weight, the virus killing rate may be low and the effect may be insufficient, and if it exceeds 10% by weight, the processability of the coating film may be poor.

[0061] <Remaining solvent> In an antiviral composite resin composition according to one embodiment of the present invention, the remainder of the components other than those blended above may be a solvent.

[0062] Furthermore, the primer coating composition for forming the primer coating film may also contain a residual solvent. The solvent contained in the above primer coating composition may be the same as or different from the solvent used in the antiviral composite resin composition.

[0063] The solvent may be, for example, one or more solvents selected from the group consisting of toluene, xylene, isopropanol, solvent naphtha, cellosolve, cellosolve acetate, and butyl cellosolve. The solvent may be one or a mixture of two or more solvents.

[0064] The viscosity of the composition can vary depending on the solvent content, but the solvent content added to each of the above compositions can be adjusted as needed and is therefore not particularly limited here. For example, in the case of the antiviral composite resin composition, the amount can be adjusted to a viscosity that requires 20 to 200 seconds to discharge from a DIN cup (DIN, 53211), taking into consideration the coating amount and adhesion, etc.

[0065] The antiviral composite resin composition according to one embodiment of the present invention may further contain, in addition to the above components, at least one additive such as wax, curing catalyst, pigment flocculation inhibitor, defoamer, or leveling agent, as needed, in order to further improve the physical properties of the coating film. Any of the above additives that are commonly used can be used in the present invention as appropriate and can be applied according to the usual mixing ratio.

[0066] The method for producing an antiviral composite resin composition according to one embodiment of the present invention is not particularly limited, but for example, a urethane-modified binder resin is used. Poly The resin composition can be manufactured by dispersing a curing agent in an ester resin, then further adding and dispersing pigments for hue and rust prevention, as well as an antiviral compound, before placing it in a solvent.

[0067] <Antiviral composite resin coated steel sheet> According to another embodiment of the present invention, an antiviral composite resin coated steel sheet is provided, comprising a coating film formed by the above-mentioned antiviral composite resin composition of the present invention. In describing the antiviral composite resin coated steel sheet, all of the above-mentioned descriptions of the antiviral composite resin composition can be applied in the same manner.

[0068] The above-mentioned antiviral composite resin coated steel sheet can be provided by applying the above-mentioned antiviral composite resin composition to at least one of the two surfaces (first surface and second surface) of the base steel sheet.

[0069] As the base steel sheet mentioned above, galvanized steel sheet can be used. Examples of galvanized steel sheets are not limited to those listed above, but include hot-dip galvanized steel sheet (GI), alloyed hot-dip galvanized steel sheet (GA), electro-galvanized steel sheet (EG), aluminum-plated steel sheet, or zinc-aluminum-magnesium ternary alloy-plated steel sheet.

[0070] The antiviral composite resin coating on the base steel sheet is formed by the provided antiviral composite resin composition, which may include a urethane-modified polyester resin, a melamine curing agent, a pigment, and an antiviral compound as described above.

[0071] The composition of the above-mentioned antiviral composite resin coating can be manufactured using a composition comprising 30-60% by weight of urethane-modified polyester resin, 3-15% by weight of curing agent, 0.1-10% by weight of pigment, 0.1-10% by weight of antiviral compound, and the remainder being a solvent, as described above.

[0072] For example, the antiviral composite resin composition provided for manufacturing the antiviral composite resin coated steel sheet of the present invention may contain 40-60% by weight of urethane-modified polyester resin; 5-15% by weight of curing agent; 5-8% by weight of pigment; 1-8% by weight of antiviral compound; and the remainder being a solvent, based on the total weight of the resin composition.

[0073] The above antiviral composite resin composition can be applied to a base steel sheet and then dried to form an antiviral composite resin coating. The application method and drying method are not particularly limited and can be any method commonly known in this art. Drying can be carried out by, but is not limited to, hot air heating, infrared heating, induction heating, or natural drying, for example.

[0074] More specifically, the antiviral composite resin composition according to one embodiment of the present invention is preferably dried at a Peak Metal Temperature (PMT) of 180 to 260°C. However, it is not limited thereto, but specifically, for example, in the case of a hot air heating method, the above composition can be dried by hot air treatment at an ambient temperature of 200 to 340°C for 10 to 50 seconds.

[0075] The above-mentioned antiviral composite resin coating can be formed to have a dry film thickness of 3 to 40 μm, preferably 5 to 30 μm.

[0076] If the dry film thickness of the above-mentioned antiviral composite resin coating is less than 5 μm, the hue, opacity, processability, and solvent resistance of the composite resin coating may decrease. If the dry film thickness of the above-mentioned antiviral composite resin coating exceeds 30 μm, it is undesirable because it increases manufacturing costs and reduces productivity.

[0077] <Primer coating> An antiviral composite resin coated steel sheet according to another embodiment of the present invention may be an antiviral composite resin coated steel sheet in which a primer coating is formed on at least one or both surfaces, and an antiviral composite resin coating provided as one embodiment of the present invention is formed on one of the primer coatings.

[0078] In the case of a steel sheet containing the above-mentioned antiviral composite resin coating (topcoat), the primer coating can be positioned as an undercoat between the base steel sheet and the antiviral composite resin coating (topcoat).

[0079] In the antiviral composite resin coated steel sheet according to another embodiment of the present invention, the primer coating film further formed on the first and / or second surface of the base steel sheet is not particularly limited. It may be any coating film known in the art to be applicable between the base steel sheet and the antiviral composite resin coating film (topcoat) in order to increase the adhesion between the base steel sheet and the antiviral composite resin coating film and to impart to the steel sheet other physical properties required for steel sheets, such as paintability and corrosion resistance.

[0080] For example, the primer coating composition for forming the above-mentioned primer coating film may be a composition comprising 40-60% by weight of polyethylene polymer resin, 5-15% by weight of melamine curing agent, 1-8% by weight of colloidal silica, and 1-8% by weight of pigment, with the remainder being a solvent. The remainder being a solvent may be different from or the same as the solvent used as the remainder solvent in the above-mentioned antiviral composite resin composition.

[0081] On the other hand, the primer coating can be applied so that the dry film thickness is 2 to 7 μm, preferably 3 to 5 μm. If the thickness of the primer coating exceeds 7 μm, manufacturing costs will increase and productivity may decrease, which is undesirable. If the thickness of the primer coating is 2 μm or less, it may become difficult to ensure the above quality characteristics.

[0082] The above-mentioned primer coating is a coating for concealing the material, preventing rust, and improving color, and is advantageous in terms of improving the color, concealment, processability, and corrosion resistance of the antiviral composite resin coating.

[0083] In another embodiment of the present invention, when the antiviral composite resin coating is formed on only one surface of the base steel plate, it is preferable to form the resin coating on the surface of the base steel plate where the composite resin coating is not formed, taking into consideration the processability and corrosion resistance of the steel plate. [Examples]

[0084] Examples The present invention will be described in more detail below through the examples provided. However, the following examples are merely illustrative of specific embodiments of the present invention and do not limit the present invention.

[0085] Examples 1-27 and Comparative Examples 1-9 A urethane-modified polyester resin, a curing agent, a pigment, an antiviral compound, and the remainder solvent were mixed in the proportions shown in Examples 1 to 27 and Comparative Examples 1 to 9 in [Table 1] below, and then dispersed using a high-speed bead mill disperser to produce an antiviral composite resin composition.

[0086] As the urethane-modified polyester resin mentioned above, a resin with a weight-average molecular weight of 16,000 to 20,000 (manufactured by KCC Co., Ltd., with a glass transition temperature (Tg) of 10 to 30°C) was used.

[0087] As the curing agents used, trimethylolpropane tris(β-N-aziridinyl)propionate was used as the aziridine-based curing agent, hexamethoxymethylmelamine as the melamine-based curing agent, and toluene diisocyanate as the isocyanate curing agent.

[0088] As for the above pigments, the black pigment is carbon black (Printex from Evonix). TM In this series, ferric oxide was used as the red pigment and titanium dioxide as the white pigment.

[0089] The above antiviral compounds were prepared by mixing (A) calcium hydroxide (Ca(OH)2) or (B) hydroxyapatite (Oszen Co., Ltd.) with (C) a metal-doped heat-sensitive titanium dioxide photocatalyst in a ratio of 3:1 to 1:3. In Examples 25 to 27, which contained all of (A):(B):(C), the mixture was prepared so that the weight ratio of each component was 1:1:1.

[0090] The remaining solvent used was cellosolve acetate.

[0091] In this case, (C) the metal-doped heat-sensitive titanium dioxide photocatalyst contains titanium compound [Ti(i-OC3H7)4], isopropyl alcohol, nitric acid, manganese compound [Mn(NO3)2)], platinum compound [Pt(NH3)2], and methyl tertiary. Toxi Silane (Methyltertiarymeth oxys ilane , MTMS It was manufactured using ).

[0092] More specifically, 5 L of distilled water was placed in a reactor, 100 ml of nitric acid and 220 g of Mn(NO3) were dissolved in it, and after heating to 80°C, 12.5 g of platinum compound [Pt(NH3)2] was added and stirred. In another reactor, 1500 g of titanium compound [Ti(i-OC3H7)4] and 150 ml of isopropyl alcohol were mixed and then added to the above solution. After the mixed solution was cooled to room temperature, methyl tertiary methyl Toxi Silane (Methyltertiarymeth oxys ilane , MTMS ) 10g was added, the resulting precipitate was filtered, and then dried at a temperature of 300°C to produce the product.

[0093] [Table 1]

[0094] The solution produced above yielded a single-sided plating deposition of 60 g / m², as shown in [Table 2]. 2 The antiviral composite resin composition of the above example was roll-coated onto a Zn-Al-Mg ternary alloy plated steel sheet or an alloy plated steel sheet having a primer coating layer to a dry coating thickness of 15-20 μm. After curing and drying at a peak metal temperature (PMT) of 232°C, it was cooled to produce antiviral composite resin coated steel sheets having composite resin coating layers as the example and comparative example.

[0095] The above primer coating layer was formed by drying a composition consisting of 50% by weight of polyethylene polymer resin, 10% by weight of melamine curing agent, 5% by weight of colloidal silica, 5% by weight of a pale yellow pigment, and the remainder being a solvent, so that the dry coating thickness was 5 μm.

[0096] The surface properties of the composite resin coated steel sheet having the composite resin coating layer obtained by the above manufacturing process were evaluated, and the results are shown in [Table 2] and [Table 3].

[0097] [Table 2]

[0098] [Table 3]

[0099] The surface properties and their evaluations shown in [Table 2] and [Table 3] above were performed using the following method.

[0100] <Coating film thickness> The coating thickness was measured using a non-destructive portable coating thickness gauge.

[0101] <Exterior design> The paint film hue was evaluated by color difference values ​​compared to a standard test piece of beige hue and expressed as follows. [Evaluation Criteria] ◎: ΔE < 1.0 (Excellent), ○: 1.0 ≤ ΔE < 1.5 (Good), △: 1.5 ≤ ΔE < 2.5 (Poor), ×: 2.5 < ΔE (Very Poor)

[0102] <Glossy> The 60° specular reflectance was measured and evaluated using equipment from SHEEN Corporation.

[0103] <Pencil hardness> Using Mitsubishi pencils (HB to 4H), a 10cm line was drawn at a 45° angle with a load of 1000±10g, and the presence or absence of scratches was evaluated.

[0104] <Corrosion resistance evaluation> Corrosion resistance was evaluated using the Cyclic Corrosion Test (CCT). Salt spraying was performed for 5 hours under conditions of 95% relative humidity (concentration 5%, 35°C, 1 kg / cm³). 2 The following conditions were met: spray pressure was used, followed by drying at 30% relative humidity and 70°C for 2 hours, then treatment at 95% relative humidity and 50°C for 3 hours. This process was repeated 100 times, and the area of ​​white rust that formed on the surface of the steel plate was evaluated. [Evaluation Criteria] ◎: Corrosion area is 0%, ○: Corrosion area is 5% or less, △: Corrosion area is 5-30%, ×: Corrosion area is 30% or more

[0105] <Bending processability evaluation> For steel sheets coated with an antiviral composite resin, the surface of the steel sheet was placed in a vise and bent 180° under a pressure of 1 kgf, then tightened until it was flat (0T-bending). After attaching Scotch tape to the bent coating, the presence or absence of crack formation and coating peeling on the surface where the tape peeled off was evaluated when the coating was removed. [Evaluation Criteria] ◎: No cracks or peeling, ○: Fine cracks are visible, but there is no peeling of the paint film, △: Severe cracking, but no peeling of the paint film, ×: Paint film peels off along with cracks.

[0106] <Chemical resistance> The performance was determined by the number of strokes required to remove the coating when gauze soaked in methyl ethyl ketone (MEK) was rubbed back and forth with a force of 1 kgf under a 1 kg load. [Evaluation Criteria] ◎: 100 times or more, ○: 70 times or more but less than 100 times, △: 40 times or more but less than 70 times, ×: less than 40 times

[0107] <Antiviral> <Short-term antiviral activity evaluation> The antiviral activity of the composite resin-coated steel sheets of the examples and comparative examples was evaluated according to ISO 21702 standards at the Institute of Zoonosis Control, Jeonbuk National University. COVID-19 (3.2 × 10⁶) cultured in monkey cells (Vero E6) was also evaluated. 6400 μL of the TCID50 / ml virus stock solution was dropped onto the control group and a composite resin-coated steel plate test piece (50 × 50 mm), covered with a polymer film (40 × 40 mm, polyethylene film), and left in contact at room temperature for 2 hours. After that, the samples were collected in 1.9 mL of culture medium. -1 ~10 -5 Serial dilutions were prepared until the desired result was reached. Each smear was used to infect monkey host cells (Vero E6 cells), which were then cultured at 37°C for 72 hours. After adding MTT stain (Triazolium) to each cultured well, the survival of the host cells was determined by observing the color change. The concentration value (TCID50) of the surviving cells in the wells was calculated and the viral mortality rate was quantitatively evaluated by comparing it with the control group.

[0108] <Long-term antiviral activity evaluation> The composite resin-coated steel sheet described above was irradiated for 1000 hours under QUV-B evaluation conditions, and its antiviral properties were evaluated using the same method as described in the short-term antiviral evaluation. [Evaluation Criteria] Virus mortality rate (X) is (◎): 95% ≤ X, (○): 90 ≤ X < 95%, (△): 80 ≤ X < 90%, (×): X < 80%

[0109] In the antiviral composite resin coated steel sheet of the present invention, the antiviral composite resin composition exhibits a beautiful hue and excellent aesthetic design when coated with a dry film thickness of 15 μm. However, it has been found that an even more beautiful hue is exhibited when a primer layer is included beneath the composite resin topcoat coating layer. This effect is judged to be due to the fact that as the film thickness increases due to the primer coating, the opacity of the base steel sheet increases, and the diffuse reflection of light decreases, resulting in increased clarity of the hue produced by the pigment.

[0110] In the antiviral composite resin coated steel sheet of the present invention, the antiviral composite resin composition is effective on its own as either (a) metal hydroxide or (b) hydroxyapatite, but when added together with (c) a metal-doped heat-sensitive titanium dioxide photocatalyst, the virus killing rate increased significantly. This result is judged to be because, when virus-containing droplets adhere to the coating surface of the steel sheet, the killing of the virus is promoted by the action of reactive oxygen species generated by the action of (c) the metal-doped heat-sensitive titanium dioxide photocatalyst, along with the cations and anions generated by (a) metal hydroxide or (b) hydroxyapatite. Furthermore, in the long-term durability evaluation of the antiviral composite resin coated steel sheet, excellent results were shown without any decrease in antiviral properties.

Claims

1. 30-60% by weight of urethane-modified polyester binder resin; Hardener: 3-15% by weight; Pigment 0.1 to 10% by weight; 0.1 to 10% by weight of an antiviral compound; and, The remaining solvent is included. The antiviral compound is (C) a metal-doped heat-sensitive titanium dioxide photocatalyst ([M2-TiO2]); and (A) Metal hydroxide ([M １ (OH) ２ ]) and (B) hydroxyapatite ([Ca １０ (PO ４ ) ６ (OH) ２ Includes one or more selected from the group consisting of ]) Said M １ It is Ca or Mg, Said M ２ The antiviral composite resin composition is Pt, Cr, V, Mn, Fe, Zn, Cu, Ni, Zr, Mo, Ag, W, or Au.

2. The antiviral composite resin composition according to claim 1, wherein the urethane-modified polyester binder resin has a weight-average molecular weight (MW) of 2,000 to 30,000.

3. The antiviral composite resin composition according to claim 1, wherein the urethane-modified polyester binder resin has a hydroxyl value of 10 to 300.

4. The antiviral composite resin composition according to claim 1, wherein the urethane-modified polyester binder resin has an acid value of 5 to 30 mgKOH / g.

5. The antiviral composite resin composition according to claim 1, wherein the curing agent is one or more selected from the group consisting of aziridine curing agents, melamine curing agents, and isocyanate curing agents.

6. The antiviral composite resin composition according to claim 5, wherein the isocyanate curing agent is one or more compounds selected from the group consisting of compounds represented by the following structural formulas (d) and (e). 【Chemistry 1】 (In the above structural formula (d), R is a methyl group, an ethyl group, a propyl group, a phenyl group, a 2-isopropylphenyl group, or a cyclohexyl group.) 【Chemistry 2】 (In the above structural formula (e), R' is 1,3-phenylene, 1,4-phenylene, 2,4-trylene, 2,6-trylene, m-xylylene, 4,4'-dicyclohexylmethane, 4,4'-methylenediphenyl, or hexamethylene.)

7. The pigment is at least one selected from the group consisting of ferric oxide (Fe ２ O ３ ), titanium dioxide (TiO ２ ), carbon black, carbon nanotubes, graphite, and graphene, and the antiviral composite resin composition according to claim 1.

8. The antiviral composite resin composition according to claim 1, wherein the pigment has an average particle size of 5 to 30 μm.

9. The antiviral composite resin composition according to claim 1, further comprising one or more rust-preventive pigments selected from the group consisting of colloidal silica, silica sol, and alkali metal silicate.

10. The antiviral composite resin composition according to claim 1, wherein the antiviral compound is a combination of (A) a metal hydroxide and (B) hydroxyapatite and (C) a metal-doped heat-sensitive titanium dioxide photocatalyst.

11. The antiviral composite resin composition according to claim 10, wherein the weight ratio of the antiviral compound to (A) metal hydroxide and (B) hydroxyapatite and (C) metal-doped heat-sensitive titanium dioxide photocatalyst is 3:1 to 1:

3.

12. The antiviral composite resin composition according to claim 1, wherein the antiviral compound comprises all of the above: (A) metal hydroxide, (B) hydroxyapatite, and (C) metal-doped heat-sensitive titanium dioxide photocatalyst.

13. The antiviral composite resin composition according to claim 12, wherein the weight ratio of (A) metal hydroxide, (B) hydroxyapatite, and (C) metal-doped heat-sensitive titanium dioxide photocatalyst is 1:1:

1.

14. The antiviral composite resin composition according to claim 1, wherein the remaining solvent is one or more selected from the group consisting of toluene, xylene, isopropanol, solvent naphtha, cellosolve, cellosolve acetate, and butyl cellosolve.

15. Raw steel sheet; and An antiviral composite resin coated steel sheet, wherein at least one surface of the base steel sheet includes an antiviral composite resin coating film containing the antiviral composite resin composition described in any one of claims 1 to 14.

16. The antiviral composite resin coated steel sheet according to claim 15, wherein the base steel sheet is a hot-dip galvanized steel sheet (GI), an alloyed hot-dip galvanized steel sheet (GA), an electro-galvanized steel sheet (EG), an aluminum-plated steel sheet, or a zinc-aluminum-magnesium ternary alloy-plated steel sheet.

17. The antiviral composite resin coated steel sheet according to claim 15, wherein the antiviral composite resin coating film has a dry film thickness of 3 to 40 μm.

18. The aforementioned base steel plate and the antiviral composite resin coating further include a primer coating, The antiviral composite resin coated steel sheet according to claim 15, wherein the primer coating is manufactured using a composition comprising 40 to 60% by weight of polyethylene polymer resin, 5 to 15% by weight of melamine curing agent, 1 to 8% by weight of colloidal silica, and 1 to 8% by weight of pigment, with the remainder being a solvent.

19. The antiviral composite resin coated steel sheet according to claim 18, wherein the primer coating has a dry coating thickness of 2 to 7 μm.

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