A coating composition resistant to deep embossing and antibacterial / antiviral and its uses

Abstract

The present invention provides a deep embossing resistant and antibacterial / antiviral coil coating composition, the raw materials of which include by weight: 30-70 parts of polyester resin, 2-25 parts of curing agent, 0.1-30 parts of pigment, dye or colorant, 5-15 parts of solvent, 0.1-15 parts of antibacterial / antiviral intermediate, 0.1-2 parts of catalyst, and 0.01-10 parts of other auxiliary components. The coating formed by the coating composition has strong flexibility and surface strength, good ductility, and high adhesion with the primer. In particular, it has the requirements of deep embossing performance and shows strong solvent resistance test performance in embossing MEK and impact MEK. At the same time, the coating surface can effectively inhibit and kill bacteria and viruses. The coil coating composition can be directly applied to household appliance coils and building materials coatings.

Description

Technical Field

[0001] The present invention belongs to the technical field of coatings. More specifically, it relates to a deep embossing-resistant and antibacterial / antiviral coil coating composition for coils or substrates and its uses. Background Art

[0002] With the increasing saturation of the global application of color-coated plates, the competition of products has become increasingly fierce. In order to reduce costs and improve cost performance, some domestic color steel plants reduce the thickness of steel plates and use the form of embossing to increase the form thickness and strength of the steel plates, so as to achieve the purpose of reducing costs.

[0003] However, the embossing depth has a great influence on the surface coating of color steel plates. It not only requires the paint film to have high flexibility and good shear strength, and can ensure the integrity and ductility of the paint film under mechanical tensile deformation. At the same time, with the increase of the embossing depth, the concavo-convex feeling on the surface of the embossed plate increases, and the roughness increases accordingly. It is inevitable that the back paint and the top paint will rub against each other during the transportation of stacked plates, resulting in the phenomenon of coating peeling. Therefore, it is required that the paint film has a certain strength and strong adhesion. However, in the current industry, whether domestic or foreign, there is no mature product that can meet these properties required after deep embossing. Therefore, it is necessary to develop a new resin system to meet the market demand.

[0004] On the other hand, with the increasing requirements of people for health, environment and hygiene, the demand for the functionality of color steel coatings is also increasing.

[0005] On the one hand, the present invention aims at the deficiencies of existing coil topcoats in terms of deep embossing resistance, such as micro-cracking of the surface coating after deep processing of color-coated plates, poor MEK of embossed plates, and paint peeling during the transportation of stacked plates, and provides a deep embossing-resistant coating composition. On the other hand, it also provides a coating composition with antibacterial / antiviral effects at the same time. Summary of the Invention

[0006] The present invention provides a deep embossing-resistant and antibacterial / antiviral coating composition, which is used for coating coils or substrates with a primer.

[0007] The first object of the present invention is to provide a coating composition that can not only resist deep embossing but also has antibacterial / antiviral properties.

[0008] On the one hand, the coating formed by the coating composition has strong flexibility, surface strength and ductility, and at the same time has high adhesion to the primer. The coating formed by the coating composition can especially meet the requirements of deep embossing resistance performance and shows strong solvent resistance performance in terms of embossing MEK and impact MEK. The coating composition can be directly applied to the coating of household appliance coils and building material coils.

[0009] On the other hand, the surface of the coating formed by the coating composition can effectively inhibit and kill bacteria and viruses.

[0010] The second object of the present invention is to provide the use of the coating composition as described above in the production of a coating.

[0011] To achieve the above first object, the present invention provides a coating composition that is resistant to deep embossing and antibacterial / antiviral. Among them, its components are included by mass parts: 30-70 parts of polyester resin; 2-25 parts of curing agent; 0.1-30 parts of pigment, dye or colorant; 5-15 parts of solvent; 0.1-10 parts of antibacterial / antiviral intermediate; 0.1-2 parts of catalyst; 0.01-10 parts of auxiliary component.

[0012] Furthermore, for the coating composition of the present invention, its components are included by mass parts: 40-60 parts of polyester resin; 5-15 parts of curing agent; 0.1-20 parts of pigment, dye or colorant; 7-12 parts of solvent; 1.5-12 parts of antibacterial / antiviral intermediate; 0.5-1.5 parts of catalyst; 0.01-10 parts of auxiliary component.

[0013] According to an important aspect of the present invention, the polyester resin may be an unmodified polyester resin or a modified saturated polyester resin.

[0014] The polyester resin is a polyester resin with active functional groups at the end groups. The active functional group is a hydroxyl group, and it can also be an active functional group such as an epoxy group or a blocked isocyanate. The active functional group crosslinks and cures with curing agents such as the following amino resins to form a film.

[0015] Since saturated polyester resin has outstanding characteristics such as good adhesion, strong versatility, weather resistance, and flexibility when used in topcoats, the polyester resin is preferably a saturated polyester resin.

[0016] More preferably, the modified saturated polyester resin is a saturated polyester resin modified by epoxy resin or / and acrylic resin. According to the actual application situation, one of the polyester resins can be selected optionally, or they can be combined as needed to obtain the optimal technical effect.

[0017] Different from the polyester resin molecules in the coating compositions for coils or substrates in the prior art, the present invention introduces epoxy resin to improve the adhesion between the primer and the substrate; or, a continuous -C-C- backbone of acrylate can be introduced into the polymer main skeleton at the same time, which reduces the bridging of ester bonds. The introduced acrylate functional group increases the molecular polarity as a polymer side chain and enhances the "riveting" effect of the polymer, thereby further improving the adhesion and solvent resistance of the obtained product.

[0018] The modified saturated polyester resin described in the present invention can be commercially available. For example, resins of the Cyster 401 series and Cyster 402 series sourced from Nippon Paint Co., Ltd., or other similar saturated polyester resins that can be purchased on the market.

[0019] In addition, from another perspective, the acid value of the polyester resin described in the present invention is 1 - 10 mg KOH / g, the hydroxyl value is 10 - 80 mg KOH / g, the solid content is 45 - 75 wt%, and the molecular weight is 2000 - 7000; preferably, the acid value of the polyester resin is 3 - 8 mg KOH / g, the hydroxyl value is 20 - 60 mg KOH / g, the solid content is 55 - 65 wt%, and the molecular weight is 3000 - 6000.

[0020] Furthermore, the polyester resin provided by the present invention improves the toughness and crosslinking degree of the coating film after film formation through special functional monomers and micro - branched design at the molecular chain ends.

[0021] Furthermore, the curing agent described in the present invention is an amino resin.

[0022] Preferably, the amino resin is selected from at least one of melamine formaldehyde resin, methyl - etherified urea - formaldehyde resin, methyl - etherified melamine resin, butyl - etherified urea - formaldehyde resin, butyl - etherified melamine resin, and phenyl - substituted melamine formaldehyde resin.

[0023] Among them, when methyl - etherified melamine resin uses a flexible main resin, the cured film has high flexibility, excellent formulation stability, good abrasion resistance and interlayer adhesion. And butyl - etherified melamine resin is an efficient cross - linker for functional polymers containing hydroxyl, carboxyl and amide groups. The resin has strong hydrophobicity and a relatively fast curing speed when the degree of polymerization is relatively high, which can improve the film hardness and has high abrasion resistance. Therefore, more preferably, the amino resin is selected from methyl - etherified melamine resin and / or butyl - etherified melamine resin.

[0024] Furthermore, the "pigment" and similar terms used in the present invention generally refer to any substance that can impart color to the composition; thus, the "pigment" and similar terms include all colorants, such as pigments, dyes, including but not limited to those used in the paint industry and / or listed in the Dry Color Manufactures Association (DCMA), as well as special effect compositions.

[0025] The colorant can include, for example, finely divided solid powders that are insoluble but wettable under the use conditions. The colorant can be organic or inorganic and can be agglomerated or non - agglomerated.

[0026] Suitable pigments that can be used according to the present invention include, but are not limited to, inorganic metal oxides, organic compounds, metal flakes, mica pigments for achieving "metallic" effect colors, extenders, or fillers.

[0027] Suitable inorganic pigments include titanium dioxide, carbon black, iron oxides, and / or calcined mixed metal oxides. Extender or filler pigments include kaolin, talc, calcium carbonate, diatomaceous earth, synthetic calcium silicate, perlite, cellulose fibers, ground silica, calcined clay, microspheres, fumed silica, treated fumed silica, titanium dioxide, wet-ground mica, synthetic fibers, snobrite clay, bentonite, micronized mica, palygorskite, and / or aluminum trihydroxide. In addition, exfoliated or non-exfoliated aluminum and mica can be combined with or without other pigments. Any amount of pigment suitable for imparting the desired color can be used, and pigments suitable for use with the coating compositions described in the present invention are known to those skilled in the art and can vary depending on the desired coating color or appearance.

[0028] If pigments are used, preferably, based on the total weight of the coating composition, the amount of pigment present in the coating composition of the present invention is no more than 30 parts, more preferably no more than 25 parts, and even more preferably no more than 20 parts.

[0029] Examples of dyes include, but are not limited to, those solvent-based and / or water-based dyes, such as phthalocyanine (pthalo) green or blue, iron oxide, bismuth vanadate, anthraquinone, perylene, aluminum, and quinacridone.

[0030] If dyes are used, preferably, based on the total weight of the coating composition, the amount of dye present in the coating composition of the present invention is no more than 20 parts, more preferably no more than 10 parts, and even more preferably no more than 5 parts.

[0031] The colorant can be in the form of a dispersion, including but not limited to a nanoparticle dispersion.

[0032] The nanoparticle dispersion can include one or more colorants or colorant particles of highly dispersed nanoparticles that can produce the desired visible color and / or opacity and / or visual effect.

[0033] The nanoparticle dispersion can include colorants such as pigments or dyes with a particle size less than about 150 nm, such as less than 70 nm, or less than 30 nm.

[0034] The nanoparticles can be produced by milling the raw materials of organic or inorganic pigments with a grinding medium having a particle size less than 0.5 mm. The nanoparticle dispersion can also be prepared by methods such as crystallization, precipitation, vapor phase condensation, and chemical milling (i.e., partial dissolution).

[0035] To minimize the re-aggregation of nanoparticles in the coating, a dispersion of resin-coated nanoparticles can be used. The "dispersion of resin-coated nanoparticles" used herein refers to a continuous phase in which discrete "composite microparticles" are dispersed, and the "composite microparticles" comprise nanoparticles and a resin coated on the nanoparticles.

[0036] If a colorant is used, preferably, the amount of the colorant present in the coating composition of the present invention is not more than 20 parts, more preferably not more than 10 parts, and even more preferably not more than 5 parts.

[0037] Furthermore, the solvent is selected from at least one of cyclohexanone, propylene glycol methyl ether acetate, xylene, butyl acetate, solvent naphtha S-100, solvent naphtha S-150, DBE, and 2-butanone.

[0038] Another important aspect of the present invention is an antibacterial / antiviral intermediate. Preferably, the antibacterial / antiviral intermediate is 1.5 - 12 parts by weight based on the coating composition of the present invention.

[0039] Furthermore, to improve the fineness of the resulting coating composition, the fineness of the antibacterial / antiviral intermediate is less than 15 μm; preferably, the fineness of the antibacterial / antiviral intermediate is less than 10 μm; more preferably, the fineness of the antibacterial / antiviral intermediate is less than 5 μm.

[0040] The components of the antibacterial / antiviral intermediate at least include a polyester resin, a solvent, an antibacterial / antiviral agent, a dispersant, and a stabilizer.

[0041] Furthermore, the antibacterial / antiviral agent intermediate is mainly formulated from the following components by weight: 30 - 60 parts of polyester resin, 15 - 30 parts of solvent, 30 - 60 parts of antibacterial / antiviral agent, 0.1 - 1.2 parts of dispersant, and 0.2 - 0.8 parts of stabilizer.

[0042] Among them, the polyester resin can be the modified or unmodified polyester resin as described above, which will not be elaborated here. And the solvent can also be the solvent as described above. This will not be elaborated here either. The dispersant and stabilizer are well-known to those skilled in the art and are also mentioned below.

[0043] As an effective component in the antibacterial / antiviral intermediate, the antibacterial / antiviral agent or similar terms in the present invention generally refer to chemical substances that can keep the growth or reproduction of certain microorganisms (such as bacteria, fungi, yeasts, algae, and viruses) below the necessary level within a certain period of time. Therefore, the "antibacterial / antiviral agent" and similar terms include all bacteriostatic and fungicidal agents, such as mildew-proof agents and antibacterial agents, including but not limited to those used in industrial paints and coatings.

[0044] Furthermore, the antibacterial / antiviral agent comprises effective components of metal salts and their metal microparticles.

[0045] More preferably, the antibacterial / antiviral agent comprises particles of at least one of metal salts and their complex salts, oxides and their own nanoparticles having antibacterial / antiviral activity, such as silver, copper, iron, zinc, etc., with or without loading. Because of its high storage stability in air, it can meet the requirements of rapid high-temperature baking of the coating composition described in the present invention.

[0046] Furthermore, the carrier of this type of antibacterial / antiviral agent is selected from carriers that are easily dispersed in the medium and whose particles are not easily agglomerated, including but not limited to glass, zirconium phosphate, aluminum phosphate, calcium phosphate, zeolite, ceramic, activated carbon, long-acting biochar, etc.

[0047] Although the antiviral agent used in this embodiment may have any particle size appropriately determined by those skilled in the art, it is preferably provided in the form of fine particles with an average particle size of 15 μm or less.

[0048] Relative to the total solid component amount on the carrier, the antiviral agent contains 0.01 wt% to 10 wt% of the effective components of the metal salts and their metal microparticles, and more preferably 0.1 wt% to 5 wt% of the effective components.

[0049] The antibacterial / antiviral agent can be provided by multiple manufacturers on the current market. It includes, for example, antibacterial / antiviral agents produced by companies such as Noco Chemical, Fuji Chemical Industry of Japan, Corning, TRA Thomson Research Center, Polymore GreenTech Pte Ltd, etc. Specific models include NUCOCARE AGM, MP-102SVC615, BM-102SVP02, Guardiant, Ultra-Fresh, GA50, etc., as well as other similar antibacterial / antiviral agents that can be purchased on the market, and broad-spectrum metal oxides and their salts, such as zinc oxide. The antibacterial / antiviral agent described in the present invention has good antibacterial / antiviral activity. Based on what is known in the art, one of the antibacterial / antiviral agents can be optionally selected, or they can be combined in any ratio to obtain the optimal effect.

[0050] Because the antibacterial / antiviral agent described in the present invention does not require any pretreatment of antiviral components. In addition, when dispersed in a dispersion medium such as air and solvent, the antibacterial / antiviral agent is stable, so no special cleaning treatment is required. Therefore, the antibacterial / antiviral agent can easily exhibit and maintain its antiviral activity.

[0051] The antibacterial / antiviral agent of the present invention can be used in various forms. The antibacterial / antiviral agent of the present invention can be used in the form of, for example, powder, but it can also be used in any other suitable form. For example, the antibacterial / antiviral agent can be dispersed in a dispersion medium such as solvents like S150, ethyl acetate, etc. In addition, the antibacterial / antiviral agent provided by the present invention also has antibacterial and bacteriostatic effects, and the antibacterial / antiviral agent can be mixed with other antibacterial / antiviral agents, antimicrobial agents, mildew-proof agents, anti-allergy agents, catalysts, anti-reflection materials or heat-insulating materials.

[0052] The antibacterial / antiviral agent described in the present invention has broad-spectrum antibacterial properties and has good effects on common harmful microorganisms such as bacteria, molds, yeasts, algae, etc., and can also inhibit the reproduction of these bacteria on the material surface for a long time without generating drug resistance. Some of these antibacterial agents also have bactericidal and inhibitory effects on viruses.

[0053] Furthermore, the antibacterial / antiviral agent of the present invention can be used to inactivate an unlimited range of bacteria, regardless of their genomic type. Examples of these bacteria include, but are not limited to, Staphylococcus aureus (Gram-positive bacterium), Escherichia coli, Klebsiella (Gram-negative bacterium), Candida albicans, Pseudomonas aeruginosa, Staphylococcus epidermidis, Bacillus subtilis, Bacillus megaterium, Salmonella typhimurium, Methicillin-resistant Staphylococcus aureus (MRSA), Multidrug-resistant Streptococcus pneumoniae (MDRSP), Vancomycin-resistant Enterococcus (VRE), Multidrug-resistant Mycobacterium tuberculosis (MDR-TB), Multidrug-resistant Acinetobacter baumannii (MRAB), and Escherichia coli and Klebsiella pneumoniae carrying the NDM-1 gene, etc.

[0054] Furthermore, the antibacterial / antiviral agent of the present invention can be used to inactivate an unlimited range of molds, regardless of their genomic type. Examples of these molds include, but are not limited to, Aspergillus niger, Aspergillus flavus, Chaetomium globosum, Cladosporium herbarum, Paecilomyces variotii, Penicillium citrinum, Trichoderma viride, Aureobasidium pullulans.

[0055] Furthermore, the antiviral agent of the present invention can be used to inactivate an unlimited range of viruses, regardless of their genomic type and whether they are enveloped. Examples of such viruses include, but are not limited to, rhinovirus, poliovirus, rotavirus, norovirus, enterovirus, hepatovirus, astrovirus, sapovirus, hepatitis E virus, influenza A / B / C virus, parainfluenza virus, adenovirus, measles virus, human metapneumovirus, RSV, nipah virus, hendra virus, yellow fever virus, dengue virus, Japanese encephalitis virus, West Nile virus, hepatitis B / C virus, eastern and western equine encephalitis virus, o'nyong-nyong virus, rubella virus, Lassa virus, Junin virus, Machupo virus, Guanarito virus, Sabia virus, Crimean-Congo hemorrhagic fever virus, sandfly fever virus, hantavirus, Sin Nombre virus, rabies virus, Ebola virus, Marburg virus, bat lyssavirus, human T-cell leukemia virus, human immunodeficiency virus, human coronavirus, SARS coronavirus, human parvovirus, human polyomavirus, human papilloma virus, adenovirus, herpes virus, varicella virus, herpes zoster virus, Epstein-Barr virus, cytomegalovirus, smallpox virus, monkeypox virus, vaccinia virus, Molluscipoxvirus, and parapoxvirus.

[0056] Furthermore, stabilizers or similar terms used in the antibacterial agent intermediate of the present invention, such as suspending agents or anti-settling agents, etc., are known in the art and include organic and inorganic ones, preferably bentonite, fumed silica, microcrystalline calcium carbonate, cellulose and its derivatives; or at least one of polyolefin wax and phosphate-modified polyester resin.

[0057] Further, the present invention also includes a catalyst. The catalyst is preferably an acid catalyst, more preferably a blocked acid catalyst, and is selected from at least one of dinonylnaphthalene disulfonic acid (DNNDSA), dinonylnaphthalene sulfonic acid (DNNSA), dodecylbenzenesulfonic acid (DDBSA), and p-toluenesulfonic acid (P-TSA).

[0058] Further, the coating composition provided by the present invention further comprises other auxiliary components, which do not negatively affect the coating composition or the cured coating composition produced therefrom, and are generally used to enhance the aesthetics of the coating to facilitate the manufacture, processing, treatment, and coating of the composition, and further improve the specific functionality of the coating composition or the cured coating composition produced therefrom.

[0059] For example, the auxiliary components of the present invention optionally include a leveling agent, an antifoaming agent, a dispersant, an adhesion promoter, a matting powder, a wax substance, and mixtures thereof according to needs to provide desired film properties. Each optional component is preferably included in an amount sufficient for its intended purpose, but the amount does not negatively affect the coating composition or the cured coating composition produced therefrom.

[0060] The auxiliary component of the present invention further includes an adhesion promoter, which is selected from epoxy-based, silanol-based, and phosphate-modified polymers, preferably a phosphate-modified polymer, such as at least one of PAE 206, DS-600, Lubrizol 2063, AKN-6105, Tech-7205, ADP, SN7063, and TZ8805. Preferably, the adhesion promoter is in an amount of 0.1-2 parts by mass, more preferably 0.5-1.5 parts by mass, in the coating composition of the present invention.

[0061] A dispersant, a leveling agent, and an antifoaming agent can also be optionally added to the coating composition to help improve the appearance of the coating in terms of fluidity and wettability. Such components suitable for use with the composition of the present invention are known to those skilled in the art and can vary according to the desired appearance of the coating.

[0062] The dispersant is preferably at least one of BYK 110, BYK115, BYKP-104, and SOLSPERSE 2000.

[0063] The leveling agent is a non-silicon-based leveling agent, preferably at least one of BYK-392, BYK-054, BYK-355, BYK-358N, and AFCONA-3773 of BYK Chemie.

[0064] The antifoaming agent is a non-silicon-based antifoaming agent, preferably at least one of BYK-352, BYK-354, and AFCONA2720.

[0065] If such components are used, preferably, the dispersant, leveling agent, and defoaming agent contained in the coating composition of the present invention are each in an amount of 0.01 - 10 parts by mass, more preferably 0.1 - 5 parts by mass.

[0066] According to yet another aspect of the present invention, the above-described coating composition provided by the present invention can be used to produce a coating. The coating composition is typically applied to a primed coil or substrate, and the coating composition can be applied as a single layer, a double layer, or even multiple layers.

[0067] Suitable coils or substrates include, but are not limited to, coils or substrates formed from cold-rolled steel, ground steel, pickled steel, iron phosphate-treated steel, zinc phosphate-treated steel, hot-dip galvanized steel, zinc-aluminum-magnesium alloy, electro-galvanized steel sheet, tin-plated steel sheet, stainless steel, aluminum alloy, brass, etc.

[0068] In some embodiments, the specific coating process can apply the above-described coating composition as a topcoat to the primer to be treated through conventional coating techniques such as roll coating, spray coating, dip coating, etc.

[0069] After the coating composition is applied to the substrate, various processes can be used to cure the coating composition. For example, oven baking by conventional or convection methods, or any other method that provides a high temperature suitable for curing the coating.

[0070] The curing process can be carried out in separate or combined steps. The curing conditions will vary depending on the coating method and the intended end use.

[0071] The curing process can be carried out at any suitable temperature. The temperature includes, for example, an oven temperature in the range of about 100°C - 500°C, and more preferably about 200°C - 420°C.

[0072] The film thickness of the coating film formed by applying the coating composition will vary depending on the intended application, but is generally in the range of 10 - 25 μm in terms of dry film thickness, preferably 12 - 18 μm.

[0073] The baking process of this topcoat is usually baked in a 300°C oven for 40 - 60 s, and the metal plate temperature PMT: 216 - 249°C, preferably PMT 224 - 241°C.

[0074] The primer used in combination with the coating composition provided by the present invention can be a conventional primer coating known in the art, including but not limited to alkyd polyester primer, saturated polyester primer, polyurethane primer, epoxy primer, and other primers known to those skilled in the art.

[0075] The film thickness of the coating film formed by applying the primer will vary depending on the intended application and type. The dry film thickness of a single application of the primer layer is generally in the range of 5 - 15 μm, preferably 3 - 8 μm.

[0076] The baking process of the primer coating is usually carried out in an oven at 300 °C for 40 - 60 s, with the metal plate temperature PMT: 210 - 249 °C, preferably PMT 216 - 224 °C.

[0077] Furthermore, the embossing depth obtained from the coating composition is 10 - 100 μm, preferably 30 - 80 μm, and more preferably 50 - 70 μm.

[0078] According to another aspect of the present invention, there is also provided a method for preparing the coating composition as described above, which comprises the following steps:

[0079] (1) Mix the first polyester resin, solvent, antibacterial / antiviral agent, dispersant, and stabilizer in a certain proportion to obtain an antibacterial / antiviral intermediate;

[0080] (2) Pre - mix a part of the second polyester resin, a part of the solvent, pigments, and a part of the additives in a certain proportion and then grind them until the fineness is not greater than 10 μm, and filter to obtain a semi - finished product color paste;

[0081] (3) Disperse and mix evenly the remaining second polyester resin, the remaining solvent, curing agent, semi - finished product color paste, antibacterial / antiviral intermediate, catalyst, and additives. After mixing, the fineness of the mixture is less than 20 μm; preferably, the fineness of the mixture is less than 15 μm;

[0082] (4) Adjust the viscosity of the obtained product to a viscosity of 100 - 140 s for a coating - 4 cup, and the coating composition is obtained.

[0083] Furthermore, when the pigment used in step (2) is a special metallic or non - metallic flake pigment with a metallic texture, the grinding and filtering steps are not required in the preparation method, but a pre - soaking step is required to fully and evenly wet and disperse it in the solvent.

[0084] The pre - soaking step is as follows: Add the metallic or non - metallic flake pigment with a metallic texture to a part of the solvent in advance and soak it at room temperature for 1 - 3 hours to fully and evenly wet it and disperse it in the solvent to obtain a metallic color semi - finished product color paste.

[0085] The fineness of the above - mentioned metallic color semi - finished product color paste is preferably less than 20 μm; more preferably, its fineness is less than 15 μm for use in step (3).

[0086] The beneficial effects of the present invention are as follows:

[0087] On the one hand, the present invention overcomes the deficiencies of the existing coil topcoats in terms of deep embossing resistance. By introducing a new resin system into the coating composition, a modified polyester resin with high toughness and high adhesion is provided, thereby endowing the coating with excellent MEK bend resistance performance, improving the MEK resistance performance after embossing, and also enhancing the adhesion and solvent resistance performance of the coating.

[0088] On the other hand, the present invention also introduces an antibacterial / antiviral intermediate into the coating composition. The formed coating retains the original properties such as weather resistance while having a long-lasting antiviral / antibacterial effect, and the antibacterial / antiviral agent has no negative impact on the coating properties.

[0089] Meanwhile, the preparation method of the coating composition provided by the present invention is simple and does not require special equipment and processes. Detailed Embodiments

[0090] To make the technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments. Those skilled in the art should understand that the specific content described below is illustrative rather than restrictive, and should not be used to limit the protection scope of the present invention.

[0091] In the case of clarifying and explaining the object of the present invention through the following embodiments, the components of the coating composition are explained with weight parts as the general standard. Unless otherwise specified, for the sake of simplicity, the "parts" described in the embodiments of the present invention have the same meaning as weight parts.

[0092] The technical solutions of the present invention will be described below in conjunction with specific embodiments. Some of the raw materials and their related information used in the following embodiments are:

[0093] Polyester resin:

[0094] Cyster 40109: It is a modified saturated polyester resin produced by Nippon Paint Co., Ltd., with an acid value of 3 - 5 mg KOH / g, a hydroxyl value of 20 - 30 mg KOH / g, a solid content of 60 wt%, and a molecular weight of 3000 - 4000;

[0095] Cyster 40207: It is a modified saturated polyester resin produced by Nippon Paint Co., Ltd., with an acid value of 3 - 8 mg KOH / g, a hydroxyl value of 20 - 30 mg KOH / g, a solid content of 60 wt%, and a molecular weight of 5000 - 6000;

[0096] OF - 67: It is an unmodified saturated polyester resin produced by Nippon Paint Co., Ltd., with an acid value of 3 - 8 mg KOH / g, a hydroxyl value of 40 - 50 mg KOH / g, a solid content of 60 wt%, and a molecular weight of 3000 - 4000.

[0097] Amino resin:

[0098] YP5603: Hexamethoxymethyl melamine resin produced by Shanghai Yuanbang;

[0099] CYMEL 303: Hexamethoxymethyl melamine resin produced by Allnex;

[0100] CYMEL 325: A methyl etherified high imino melamine resin produced by Allnex.

[0101] Antibacterial / antiviral intermediates:

[0102] Antibacterial / antiviral intermediate 1: 30 parts of polyester resin Cyster 40109, 20 parts of solvent S150, 50 parts of antibacterial agent Guardiant, 0.5 parts of dispersant BYK 110, and 0.5 parts of stabilizer Benton 38.

[0103] Antibacterial / antiviral intermediate 2: 30 parts of polyester resin Cyster 40109, 20 parts of solvent S150, 50 parts of antibacterial BM-102SVP02, 0.5 parts of dispersant BYK 110, and 0.5 parts of stabilizer AEROSIL R972.

[0104] Antibacterial / antiviral intermediate 3: 30 parts of polyester resin Cyster 40207 (also produced by Nippon Paint), 20 parts of solvent S150, 25 parts of antibacterial agent BM-102SVP02, 25 parts of antibacterial agent GA50, 0.5 parts of dispersant BYK 110, and 0.5 parts of stabilizer Benton 38.

[0105] Antibacterial / antiviral intermediate 4: 30 parts of polyester resin Cyster 40207 (also produced by Nippon Paint), 15 parts of solvent S150, 50 parts of zinc oxide, 5 parts of antibacterial agent Guardiant, 0.5 parts of dispersant BYK 110, and 0.2 parts of stabilizer MPA1078X.

[0106] The polyester resin, solvent, antibacterial agent, dispersant and suspension stabilizer are added to the reaction container in the above proportions and stirred until uniform. The speed during stirring is preferably 600-800 RPM and the stirring time is preferably 10 minutes. Then a certain amount of sand beads are added and ground to a fineness of less than 10 μm, more preferably less than 5 μm, to obtain antibacterial / antiviral intermediates 1-4 respectively.

[0107] Example 1

[0108] Prepare a coating composition resistant to deep embossing according to the amounts of raw materials shown in Table 1, specifically:

[0109] (1) Add 40 - 50% saturated polyester resin, 30 - 40% S150 solvent, and 1 part of dispersant BYK110 to a reaction vessel, stir at a speed of 600 - 800 RPM for 10 minutes to mix evenly, then add titanium dioxide, and prepare a semi-finished white paste through grinding and filtration, controlling its fineness to be less than 10 μm;

[0110] (2) In the same manner, add 30 - 40% saturated polyester resin, 20 - 30% S150 solvent, and 1 part of dispersant BYK110 to a reaction vessel, stir at a speed of 600 - 800 RPM for 10 minutes to mix evenly, then add carbon black, and prepare a semi-finished black paste through grinding and filtration, controlling its fineness to be less than 10 μm;

[0111] (3) Under stirring, add the above-mentioned black paste, white paste, the remaining saturated polyester resin, S150 solvent, amino resin, antibacterial / antiviral intermediate, catalyst, and other auxiliary materials, and disperse and mix evenly;

[0112] (4) Adjust the viscosity of the resulting mixture to 100 - 140 s (measured with a Coat - 4 cup) to obtain the coating composition.

[0113] Primer coating and panel preparation: Take the self-produced primer of Nippon Paint with the model FLC 646, roll - coat it on a 0.5 mm pre - treated galvanized steel plate using a wire bar, and bake it in an oven at 300 °C for 40 s, with the metal plate temperature PMT: 216 °C, to obtain a primer with a film thickness of 7 μm.

[0114] Top - coat coating and panel preparation: Roll - coat the above - prepared coating composition (i.e., top - coat) on the above - mentioned primer of this example using a wire bar, and bake it in an oven at 300 °C for 40 s, with the metal plate temperature PMT: 216 °C, to obtain a top - coat with a film thickness of 15 μm.

[0115] Embossed plate sample preparation: Put the prepared sample plate into an embossing machine to prepare sample plates with embossing depths of 50 μm and 70 μm respectively.

[0116] Table 1. Raw material composition table of examples and comparative examples

[0117]

[0118] Examples 2, 3, 5 and Comparative Examples 1-3, 5

[0119] The raw material compositions of the coating compositions in Examples 2, 3, 5, Comparative Examples 1 - 3, and 5 are as shown in Table 1 above, and their preparation methods are similar to that of Example 1.

[0120] Among them, the methods for applying the primer coating and the topcoat coating are also the same as those described in Example 1.

[0121] Example 4, Comparative Example 4

[0122] In Example 4 and Comparative Example 4, the raw material compositions of the coating compositions are shown in Table 1. Their preparation methods are similar to those of Example 1, except that in this coating composition, metal or non-metal flake pigments with a metallic texture are added to the coating to increase the dazzling color effect, and titanium dioxide and carbon black are not used. At the same time, when using metal or non-metal flake pigments with a metallic texture, there is no need for grinding and filtering steps during the preparation process, but pre-soaking is required to wet it and uniformly disperse it in the solvent.

[0123] In Example 4 and Comparative Example 4, the metal or non-metal flake pigments with a metallic texture added are aluminum silver paste pigment SBCJ 72010. Aluminum silver paste often requires a pre-soaking step and is added to the premixed formula in step (2).

[0124] The pre-soaking step is as follows: The aluminum silver paste pigment SBCJ 72010 is pre-added to a part of S150 solvent and soaked at room temperature for 1-3 hours to ensure that the aluminum silver paste pigment is fully and uniformly wetted and dispersed in the solvent to obtain a metallic semi-finished color paste.

[0125] Among them, the methods for applying the primer coating and the topcoat coating are also the same as those described in Example 1.

[0126] It should be noted that:

[0127] Comparative Example 1 used 20 parts of an antibacterial / antiviral intermediate. The content of this antibacterial / antiviral intermediate has exceeded the scope of the present invention. Therefore, this Comparative Example 1 is only used as a comparative example.

[0128] The resin OF-67 used in Comparative Examples 2-4 is an unmodified saturated polyester resin produced by Nippon Paint Co., Ltd. It cannot achieve an ideal effect, so it is not the preferred resin of the present invention. Therefore, Comparative Examples 2-4 are used as comparative examples.

[0129] Comparative Example 5 used 1 part of an antibacterial / antiviral intermediate. The content of this antibacterial / antiviral intermediate has been less than the scope of the present invention. Therefore, this Comparative Example 5 is only used as a comparative example.

[0130] Test Example

[0131] The formed paint films in Examples 1-5 and Comparative Examples 1-6 were tested.

[0132] Test methods and standards:

[0133] Unless otherwise stated, the performance of the color-coated plates in the examples and comparative examples of the present invention was tested in accordance with the national standard GB / T 13448-2006, and the results met the requirements of the national standard GB / T 13448-2006.

[0134] Requirements for solvent wipe test of flat plates: Specimen preparation, test environment, and test procedures as specified in 10.2 of GB / T 13448-2006. By the manual method, wrap the index finger with a cotton gauze and immerse it in the butanone solution, and wipe 120 times (50 times for metallic aluminum powder and special applications) on the sample plate with an arm force of about 10 N, then compare with the un-wiped part. The part of the coating surface wiped with the organic solution butanone (MEK) should show no visible color difference and no coating damage. The specific test method can refer to the enterprise standard Q / HR 0502 008-2009 of Haier Group.

[0135] Requirements for solvent wipe test of embossed plates: Specimen preparation, test environment, and test procedures as specified in 10.2 of GB / T 13448-2006. By the manual method, wrap the index finger with a cotton gauze and immerse it in the butanone solution, and wipe 70 times (50 times for metallic aluminum powder and special applications) on the embossed sample plate (embossing depth 50 μm) with an arm force of about 10 N, then compare with the un-wiped part. The part of the coating surface wiped with the organic solution butanone (MEK) should show no visible color difference and no coating damage. Similarly, for an embossing depth of 70 μm, the wiping times are 50 times (30 times for metallic aluminum powder and special applications).

[0136] Requirements for solvent wipe test of flat plate bending: Specimen preparation, test environment, and test procedures as specified in 10.2 of GB / T 13448-2006. Bend the standard sample plate at 120 °C, and by the manual method, wrap the index finger with a cotton gauze and immerse it in the butanone solution, and wipe 30 times at the bent part of the sample plate with an arm force of about 10 N, then compare with the un-wiped part. The part of the coating surface wiped with the organic solution butanone (MEK) should show no visible color difference and no coating damage.

[0137] The antibacterial and antiviral performance tests described in the present invention were all entrusted to the Guangzhou Institute of Microbiology for testing.

[0138] For the antibacterial performance of the sample plates, the performance of the color-coated plates in the examples and comparative examples of the present invention was tested in accordance with the national standard GB / T 21866-2008, and the results met the requirements of the national standard GB / T 21866-2008.

[0139] For the anti-mildew performance of the sample plates, the performance of the color-coated plates in the examples and comparative examples of the present invention was tested in accordance with the national standard GB / T 1741-2007 Determination of Resistance of Paint Films to Mildew, and the results met the requirements of the national standard GB / T 1741-2007.

[0140] The anti-viral performance of the samples was tested according to the Group Standard "Antibacterial and Anti-viral Coatings" formulated by the China National Coatings Industry Association in 2020 for the performance of color-coated plates in both the examples and comparative examples of the present invention, and the results met the requirements of the Group Standard "Antibacterial and Anti-viral Coatings" formulated by the China National Coatings Industry Association.

[0141] The test results of the key performance of the samples are shown in Table 2 below.

[0142] Table 2. Test Results of Key Performance of the Topcoat Coated Plates Prepared in Examples and Comparative Examples

[0143]

[0144]

[0145] From the results in Table 2, it can be found that the paint films formed by the coating compositions in Examples 1-5 of the present invention not only meet the requirements of the national standard GB / T 13448-2006, but also meet the requirements of the enterprise standard Q / HR 0502008-2009 of Haier Group, the highest general standard in the industry. Especially when the embossing depth exceeds 70 μm, excellent solvent-resistant wiping performance is still exhibited.

[0146] In Comparative Examples 2 to 4, the conventional OF-67 resin produced by Nippon Paint was used, and when the embossing depth was 50 μm, the MEK resistance did not meet the standard.

[0147] This shows that the coating composition provided by the present invention has good deep embossing processing resistance, solvent-resistant wiping performance of deeply embossed plates, and acid and alkali resistance while ensuring conventional properties.

[0148] Tables 3 and 4 shown below present the antibacterial / anti-viral test results of the samples. Since the comparative examples 2 to 4 must first generally meet the performance requirements of embossing resistance, and they can no longer meet this requirement, the following Tables 3 and 4 only give the test results of Comparative Example 1 and Comparative Example 5.

[0149] Table 3. Test Results of Antibacterial Activity Values of the Topcoat Coated Plates Prepared in Examples and Comparative Examples

[0150]

[0151]

[0152] Table 4. Test Results of Anti-viral Activity Values of the Topcoat Coated Plates Prepared in Examples and Comparative Examples

[0153]

[0154] The above test results show that, compared with traditional polyester resins, the paint film formed by the coating composition provided by the present invention has better deep embossing processing resistance and shows strong solvent resistance test performance in both embossing MEK and impact MEK.

[0155] From the perspective of antibacterial and antiviral performance tests, the paint film formed by the coating composition provided by the present invention has broad-spectrum antibacterial / antiviral capabilities. It has a significant killing effect on the bacteria specified in the national standard and fully meets the highest requirements of the national standard. At the same time, the paint film formed by the coating composition provided by the present invention, under the synergistic effect of the preferred antibacterial agent, shows outstanding antiviral capabilities. It can not only meet the two viruses (H3N2, hand-foot-and-mouth virus) specified by the China Coatings Industry Association, reaching Class I antiviral activity, but also shows broad-spectrum antiviral capabilities.

[0156] In addition, for other properties not listed in this table, which are known to those skilled in the art, the performance requirements can be met.

[0157] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not limitations on the implementation manners of the present invention. For those of ordinary skill in the art, based on the above description, other different forms of changes or variations can be made. It is impossible to list all the implementation manners here. Any obvious changes or variations derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. An anti-deep embossing and antibacterial / antiviral coating composition for a primed coil or substrate, wherein, Its components by mass parts include: 30 - 70 parts of polyester resin; 2 - 25 parts of curing agent; 0.1 - 30 parts of colorant; 5 - 15 parts of solvent; 0.1 - 15 parts of antibacterial / antiviral intermediate; 0.1 - 2 parts of catalyst; 0.01 - 10 parts of auxiliary component; The polyester resin is a modified saturated polyester resin; the modified saturated polyester resin is an epoxy resin - modified and / or acrylic resin - modified saturated polyester resin; the acid value of the polyester resin is 3 - 8mg KOH / g, the hydroxyl value is 20 - 30mgKOH / g, the solid content is 55 - 65wt%, and the molecular weight is 3000 - 6000; The components of the antibacterial / antiviral intermediate include: polyester resin, solvent, antibacterial / antiviral agent, dispersant, and stabilizer; The antibacterial / antiviral intermediate consists of antibacterial / antiviral intermediate 1 and antibacterial / antiviral intermediate 2. The antibacterial / antiviral agent in antibacterial / antiviral intermediate 1 is Guardiant, and the antibacterial / antiviral agent in antibacterial / antiviral intermediate 2 is BM - 102SVP02.

2. The coating composition according to claim 1, characterized in that The curing agent is an amino resin.

3. The coating composition according to claim 2, wherein The amino resin is selected from at least one or several of melamine formaldehyde resin, methyl - etherified urea - formaldehyde resin, methyl - etherified melamine resin, butyl - etherified urea - formaldehyde resin, butyl - etherified melamine resin, and phenyl - substituted melamine formaldehyde resin.

4. The coating composition according to claim 3, characterized in that The amino resin is selected from methyl - etherified melamine resin and / or butyl - etherified melamine resin.

5. The coating composition according to claim 2, characterized in that The components of the antibacterial / antiviral intermediate by mass parts include: 30 - 60 parts of polyester resin, 15 - 30 parts of solvent, 30 - 60 parts of antibacterial / antiviral agent, 0.1 - 1.2 parts of dispersant, and 0.2 - 0.8 parts of stabilizer.

6. The coating composition according to claim 1, characterized in that The polyester resin in the components of the antibacterial / antiviral intermediate is a modified polyester resin.

7. The coating composition according to claim 6, characterized in that The fineness of the antibacterial / antiviral intermediate is less than 15μm.

8. The coating composition according to claim 7, wherein The fineness of the antibacterial / antiviral intermediate is less than 10μm.

9. The coating composition according to claim 8, characterized in that The fineness of the antibacterial / antiviral intermediate is less than 5μm.

10. The coating composition according to claim 1, characterized in that, The embossing depth obtained based on the coating composition is 10 - 100μm.

11. The coating composition according to claim 10, wherein The embossing depth obtained based on the coating composition is 30 - 80μm.

12. The coating composition according to claim 11, characterized in that, The embossing depth obtained based on the coating composition is 50 - 70μm.

13. A method for preparing the coating composition as described in any one of claims 1 - 12, which includes the following steps: (1) Mix the polyester resin, solvent, antibacterial / antiviral agent, dispersant, and stabilizer in the components of the antibacterial / antiviral intermediate in a certain proportion to obtain the antibacterial / antiviral intermediate; (2) Premix a part of the polyester resin, a part of the solvent, pigment, and a part of the auxiliary in the components of the coating composition in a certain proportion and grind them to a fineness not greater than 10μm, and filter to obtain a semi - finished product color paste; (3) Disperse and mix evenly the remaining polyester resin, the remaining solvent, curing agent, the semi - finished product color paste, antibacterial / antiviral intermediate, catalyst, and auxiliary in the components of the coating composition. The fineness of the mixture after mixing is less than 20μm; (4) Adjust the viscosity of the obtained product to a viscosity of 100 - 140 s for a No. 4 cup, thereby obtaining the coating composition.

14. The method for preparing the coating composition according to claim 13, characterized in that, In the step (3), the fineness of the mixture is less than 15 μm.

15. Use of the coating composition according to any one of claims 1 - 12, which is used for coating a primed coil or substrate.

16. Use of the coating composition according to claim 15, characterized in that, The coil or substrate includes cold-rolled steel, polished steel, pickled steel, iron phosphate-treated steel, zinc phosphate-treated steel, hot-dip galvanized steel, zinc-aluminum-magnesium alloy, electro-galvanized steel sheet, tin-plated steel sheet, stainless steel, aluminum alloy, brass.

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