Water-based self-lubricating fingerprint-resistant coating, its preparation method and application

Abstract

The present application discloses an aqueous self-lubricating fingerprint-resistant coating, its preparation method and application. By weight percentage, the coating comprises the following components: compounded silica 5% - 10%, coupling agent 5% - 12%, compounds of molybdenum, vanadium, titanium or zirconium 0.1% - 5%, flash rust inhibitor 0.1% - 2%, anti-scratch aid 1% - 5% and water 66% - 88.8%; wherein, the compounded silica is composed of nanoscale silica and submicron-scale silica. This coating can be directly used for passivating the surface of metal substrates, significantly improving the wear resistance, corrosion resistance and anti-scratch property of the metal substrates. It can also be used on the surface of metal workpieces to be deep-drawn, achieving the purpose of simultaneously polishing and passivating the metal surface, significantly improving the glossiness, corrosion resistance and anti-scratch property of the processed surface of the workpieces, reducing the surface roughness, and broadening the application scope of the product to meet different market demands.

Description

Technical Field

[0001] This application belongs to the technical field of coatings, and specifically relates to an aqueous self-lubricating fingerprint-resistant coating, its preparation method and application. Background Art

[0002] Galvanizing the steel plate surface is an economical and effective rust prevention method. Approximately half of the world's zinc is used in this process. The steel plate obtained after galvanizing is called a galvanized steel plate and is widely used in the automotive, building materials, household appliances, and mechanical and electrical industries.

[0003] Although the galvanized layer can improve the corrosion resistance of metals, problems such as white rust and even red rust are still likely to occur during use. Moreover, most galvanized steel plates need to be stamped into shape before being put on the market. During the stamping process, on the one hand, due to the friction between the mold and the steel plate, the coating is prone to problems such as cracking and powdering during forming, which affects the appearance quality, dimensional accuracy, and corrosion resistance of the formed parts, and will also exacerbate the wear of the mold and reduce its service life. On the other hand, some usage scenarios require that the deep-drawn surface be a bright surface, the unprocessed surface be the natural color of the galvanized layer or the coating, and both the processed surface and the unprocessed surface maintain excellent corrosion resistance. There is no report in the industry on coatings that meet this requirement. Summary of the Invention

[0004] Based on this, this application provides an aqueous self-lubricating fingerprint-resistant coating. When it is used on the metal surface, such as the galvanized steel plate surface, it can significantly enhance the corrosion resistance of the galvanized steel plate, maintain a good appearance, and is suitable for the deep-drawing process. It can make the processed surface of the workpiece after deep drawing have a high gloss and a low surface roughness, and both the processed surface and the unprocessed surface maintain excellent corrosion resistance.

[0005] The technical solution adopted in this application is an aqueous self-lubricating fingerprint-resistant coating, which, in terms of weight percentage, includes the following components:

[0006] Compound silica 5% - 10%,

[0007] Coupling agent 5% - 12%,

[0008] Compounds of molybdenum, vanadium, titanium or zirconium 0.1% - 5%,

[0009] Flash rust inhibitor ০.১% - 2%,

[0010] Anti-scratch additive 1% - 5% and

[0011] Water 66% - 88.8%;

[0012] Among them, the compound silica is composed of nanoscale silica and submicron-scale silica.

[0013] In one embodiment, denoting the particle size as D, by weight percentage of the compounded silica, the compounded silica comprises the following components:

[0014] 15% - 40% of first silica with 1nm ≤ D ≤ 50nm,

[0015] 15% - 40% of second silica with 50nm < D ≤ 100nm and

[0016] 30% - 70% of third silica with 100nm < D ≤ 1μm.

[0017] In one embodiment, the weight ratio of the first silica, the second silica and the third silica is 1:(0.8 - 1.2):(1.5 - 3).

[0018] In one embodiment, by weight percentage of the compounded silica, the compounded silica comprises the following components:

[0019] 15% - 40% of first silica with 1nm ≤ D ≤ 50nm,

[0020] 15% - 40% of second silica with 50nm < D ≤ 100nm and

[0021] 30% - 70% of third silica with 100nm < D ≤ 200nm.

[0022] In one embodiment, the coupling agent comprises one or a combination of more of silane coupling agents and titanate coupling agents.

[0023] In one embodiment, the silane coupling agent is selected from one or a combination of more of amino silane coupling agents, epoxy group silane coupling agents and vinyl silane coupling agents.

[0024] In one embodiment, the titanate coupling agent is selected from one or a combination of more of monoalkoxy type, monoalkoxy pyrophosphate type, chelating type and coordination type titanate coupling agents.

[0025] In one embodiment, the anti - flash rust agent is selected from one or a combination of more of organic amine - type anti - flash rust agents, phosphate - type anti - flash rust agents, nitrite - type anti - flash rust agents, silicate - type anti - flash rust agents, benzoate - type anti - flash rust agents, organic zinc salt - type anti - flash rust agents and organic calcium salt - type anti - flash rust agents.

[0026] In one embodiment, in the aqueous self - lubricating fingerprint - resistant coating, the anti - scratching aid is compounded from anti - scratching aids with different particle sizes.

[0027] In one embodiment, the anti-scratch aid is composed of a first anti-scratch aid with a particle size of 0.1 μm to 0.5 μm and a second anti-scratch aid with a particle size of 1 μm to 3 μm in a weight ratio of 1:(1 to 2).

[0028] In one embodiment, the anti-scratch aid is selected from one or a combination of polyethylene, polytetrafluoroethylene, polyethylene oxide, and silicone dispersions.

[0029] Another object of the present application is to provide a method for preparing the above-mentioned water-based self-lubricating fingerprint-resistant coating, comprising the following steps:

[0030] Mix the compounded silica, coupling agent, compounds of molybdenum, vanadium, titanium or zirconium, anti-flash rust agent, and anti-scratch aid in water.

[0031] Another object of the present application is to provide a metal material, at least one surface of which is coated with a coating formed by the above-mentioned water-based self-lubricating fingerprint-resistant coating.

[0032] Another object of the present application is to provide a deep-drawing workpiece, at least one surface of which is coated with a coating formed by the above-mentioned water-based self-lubricating fingerprint-resistant coating.

[0033] The present application has at least the following beneficial effects: Silica has excellent wear resistance and corrosion resistance, can efficiently passivate the surface of the metal substrate. When different particle size silicas are used in combination, the small particle size silica fills the gaps between the large particle size particles. In combination with the coupling agent, it can reduce film-forming defects, improve adhesion, reduce surface roughness, and further enhance the corrosion resistance and wear resistance of the fingerprint-resistant coating. By using compounds of molybdenum, vanadium, titanium or zirconium and anti-flash rust agent in combination, the corrosion resistance of the fingerprint-resistant coating on the metal substrate surface can be further improved. By using anti-scratch aid in combination, the slipperiness of the fingerprint-resistant coating is enhanced, and the anti-scratch property, wear resistance and corrosion resistance of the coating are further enhanced.

[0034] For the metal workpiece to be deep-drawn, sub-micron (particle size of 100 nm to 1 μm) silica and nano-scale silica (particle size < 100 nm) have high hardness and good wear resistance. In combination with the coupling agent, other additives and the deep-drawing process, the metal substrate can be efficiently polished, achieving extremely high polishing accuracy, reducing the surface roughness of the substrate, significantly improving the gloss of the processed surface, and enhancing the corrosion resistance of the processed surface. In addition, the unprocessed surface maintains excellent anti-scratch and corrosion resistance.

[0035] It can be seen that through the synergistic cooperation of each component, the present application obtains an aqueous self-lubricating fingerprint-resistant coating with excellent comprehensive performance. On the one hand, it can be directly used on the surface of a passivated metal substrate, significantly improving the wear resistance, corrosion resistance and scratch resistance of the metal substrate and maintaining a good appearance. On the other hand, it can be used for a metal workpiece to be deep-drawn, capable of achieving the purpose of simultaneously polishing and passivating the surface of the substrate, reducing the surface roughness, significantly improving the gloss of the processed surface of the workpiece, achieving a bright surface effect, and improving the corrosion resistance and scratch resistance, maintaining a good appearance, and broadening the application scope of the product to meet different market demands. Description of the Drawings

[0036] Figure 1 FIG. is the effect diagram after the deep-drawing process of a galvanized steel sheet passivated with the aqueous self-lubricating fingerprint-resistant coating in Example 1 of the present application;

[0037] Figure 2 FIG. is the effect diagram after the deep-drawing process of a galvanized steel sheet passivated with the aqueous self-lubricating fingerprint-resistant coating in Example 2 of the present application. Detailed Embodiments

[0038] The specific embodiments and drawings of the present application are only for illustrative purposes and should not be construed as limitations on the present application. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present application more thorough and comprehensive.

[0039] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs. The terms used in the description of the present application in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0040] In the present application, "and / or" includes any and all combinations of one or more of the related listed items. The "including", "having" and "comprising" described in the present application are intended to cover non-exclusive inclusion. Unless a clear limiting term is used, such as "only", "consisting of", etc., another component can be added.

[0041] In this application, "preferably", "more preferably", "more desirably", "even more desirably", etc. refer to embodiments of this application that can provide certain beneficial effects in certain circumstances. However, in the same circumstances or other circumstances, other embodiments may also be preferred. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not available, nor is it intended to exclude other embodiments from the scope of this application. That is, in this application, "preferably", "more preferably", "more desirably", "even more desirably", etc. are only used to describe embodiments or examples with better effects, but do not constitute a limitation on the protection scope of this application. Similarly, "further", "even further", "especially", etc. are only used for descriptive purposes to indicate differences in content, but should not be construed as a limitation on the protection scope of this application.

[0042] In this application, "A and B are each independently selected from x, y, or z" means that A and B are independent events, and the occurrence of event A does not affect the occurrence of event B. Therefore, when A is selected from x, B can be selected from any one of x, y, or z; when A is selected from y, B can be selected from any one of x, y, or z; when A is selected from z, B can be selected from any one of x, y, or z.

[0043] When a numerical range is disclosed in this application, the above range is considered continuous and includes the minimum and maximum values of the range, as well as each value between such minimum and maximum values. Further, when the range refers to integers, it includes each integer between the minimum and maximum values of the range. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be combined. In other words, unless otherwise specified, all ranges disclosed in this application should be understood to include any and all sub-ranges subsumed therein.

[0044] If there is no special indication, all steps of this application can be carried out in sequence or randomly. For example, the method includes steps (a) and (b), which means that the method can include steps (a) and (b) carried out in sequence, or can also include steps (b) and (a) carried out in sequence. For example, when it is mentioned that the method may further include step (c), it means that step (c) can be added to the method in any order. For example, the method can include steps (a), (b), and (c) in sequence, or can also include steps (a), (c), and (b), or can also include steps (c), (a), and (b), etc.

[0045] In this application, "above" or "below" both include the number itself. For example, below 1 includes 1.

[0046] In this application, room temperature refers to 0°C to 60°C, including but not limited to 10°C to 40°C, or further 20°C to 30°C.

[0047] In this application, the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first", "second", and "third" may explicitly or implicitly include at least one of such features.

[0048] In this application, the meaning of "multiple" or "several" is at least two, such as two, three, etc., unless otherwise specifically defined. The meaning of "a number of" is at least one, such as one, two, three, etc., unless otherwise specifically defined. "At least one kind" means any one kind, any two kinds, or any two or more kinds. Unless otherwise mentioned, terms in the singular form may include the plural form and should not be construed as having a quantity of one.

[0049] In this application, for orientation terms, if there are terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation and positional relationship is based on the orientation or positional relationship shown in the drawings. This is only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of this application.

[0050] When describing the positional relationship, unless otherwise specified, when an element such as a layer, film, or substrate is referred to as being "on" another film layer, it can be directly on the other film layer or there may also be an intermediate film layer. Further, when a layer is referred to as being "under" another layer, it can be directly below or there may be one or more intermediate layers. It can also be understood that when a layer is referred to as being "between" two layers, it can be the only layer between the two layers or there may also be one or more intermediate layers.

[0051] Galvanized steel sheets are widely used in the automotive, building materials, household appliances, and mechanical and electrical industries. However, traditional galvanized steel sheets are prone to white rust or even red rust problems during use. Moreover, most galvanized steel sheets need to be formed by stamping (such as deep drawing process) before they can be put into market use. During the stamping process, problems such as cracking, powdering, and blackening of the galvanized layer are likely to occur, affecting the appearance quality, dimensional accuracy, and corrosion resistance of the formed parts. In addition, some use scenarios require that the processed surface after deep drawing be a bright surface, the unprocessed surface be the natural color of the galvanized layer or the coating, and both the processed surface and the unprocessed surface maintain excellent corrosion resistance, but no coatings that can meet this requirement have been found.

[0052] To solve the above problems, this application provides an aqueous self-lubricating fingerprint-resistant coating, which, by weight percentage, comprises the following components:

[0053] 5% - 10% of compounded silica

[0054] 5% - 12% of coupling agent

[0055] 0.1% - 5% of compounds of molybdenum, vanadium, titanium or zirconium

[0056] 0.1% - 2% of anti - flash rust agent

[0057] 1% - 5% of anti - scratching additive and

[0058] 66% - 88.8% of water

[0059] Among them, the compounded silica is composed of nano - scale silica and sub - micron - scale silica.

[0060] In this application, silica (silicon dioxide) has excellent corrosion resistance and can efficiently passivate the surface of the metal substrate. When different particle - size silicas are compounded and used, the small - particle - size silica can fill the gaps between the large - particle - size particles. With the coupling agent used in combination, it can reduce the film - forming defects, make the coating more dense, reduce the surface roughness, and prevent the corrosive medium from contacting the substrate, further improving the corrosion resistance, weather resistance and durability of the coating. Moreover, by utilizing the high hardness and wear resistance of silica and cooperating with other components in the coating, the scratch resistance and wear resistance of the fingerprint - resistant coating can be significantly improved. In addition, the high specific surface area and surface energy of nano - scale silica can also enhance the adhesion between the coating and the substrate and, as a reinforcing material, improve the overall strength of the coating. By using compounds of molybdenum, vanadium, titanium or zirconium and anti - flash rust agent in combination, the adhesion and corrosion resistance of the fingerprint - resistant coating on the surface of the metal substrate (such as galvanized steel) can be further improved. And by using anti - scratching additives in combination, the smoothness of the fingerprint - resistant coating can be enhanced, and the scratch resistance, wear resistance and corrosion resistance of the coating can be further enhanced. Directly applying the water - based self - lubricating fingerprint - resistant coating of this application to passivate the surface of the metal substrate can significantly enhance the wear resistance, corrosion resistance and scratch resistance of the substrate and maintain a good appearance.

[0061] For the metal workpiece to be deep - drawn, during the deep - drawing process, the sub - micron - scale (particle size of 100 nm - 1 μm) silica and nano - scale silica (particle size < 100 nm) have high hardness and good wear resistance. By using the coupling agent and other additives in combination with the deep - drawing process, the metal substrate can be efficiently polished, achieving extremely high polishing precision, reducing the surface roughness of the substrate, significantly enhancing the gloss of the processed surface, and enhancing the corrosion resistance of the processed surface. Moreover, both the processed surface and the unprocessed surface maintain excellent scratch - resistance and corrosion - resistance performance, achieving the purpose of simultaneously polishing and passivating the surface of the processed substrate.

[0062] Understandably, based on weight percentage, the water-based self-lubricating fingerprint-resistant coating described in this application includes 5% - 10% of compounded silica, including but not limited to 5%, 6%, 7%, 8%, 9% or 10%. If it is less than 5%, the corrosion resistance, scratch resistance and fingerprint resistance of the coating are insufficient; if it is higher than 10%, the compactness of the coating is insufficient, which will also lead to insufficient corrosion resistance, as well as poor adhesion and impact resistance. In one embodiment, based on weight percentage, the water-based self-lubricating fingerprint-resistant coating includes 5% - 8% of compounded silica.

[0063] In one embodiment, represented by D as the average particle size, based on the weight percentage of the compounded silica, the compounded silica includes the following components:

[0064] 15% - 40% of the first silica with 1nm ≤ D ≤ 50nm,

[0065] 15% - 40% of the second silica with 50nm < D ≤ 100nm and

[0066] 30% - 70% of the third silica with 100nm < D ≤ 1μm.

[0067] Using the first silica (nanoscale silica) with 1nm ≤ D ≤ 50nm, the second silica (nanoscale silica) with 50nm < D ≤ 100nm and the third silica (submicron-scale silica) with 100nm < D ≤ 1μm for compounded use can better coordinate the polishing speed and polishing accuracy, make the surface of the substrate quickly smooth and bright, and achieve the purpose of simultaneously polishing and passivating the surface of the processed surface of the substrate.

[0068] In one embodiment, based on the weight percentage of the compounded silica, the compounded silica includes the following components:

[0069] 20% - 35% of the first silica with 1nm ≤ D ≤ 50nm,

[0070] 20% - 35% of the second silica with 50nm < D ≤ 100nm and

[0071] 35% - 60% of the third silica with 100nm < D ≤ 1μm.

[0072] In one embodiment, the weight ratio of the first silica, the second silica and the third silica is 1:(0.8 - 1.2):(1.5 - 3).

[0073] Furthermore, through the inventors' research, it is found that within a certain range, the smaller the particle size of silica, the larger the specific surface area, the higher the surface energy, the better the dispersibility, and it is easier to form a stable colloidal solution (silica sol), which is used as a film-forming substance in coatings and can significantly improve the film-forming property of the coatings and the adhesion between the coatings and the substrate. In order to coordinate the film-forming property, adhesion, polishing speed and polishing accuracy in this application, nano-level silica sol and sub-micron-level silica sol are further selected and used in combination to obtain the compound silica described in this application. Further, silica sol with 100nm < D ≤ 200nm is used as the raw material for the sub-micron-level silica in this application. It can be understood that for silica sol, its silica accounts for a certain solid content, and the dosage needs to be correspondingly converted when formulating coatings with silica sol. The silica dosage described in this application refers to the solid dosage of silica.

[0074] It can be understood that this application does not impose special restrictions on the source of silica, and it can be commercially available. Exemplarily, it can be selected from Huierte, Lingwei, Baitexin, Delixin Micro-Nano, etc.

[0075] In this application, the coupling agent can improve the dispersibility of silica and the rheology of the coatings, and can interact with organic molecules (such as anti-flash rust agents and anti-scratch additives) and inorganic molecules (such as compounds of silica, molybdenum, vanadium, titanium or zirconium) in the water-based self-lubricating fingerprint-resistant coatings, significantly improving the adhesion of the coating to the substrate and reducing problems such as coating peeling and flaking. In addition, the coupling agent can also improve the hardness, wear resistance, corrosion resistance and aging resistance of the coating.

[0076] It can be understood that, by weight percentage, the water-based self-lubricating fingerprint-resistant coatings described in this application include 5% - 12% of the coupling agent, including but not limited to 5%, 6%, 7%, 8%, 9%, 10%, 11% or 12%. If it is less than 5%, the adhesion, alkali resistance, solvent resistance and corrosion resistance of the coating will decrease; if it is higher than 12%, it is unfavorable to the appearance, especially the appearance after stamping forming will deteriorate. In one of the embodiments, by weight percentage, the water-based self-lubricating fingerprint-resistant coatings include 5% - 10% of the silane coupling agent.

[0077] In one embodiment, the coupling agent includes one or a combination of more than one of a silane coupling agent and a titanate coupling agent. Both the silane coupling agent and the titanate coupling agent can chemically react with organic and inorganic molecules in the coating to form stable chemical bonds, increase the bonding force between the coating and the substrate, improve the adhesion of the coating, and enhance the water resistance, chemical resistance, corrosion resistance, weather resistance and durability of the coating, enabling the coating to better resist the erosion of natural factors such as sunlight, wind and rain in outdoor environments, reducing the occurrence of problems such as fading, cracking and chalking, and being resistant to salt spray and chemicals, thereby extending the service life of the coating; moreover, the silane coupling agent and the titanate coupling agent can also improve the dispersibility of silica and the leveling and thixotropy of the coating, and the silane coupling agent can also play a lubricating role in the coating, reducing the viscosity of the coating, making the coating easier to construct and apply. In addition, the silane coupling agent and the titanate coupling agent can also improve the abrasion resistance, hardness and impact resistance of the coating, making the coating more tough and durable.

[0078] In one embodiment, the silane coupling agent is selected from one or a combination of more than one of an amino silane coupling agent, an epoxy group silane coupling agent and a vinyl silane coupling agent. Further, the silane coupling agent is selected from one or a combination of more than one of γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-(2-aminoethyl)aminopropyltrimethoxysilane, N-(2-aminoethyl)aminopropylmethyldimethoxysilane, N-(2-aminoethyl)aminopropyltriethoxysilane, N-(2-aminoethyl)aminopropylmethyldiethoxysilane, N-(2-aminoethyl)aminopropylmethyldimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-isocyanatopropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)propyltrimethoxysilane. Exemplarily, the silane coupling agent described in the present application can be selected from one or a combination of more than one of KH-540, KH-550, KH-792, KH-560 and A-151.

[0079] In one embodiment, the titanate coupling agent is selected from one or a combination of more than one of a monoalkoxy type, a monoalkoxy pyrophosphate type, a chelating type (such as a product containing an oxyacetic acid chelating group or a product containing an ethylene glycol chelating group) and a coordination type. Further, the titanate coupling agent is selected from one or a combination of more than one of bis(octyl pyrophosphate) oxyacetate titanate and bis(dioctyl phosphate) ethylene glycol titanate. Exemplarily, the titanate coupling agent is selected from one or a combination of more than one of GR-311W, KR-238T, HY311W, NDZ-311, KR-238S and HC-WT.

[0080] In the present application, the compounds of molybdenum, vanadium, titanium or zirconium can be in the form of metal oxides, metal sulfides or metal silicides, or in the form of salts. Exemplarily, the compounds of molybdenum can be selected from one or more combinations of sodium molybdate, ammonium molybdate, molybdenum disulfide, molybdenum trioxide, molybdenum silicide and nickel molybdate. Exemplarily, the compounds of vanadium can be selected from one or more combinations of vanadium pentoxide, vanadium dioxide, ammonium metavanadate and sodium metavanadate. Exemplarily, the compounds of titanium can be selected from one or more combinations of titanium dioxide, titanate, potassium fluotitanate, ammonium fluotitanate, titanium alloy and titanium nickel yellow. Exemplarily, the compounds of zirconium can be selected from one or more combinations of zirconium oxide, zirconium nitrate, zirconium silicate, zirconium phosphate and zirconium fluorosalt.

[0081] In the present application, the compounds of molybdenum, vanadium, titanium or zirconium can improve the adhesion, corrosion resistance and scratch resistance of the coating to the substrate. Specifically, (1) Both the compounds of molybdenum and the compounds of vanadium can form a dense passivation film on the metal surface to prevent the corrosion medium (such as oxygen, water, chloride ions) from contacting the metal substrate, showing excellent corrosion inhibition effect; in addition, after the coating is scratched, both the molybdenum compound or the vanadium compound can react with water to generate new passivation substances to fill the scratches, thereby endowing the coating with a certain self-healing ability and good adhesion; the compounds of molybdenum (or vanadium) and the compounds of titanium (or zirconium) are used in combination to form a composite passivation film, synergistically improving the corrosion resistance of the coating. (2) Both the compounds of titanium and the compounds of zirconium can be used for corrosion resistance. Some compounds can also form good chemical bonding with the metal surface to enhance the adhesion of the coating, and the formed passivation film can effectively prevent the penetration of the corrosion medium, further improving the corrosion resistance of the coating; the compounds of titanium and the compounds of zirconium and the silane coupling agent are used in combination to form an organic-inorganic composite passivation film, which can improve the comprehensive performance of the coating, especially the corrosion resistance.

[0082] It can be understood that, by weight percentage, the water-based self-lubricating anti-fingerprint coating described in the present application includes 0.1% to 5% of the compounds of molybdenum, vanadium, titanium or zirconium, including but not limited to 0.1%, 0.2%, 0.3%, 0.5%, 0.6%, 0.8%, 0.9%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4% or 5%. If it is less than 0.1%, there is no obvious improvement in the corrosion resistance of the coating; if it is higher than 5%, it may lead to poor stability of the coating. In one embodiment, by weight percentage, the water-based self-lubricating anti-fingerprint coating includes 1% to 4% of the compounds of molybdenum, vanadium, titanium or zirconium.

[0083] Understandably, in the present application, a compound of molybdenum, a compound of vanadium, a compound of titanium, and a compound of zirconium can be used alone, or multiple compounds can be used in combination. In some of these embodiments, a compound of molybdenum, a compound of vanadium, a compound of titanium, and a compound of zirconium are selected for single use. In some of these embodiments, two or more of a compound of molybdenum, a compound of vanadium, a compound of titanium, and a compound of zirconium are selected for combined use.

[0084] In the present application, the anti-flash rust agent is mainly used to prevent the rapid oxidation of the surface of the metal substrate. Especially during the deep drawing process, under the dual effects of deep drawing and silica polishing, the fingerprint-resistant coating and the galvanized layer are damaged. The anti-flash rust agent forms a protective film on the metal surface to prevent moisture and oxygen from coming into contact with the metal, thereby delaying or preventing the occurrence of rust. In addition, by inhibiting the flash rust phenomenon on the metal surface, the anti-flash rust agent can ensure good adhesion between the coating and the metal surface, preventing the coating from peeling off due to rust. Moreover, when the anti-flash rust agent is combined with other components in the coating, it can provide long-term salt spray resistance and corrosion resistance protection, extend the service life of the metal, and also improve the appearance quality, prevent the metal surface from showing spots or corrosion marks due to flash rust, and maintain the beauty of the metal product.

[0085] Understandably, calculated by weight percentage, the waterborne self-lubricating fingerprint-resistant coating described in the present application includes 0.1% - 2% of the anti-flash rust agent, including but not limited to 0.1%, 0.2%, 0.3%, 0.5%, 0.6%, 0.8%, 0.9%, 1%, 1.5% or 2%. If it is less than 0.1%, there will be no obvious improvement in the corrosion resistance of the coating; if it is higher than 2%, it may reduce the adhesion, water resistance and corrosion resistance of the coating. In one of the embodiments, calculated by weight percentage, the waterborne self-lubricating fingerprint-resistant coating includes 0.1% - 1% of the anti-flash rust agent.

[0086] By reasonably selecting the anti-flash rust agent in the present application, the flash rust phenomenon on the surface of the galvanized sheet can be effectively inhibited, its service life can be extended, and the adhesion and corrosion resistance of the coating can be improved.

[0087] In one embodiment, the anti-flash rust agent is selected from one or a combination of more than one of organic amine anti-flash rust agents, phosphate anti-flash rust agents, nitrite anti-flash rust agents, silicate anti-flash rust agents, benzoate anti-flash rust agents, organic zinc salt anti-flash rust agents, and organic calcium salt anti-flash rust agents. Some anti-flash rust agents form a dense oxide film (such as iron oxide) on the metal surface through an oxidation reaction to achieve the purpose of anti-flash rust; some anti-flash rust agents form a precipitation film by reacting with the corrosive medium to achieve the purpose of anti-flash rust; and some anti-flash rust agents form a protective layer by adsorbing polar groups on the metal surface to achieve the purpose of anti-flash rust. It can be understood that a composite anti-flash rust agent can also be used in this application, which has the functions of a corrosion inhibitor, a passivator, and a shielding agent. Further, considering environmental protection, anti-flash rust effect, and the corrosion resistance of the subsequent coating comprehensively, the anti-flash rust agent preferably free of or low in nitrite and borate is selected in this application. Exemplarily, the anti-flash rust agent in this application is selected from one or a combination of more than one of Gorex HY-77, Elementis NALZIN® FA180, Synthro COR C E660 B of France, Halox FLASH-X® 150, and Borland R60.

[0088] In this application, the anti-scratch additive forms a protective layer on the coating surface, increasing the hardness and wear resistance of the coating, thereby effectively reducing the visibility of scratches and abrasions and extending the service life of the coating. Moreover, the anti-scratch additive can also significantly improve the leveling property and smoothness of the coating surface, reducing friction. In addition, the anti-scratch additive can enhance the chemical resistance and weather resistance of the coating, enabling it to still maintain good performance in harsh environments (such as high temperature, ultraviolet radiation, or acid-base environment, etc.), and also helps to improve the flexibility and crack resistance of the coating, reducing cracks generated by temperature changes or mechanical stress in the coating, making the self-lubricating fingerprint-resistant coating of this application particularly suitable for galvanized steel sheets and subsequent deep drawing processes.

[0089] It can be understood that, by weight percentage, the waterborne self-lubricating fingerprint-resistant coating in this application includes 1% - 5% of the anti-scratch additive, including but not limited to 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, or 5%. If it is less than 1%, the lubricity is insufficient; if it is higher than 5%, the corrosion resistance and solvent resistance of the coating may deteriorate. In one embodiment, by weight percentage, the waterborne self-lubricating fingerprint-resistant coating includes 2% - 4% of the anti-scratch additive.

[0090] In one embodiment, the anti-scratch additive is compounded from anti-scratch additives with different particle sizes.

[0091] In one embodiment, the anti-scratch additive is composed of a first anti-scratch additive with a particle size of 0.1 μm to 0.5 μm and a second anti-scratch additive with a particle size of 1 μm to 3 μm in a weight ratio of 1:(1 to 2). It can be understood that the particle size of the first anti-scratch additive includes but is not limited to 0.1 μm, 0.15 μm, 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm or 0.5 μm. The particle size of the second anti-scratch additive includes but is not limited to 1 μm, 1.5 μm, 2 μm, 2.5 μm or 3 μm. The anti-scratch additive with a large particle size has a lower specific gravity and can float on the surface of the coating to play an anti-scratch role. The specific gravity of the anti-scratch additive with a small particle size is close to that of the coating mixture and can penetrate the overall polymer network to improve the smoothness of the entire film layer. Through the compounding and synergy of anti-scratch additives with different particle sizes, the fingerprint-resistant coating exhibits high smoothness, anti-scratch property, wear resistance and corrosion resistance, thereby ensuring the secondary processing quality of metals (such as galvanized steel sheets).

[0092] In one embodiment, the anti-scratch additive is selected from one or a combination of polyethylene, polytetrafluoroethylene, oxidized polyethylene and silicone dispersions. It can be understood that the types of the first anti-scratch additive and the second anti-scratch additive are independent of each other and can be the same or different. Therefore, the first anti-scratch additive and the second anti-scratch additive are independently selected from one or a combination of polyethylene, polytetrafluoroethylene, oxidized polyethylene and silicone dispersions respectively.

[0093] In one embodiment, the anti-scratch additive is polyethylene wax. Utilizing the good chemical stability of polyethylene wax, the corrosion resistance, water resistance, chemical resistance and weather resistance of the coating are improved. Moreover, polyethylene wax can form a protective layer on the surface of the coating film, significantly improving the anti-scratch property and wear resistance of the coating. And due to its low coefficient of friction, it can improve the smoothness of the coating film and has the effect of optimizing the rheological properties of the coating, improving the workability. Further, through the compounding of polyethylene wax with different particle sizes and the synergistic cooperation with other components in the coating, the comprehensive performance of the coating is enhanced, especially the corrosion resistance, anti-scratch and wear resistance of the coating. Applying this coating to the surface of a passivated metal substrate can significantly enhance the wear and corrosion resistance of the metal substrate (such as galvanized steel sheet), thereby ensuring the secondary processing quality of the galvanized steel sheet. It is particularly suitable for the deep drawing process and can enable the workpiece after deep drawing to still maintain a good appearance and excellent wear and corrosion resistance. It can be understood that the source of the polyethylene wax in this application is not particularly limited and can be self-made or purchased. Exemplarily, the polyethylene wax described in this application can be selected from the aqueous wax emulsion products of Longhai Chemical Industry, Yijiu Chemical Industry or Wengkel.

[0094] Another object of this application is to provide a preparation method of the above-mentioned water-based self-lubricating fingerprint-resistant coating, including the following steps:

[0095] Mix the compounded silica, coupling agent, compounds of molybdenum, vanadium, titanium or zirconium, anti-flash rust agent and anti-scratch aid in water.

[0096] In one embodiment, the small-particle-size anti-scratch aid is added in portions, and the instantaneous shear force is increased through cyclic operations of stirring, stopping stirring and then restarting stirring, so that the small-particle-size anti-scratch aid is fully dispersed in the mixture, and the smoothness of the coating is further improved during film formation.

[0097] In one embodiment, the preparation method of the aqueous self-lubricating fingerprint-resistant coating includes the following steps:

[0098] S100: Under the condition of 40°C to 60°C, mix the compounded silica, coupling agent, compounds of molybdenum, vanadium, titanium or zirconium and anti-flash rust agent in water to prepare a first mixed solution;

[0099] S200: Slowly add a first anti-scratch aid with a particle size of 0.1 μm to 0.5 μm to the first mixed solution, adding it in 2 to 5 portions, and stirring for 10 min to 15 min after each addition; after the small-particle-size polyethylene wax dispersion is added, add a second anti-scratch aid with a particle size of 1 μm to 3 μm in multiple portions, and continuously stir for 5 min to 10 min.

[0100] Further, the stirring speed in step S100 is 100 rpm to 120 rpm. The stirring speed in step S200 is 200 rpm to 500 rpm.

[0101] Another object of the present application is to provide a metal material, at least one surface of which is coated with a coating formed by the aqueous self-lubricating fingerprint-resistant coating as described above. Further, the thickness of the coating is 0.5 μm to 3 μm.

[0102] In one embodiment, the metal material is steel, galvanized steel sheet, galvanized alloy steel sheet, aluminized steel sheet, aluminum sheet, chemically treated galvanized steel sheet, chemically treated galvanized alloy steel sheet, chemically treated aluminized steel sheet, chemically treated aluminum sheet or PCM steel sheet.

[0103] In one embodiment, the present application provides a galvanized steel sheet, at least one surface of which is coated with a coating formed by the aqueous self-lubricating fingerprint-resistant coating as described above. The fingerprint-resistant coating is continuous, uniform, smooth, flat, without traces (tensile marks, indentations, scratches, friction black lines) and stripes, showing good appearance. In addition, after testing, the galvanized steel sheet has excellent wear resistance, anti-scratch property, impact resistance, alkali resistance and corrosion resistance.

[0104] Another object of the present application is to provide a deep-drawing workpiece, at least one surface of which is coated with a coating formed by the water-based self-lubricating fingerprint-resistant coating as described above. Further, for the workpiece before deep drawing, its surface is coated with a coating formed by the water-based self-lubricating fingerprint-resistant coating as described above. After deep drawing, the glossiness of the processed surface (stretching / deep-drawing surface) of the deep-drawing workpiece increases, the surface roughness decreases, and the appearance is good; the unprocessed surface is coated with a coating formed by the water-based self-lubricating fingerprint-resistant coating of the present application (optionally, the thickness of the coating is 0.5 μm to 3 μm), the coating is continuous, uniform, smooth, flat, without traces (stretching marks, indentations, scratches, friction black lines) and stripes, and shows a good appearance. In addition, after testing, both the processed surface and the unprocessed surface have excellent abrasion resistance, scratch resistance, alkali resistance and corrosion resistance, enabling both the processed surface and the unprocessed surface to maintain their respective good appearances for a long time.

[0105] The technical solutions of the present application will be clearly and completely described below in conjunction with the accompanying drawings and specific embodiments. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present application, rather than all embodiments, and are only used to illustrate the present application and should not be construed as limiting the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present application. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For those reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0106] Raw material description:

[0107] (1) The description of the silica raw material is shown in Table 1 below.

[0108] Table 1

[0109]

[0110] The content of the compounded silica shown in the following examples all refers to the content of solid silica.

[0111] (2) Silane coupling agent: KH-550;

[0112] (3) Titinate coupling agent: HY311W.

[0113] (4) Anti-flash rust agent:

[0114] ① Anti-flash rust agent A: Halox FLASH-X® 150;

[0115] ② Anti-flash rust agent B: Borunlde R60.

[0116] (5) Polyethylene wax:

[0117] ① Polyethylene wax A: LHWAX®2140 wax emulsion, with a particle size less than 0.2 μm;

[0118] ② Polyethylene wax B: LHWAX®H2040B wax emulsion, with a particle size less than 0.5 μm;

[0119] ③ Polyethylene wax C: TL-201C wax emulsion from Longkou Yijiu Chemical Technology Co., Ltd., with a particle size of 0.5 μm - 1 μm;

[0120] ④ Polyethylene wax D: LHWAX®2545 wax emulsion, with a particle size of 1 μm - 3 μm;

[0121] ⑤ Polyethylene wax E: LHWAX®2548 wax emulsion, with a particle size of 5 μm - 8 μm.

[0122] Example 1

[0123] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method, which are as follows:

[0124] (1) By weight percentage, the composition of the aqueous self-lubricating fingerprint-resistant coating shown in this example is as follows:

[0125] Compound silica 8%,

[0126] Silane coupling agent 8%,

[0127] Potassium fluotitanate 2%,

[0128] Flash rust inhibitor A 1%,

[0129] Anti-scratch additive 2% and

[0130] Water 79%;

[0131] Among them, ① by weight percentage of the compound silica, the compound silica in this example includes the following components:

[0132] The first silica with 1 nm ≤ D ≤ 50 nm is 25%,

[0133] The second silica with 50 nm < D ≤ 100 nm is 25% and

[0134] The third silica with 100 nm < D ≤ 200 nm is 50%;

[0135] Among them, the raw material of the first silica is Huierte HS-830 silica sol with a particle size of 8 nm - 10 nm; the raw material of the second silica is Delixin Micro-Nano JA60-40 / 1 silica sol with a particle size of 55 nm - 65 nm; the raw material of the third silica is Delixin Micro-Nano JA110-40 / 1 silica sol with a particle size of 110 nm - 120 nm.

[0136] ② In this embodiment, the scratch-resistant additive is composed of LHWAX® 2140 polyethylene wax emulsion with a particle size less than 0.2 μm and LHWAX® 2545 polyethylene wax emulsion with a particle size of 1 μm to 3 μm in a weight ratio of 1:1.

[0137] (2) The preparation method of the water-based self-lubricating fingerprint-resistant coating in this embodiment is as follows:

[0138] S100: Mix the compounded silica, coupling agent, potassium fluotitanate and anti-flash rust inhibitor A in water under the condition of 40°C to 60°C to prepare the first mixed solution;

[0139] S200: Slowly add small-particle-size polyethylene wax A to the first mixed solution, adding it in 3 portions, and stirring for 15 min (rotation speed is 300 rpm) after each addition; after adding the small-particle-size polyethylene wax, add large-particle-size polyethylene wax D in 3 portions, continue stirring for 10 min (rotation speed is 300 rpm), and then fill.

[0140] Example 2

[0141] This embodiment provides a water-based self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the dosages of some components are different, specifically as follows:

[0142] (1) By weight percentage, the composition of the water-based self-lubricating fingerprint-resistant coating shown in this embodiment is as follows:

[0143] Compounded silica 8%,

[0144] Silane coupling agent 10%,

[0145] Potassium fluotitanate 4%,

[0146] Anti-flash rust inhibitor A 2%,

[0147] Scratch-resistant additive 4% and

[0148] Water 72%.

[0149] Example 3

[0150] This embodiment provides a water-based self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the dosages of some components are different, specifically as follows:

[0151] By weight percentage, the composition of the water-based self-lubricating fingerprint-resistant coating shown in this embodiment is as follows:

[0152] Compounded silica 7%,

[0153] Silane coupling agent 8%,

[0154] Potassium fluotitanate 0.5%,

[0155] Anti-flash rust inhibitor A 0.5%,

[0156] Scratch resistance aid 1% and

[0157] Water 83%.

[0158] Example 4

[0159] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the types of some components are different, specifically as follows:

[0160] (1) By weight percentage, the composition of the aqueous self-lubricating fingerprint-resistant coating shown in this example is as follows:

[0161] Compound silica 8%,

[0162] Titanate coupling agent 8%,

[0163] Zirconia 2%,

[0164] Anti-flash rust inhibitor B 1%,

[0165] Scratch resistance aid 2% and

[0166] Water 79%;

[0167] Among them, ① by weight percentage of the compound silica, the compound silica in this example includes the following components:

[0168] The first silica with 1nm ≤ D ≤ 50nm is 25%,

[0169] The second silica with 50nm < D ≤ 100nm is 25% and

[0170] The third silica with 100nm < D ≤ 200nm is 50%;

[0171] Among them, the first silica is compounded by mixing the Baite Xinhuiert HS-830 silica sol with a particle size of 8 nm to 10 nm and the Delixin Micro-Nano JA20-40 / 1 silica sol with a particle size of 15 nm to 20 nm in a weight ratio of 1:1; the second silica is compounded by mixing the Delixin Micro-Nano JA60-40 / 1 silica sol with a particle size of 55 nm to 65 nm and the Huierte HPHE / AAPS-IE-1912 silica sol with a particle size of 80 nm to 100 nm in a weight ratio of 1:1; the third silica is compounded by mixing the Delixin Micro-Nano JA110-40 / 1 silica sol with a particle size of 110 nm to 120 nm, the Huierte HPHE / SPS-SH-1813 silica sol with a particle size of 120 nm to 130 nm, and the Huierte HSD150 silica sol with a particle size of 140 nm to 160 nm in a weight ratio of 1:2:1.

[0172] ② The anti-scratch aid in this example is composed of the LHWAX® H2040B polyethylene wax emulsion with a particle size less than 0.5 μm and the LHWAX® 2545 polyethylene wax emulsion with a particle size of 1 μm to 3 μm in a weight ratio of 1:1.

[0173] Example 5

[0174] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the grades of some components are different, specifically as follows:

[0175] (1) By weight percentage, the composition of the aqueous self-lubricating fingerprint-resistant coating shown in this example is as follows:

[0176] Compound silica 8%,

[0177] Silane coupling agent B 8%,

[0178] Zirconia 2%,

[0179] Anti-flash rust agent B 1%,

[0180] Anti-scratch aid 2% and

[0181] Water 79%;

[0182] Among them, ① By weight percentage of the compound silica, the compound silica in this example includes the following components:

[0183] The first silica with 1 nm ≤ D ≤ 50 nm is 25%,

[0184] The second silica with 50 nm < D ≤ 100 nm is 25% and

[0185] The third silica with 100 nm < D ≤ 200 nm is 50%;

[0186] Among them, the first silica is composed of Wirt HS-830 silica sol with a particle size of 8 nm to 10 nm and Wirt HSD30 silica sol with a particle size of 20 nm to 40 nm, compounded in a weight ratio of 1:1; the second silica is composed of Wirt HSD80 silica sol with a particle size of 70 nm to 90 nm and Wirt HPHE / AAPS-IE-1912 silica sol with a particle size of 80 nm to 100 nm, compounded in a weight ratio of 1:1; the third silica is composed of Delixin Micro-Nano JA110-40 / 1 silica sol with a particle size of 110 nm to 120 nm, Wirt HPHE / SPS-SH-1813 silica sol with a particle size of 120 nm to 130 nm, and Wirt HSD150 silica sol with a particle size of 140 nm to 160 nm, compounded in a weight ratio of 1:1:1.

[0187] Example 6

[0188] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the composition of the compounded silica is different. Correspondingly, during the preparation of the coating, the corresponding raw materials are replaced, as follows:

[0189] Calculated by weight percentage of the compounded silica, the compounded silica in this example includes the following components:

[0190] The first silica with 1 nm ≤ D ≤ 50 nm is 22%,

[0191] The second silica with 50 nm < D ≤ 100 nm is 25% and

[0192] The third silica with 100 nm < D ≤ 200 nm is 53%;

[0193] Among them, the first silica is Wirt HS-830 silica sol with a particle size of 8 nm to 10 nm; the second silica is Delixin Micro-Nano JA60-40 / 1 silica sol with a particle size of 55 nm to 65 nm; the third silica is Delixin Micro-Nano JA110-40 / 1 silica sol with a particle size of 110 nm to 120 nm.

[0194] Example 7

[0195] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the composition of the compounded silica is different, as follows:

[0196] Calculated by weight percentage of the compounded silica, the compounded silica in this example includes the following components:

[0197] The first silica with 1 nm ≤ D ≤ 50 nm is 15%,

[0198] 15% of the second silica with 50nm < D ≤ 100nm and

[0199] 70% of the third silica with 100nm < D ≤ 200nm;

[0200] Among them, the first silica is the Wirth HS-830 silica sol with a particle size of 8nm to 10nm; the second silica is the Delixin Micro-Nano JA60-40 / 1 silica sol with a particle size of 55nm to 65nm; the third silica is the Delixin Micro-Nano JA110-40 / 1 silica sol with a particle size of 110nm to 120nm.

[0201] Example 8

[0202] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the composition of the compounded silica is different, specifically as follows:

[0203] Calculated by weight percentage of the compounded silica, the compounded silica in this example includes the following components:

[0204] 35% of the first silica with 1nm ≤ D ≤ 50nm,

[0205] 35% of the second silica with 50nm < D ≤ 100nm and

[0206] 30% of the third silica with 100nm < D ≤ 200nm;

[0207] Among them, the first silica is the Wirth HS-830 silica sol with a particle size of 8nm to 10nm; the second silica is the Delixin Micro-Nano JA60-40 / 1 silica sol with a particle size of 55nm to 65nm; the third silica is the Delixin Micro-Nano JA110-40 / 1 silica sol with a particle size of 110nm to 120nm.

[0208] Example 9

[0209] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the composition of the compounded silica is different, specifically as follows:

[0210] Calculated by weight percentage of the compounded silica, the compounded silica in this example includes the following components:

[0211] 25% of the first silica with 1nm ≤ D ≤ 50nm,

[0212] 25% of the second silica with 50nm < D ≤ 100nm and

[0213] 50% of the third silica with 100nm < D ≤ 1μm;

[0214] Among them, the first silica is the Wirt HS-830 silica sol with a particle size of 8 nm to 10 nm; the second silica is the Delixin Micro-Nano JA60-40 / 1 silica sol with a particle size of 55 nm to 65 nm; the third silica is the Brofos-silica-300 particle with a particle size of 300 nm.

[0215] Example 10

[0216] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the grade and dosage of some polyethylene wax emulsions are changed, resulting in different compositions of the anti-scratch additives. Correspondingly, during the preparation of the coating, the corresponding raw materials are replaced, as follows:

[0217] The anti-scratch additive in this example is composed of the TL-201C polyethylene wax emulsion with a particle size of 0.5 μm to 1 μm and the LHWAX® 2545 polyethylene wax emulsion with a particle size of 1 μm to 3 μm in a weight ratio of 1:1.

[0218] Example 11

[0219] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the grade and dosage of some polyethylene wax emulsions are changed, resulting in different compositions of the anti-scratch additives. Correspondingly, during the preparation of the coating, the corresponding raw materials are replaced, as follows:

[0220] The anti-scratch additive in this example is composed of the LHWAX® 2140 polyethylene wax emulsion with a particle size less than 0.2 μm and the LHWAX® 2548 polyethylene wax emulsion with a particle size of 5 μm to 8 μm in a weight ratio of 1:1.

[0221] Example 12

[0222] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the anti-scratch additives are not used in combination. Correspondingly, during the preparation of the coating, the corresponding raw materials are omitted, as follows:

[0223] In this example, the anti-scratch additive is the LHWAX® 2140 polyethylene wax emulsion with a particle size less than 0.2 μm.

[0224] Example 13

[0225] This example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the anti-scratch additives are not used in combination. Correspondingly, during the preparation of the coating, the corresponding raw materials are omitted, and the polyethylene wax composition is different, as follows:

[0226] In this embodiment, the scratch-resistant additive is the LHWAX® 2545 polyethylene wax emulsion with a particle size of 1 μm to 3 μm.

[0227] Comparative Example 1

[0228] This comparative example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that silica is not used in a compounded manner. Correspondingly, in the process of preparing the coating, the corresponding raw materials are omitted, as follows:

[0229] In this comparative example, the raw material of silica is the Huierte HS-830 silica sol with a particle size of 8 nm to 10 nm.

[0230] Comparative Example 2

[0231] This comparative example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that silica is not used in a compounded manner. Correspondingly, in the process of preparing the coating, the corresponding raw materials are omitted, as follows:

[0232] In this comparative example, the raw material of silica is the Delixin Micro-Nano JA60-40 / 1 silica sol with a particle size of 55 nm to 65 nm.

[0233] Comparative Example 3

[0234] This comparative example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that silica is not used in a compounded manner. Correspondingly, in the process of preparing the coating, the corresponding raw materials are omitted, as follows:

[0235] In this comparative example, the raw material of silica is the Delixin Micro-Nano JA110-40 / 1 silica sol with a particle size of 110 nm to 120 nm.

[0236] Comparative Example 4

[0237] This comparative example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the composition of the compounded silica is different. Correspondingly, in the process of preparing the coating, the corresponding raw materials are omitted, as follows:

[0238] Calculated by the weight percentage of the compounded silica, the compounded silica in this comparative example includes the following components:

[0239] 50% of the first silica with 1 nm ≤ D ≤ 50 nm and

[0240] 50% of the second silica with 50 nm < D ≤ 100 nm;

[0241] Among them, the raw material of the first silica is the Wirth HS-830 silica sol with a particle size of 8 nm to 10 nm; the raw material of the second silica is the Delixin Micro-Nano JA60-40 / 1 silica sol with a particle size of 55 nm to 65 nm.

[0242] Comparative Example 5

[0243] This comparative example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the composition of the compounded silica is different. Correspondingly, in the process of preparing the coating, the corresponding raw materials are omitted, as follows:

[0244] Calculated by weight percentage of the compounded silica, the compounded silica in this comparative example includes the following components:

[0245] The first silica with 1 nm ≤ D ≤ 50 nm is 25%,

[0246] The second silica with 50 nm < D ≤ 100 nm is 25% and

[0247] The fourth silica with 1 μm < D ≤ 3 μm is 50%;

[0248] Among them, the raw material of the first silica is the Wirth HS-830 silica sol with a particle size of 8 nm to 10 nm; the raw material of the second silica is the Delixin Micro-Nano JA60-40 / 1 silica sol with a particle size of 55 nm to 65 nm; the raw material of the fourth silica is the Brofos-silica-B03 particles with a particle size of 1 μm to 3 μm.

[0249] Comparative Example 6

[0250] This comparative example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is that the dosages of some components are different, as follows:

[0251] Calculated by weight percentage, the composition of the aqueous self-lubricating fingerprint-resistant coating shown in this comparative example is as follows:

[0252] Compounded silica 15%,

[0253] Silane coupling agent 8%,

[0254] Potassium fluotitanate 2%,

[0255] Flash rust inhibitor A 1%,

[0256] Anti-scratch additive 2% and

[0257] Water 72%.

[0258] Comparative Example 7

[0259] This comparative example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is the different dosages of some components, which are specifically as follows:

[0260] In terms of weight percentage, the composition of the aqueous self-lubricating fingerprint-resistant coating shown in this comparative example is as follows:

[0261] Compound silica 2%,

[0262] Silane coupling agent 8%,

[0263] Potassium fluotitanate 2%,

[0264] Flash rust inhibitor A 1%,

[0265] Anti-scratch additive 2% and

[0266] Water 85%.

[0267] Comparative Example 8

[0268] This comparative example provides an aqueous self-lubricating fingerprint-resistant coating and its preparation method. The main difference from Example 1 is the different dosages of some components, which are specifically as follows:

[0269] In terms of weight percentage, the composition of the aqueous self-lubricating fingerprint-resistant coating shown in this comparative example is as follows:

[0270] Compound silica 8%,

[0271] Silane coupling agent 3%,

[0272] Potassium fluotitanate 2%,

[0273] Flash rust inhibitor A 1%,

[0274] Anti-scratch additive 2% and

[0275] Water 84%.

[0276] Detection test

[0277] Select 21 galvanized steel plates of the same size and shape (numbered 1 to 21), and use the water-based self-lubricating fingerprint-resistant coatings prepared in Examples 1 to 13 and Comparative Examples 1 to 8 in equal amounts to perform surface passivation treatment on the galvanized steel plates, obtaining 21 groups of galvanized steel plates after surface passivation treatment, with a coating thickness of 1 μm to 2 μm. Then, perform deep drawing treatment through a high-speed deep drawing testing machine and a special mold to prepare deep-drawn workpieces numbered 1 to 21 (wherein, the 1st galvanized steel plate produces the 1st deep-drawn workpiece, the 2nd galvanized steel plate produces the 2nd deep-drawn workpiece... and so on, the 21st galvanized steel plate produces the 1st deep-drawn workpiece). And take the stress deformation area as the processed surface and the unpunched surface as the unprocessed surface. Evaluate the processed surface and the unprocessed surface of the 1st to 21st deep-drawn workpieces using the following methods, and the test results are shown in Table 2 and Figures 1 - 2 。

[0278] 1. Alkaline resistance

[0279] Immerse the processed surface and the unprocessed surface of the deep-drawn workpiece after passivation treatment in a 2% sodium hydroxide solution (w%) at 60 °C for 2 minutes, then rinse with water and dry with air, and observe the surface appearance change with the naked eye. The evaluation criteria are as follows: Grade I: There are no traces on the coating surface; Grade II: There are corrosion white spots visible to the naked eye on the coating surface; Grade III: The coating starts to dissolve or peel off.

[0280] 3. Corrosion resistance

[0281] Perform a salt spray test (JIS Z 2371) on the processed surface and the unprocessed surface of the deep-drawn workpiece. 1. Visually measure the red rust resistance of the processed surface of the deep-drawn workpiece and evaluate the time when the red rust area reaches 5%, in hours; 2. Visually measure the white rust resistance of the unprocessed surface of the deep-drawn workpiece and evaluate the time when the white rust area reaches 5%, in hours.

[0282] 4. Scratch resistance

[0283] Use an HB eraser with a load of 500 g to rub back and forth on the processed surface and the unprocessed surface of the deep-drawn workpiece 10 times, and visually observe and evaluate the surface appearance change. The evaluation criteria are as follows: Grade I: There are no traces on the rubbed part; Grade II: There are traces visible to the naked eye on the rubbed part; Grade III: There are obvious white traces on the rubbed part and cracks appear.

[0284] 5. Glossiness of the deep-drawn processed surface:

[0285] Use a Keshijia WGG60-EJ metal glossiness meter to measure the surface glossiness of the processed surface and the unprocessed surface of the deep-drawn workpiece, with the unit of GU.

[0286] 6. Surface roughness:

[0287] The surface roughness of the processed and unprocessed surfaces of the deep-drawing workpieces was measured using a Kaida NDT110 surface roughness tester, and the Ra data was recorded in μm.

[0288] Table 2 Effect data of the above-mentioned deep-drawing workpieces numbered 1 to 21

[0289]

[0290] Figure 1 Figure for the deep-drawing process after passivating the galvanized steel workpiece with the water-based self-lubricating fingerprint-resistant coating in Example 1 of the present application. It can be seen from Figure 1 that the processed surface after deep drawing is very bright, achieving a bright surface effect, while the unprocessed surface has a matte effect.

[0291] Figure 2 Figure for the deep-drawing process after passivating the galvanized steel workpiece with the water-based self-lubricating fingerprint-resistant coating in Example 2 of the present application. It can be seen from Figure 2 that the processed surface after deep drawing is very bright, achieving a bright surface effect, while the unprocessed surface has a matte effect.

[0292] Combined with Table 2 and Figures 1 - 2It can be seen that, compared with Comparative Examples 1 to 3 that use a single type of silica raw material, Comparative Example 4 only uses nanoscale silica in combination, omitting submicron-scale silica, Comparative Example 5 uses a combination of nanoscale silica and micron-scale silica, Comparative Example 6 uses an excessive amount of combined silica, Comparative Example 7 uses an insufficient amount of combined silica, and Comparative Example 8 uses an insufficient amount of coupling agent. In Examples 1 to 13 of the present application, nanoscale silica and submicron silica are used in combination, along with a coupling agent, compounds of molybdenum, vanadium, titanium, or zirconium, an anti-flash rust agent, an anti-scratch aid, and water. By reasonably controlling the amounts of each component, the comprehensive performance of the prepared waterborne self-lubricating fingerprint-resistant coating is more excellent. When it is applied to the surface of a passivated galvanized steel sheet (see the unprocessed surface for reference), the appearance is good, the coating is continuous, uniform, smooth, flat, without marks (tensile marks, indentations, scratches, friction black lines) and stripes, and it can significantly enhance the alkali resistance, corrosion resistance, and anti-scratch performance of the galvanized steel sheet. Moreover, the fingerprint-resistant coatings of Examples 1 to 13 can make the processed surface of the galvanized steel sheet workpiece extremely bright after deep drawing, and maintain excellent alkali resistance, corrosion resistance, and anti-scratch performance. The inventor speculates that this may be because during the deep drawing process, the grains of the base steel will reorient due to plastic deformation, the grains will elongate, the texture will change, and the grain size is at the micron level (usually the short axis / radial direction is 5 μm to 30 μm, and the long axis is 10 μm to 100 μm). Submicron-scale silica (particle size 100 nm to 1 μm), with a particle size between nanometers and microns, has a very high hardness, and has both certain mechanical grinding ability and chemical activity. Through the deep drawing effect, it can quickly polish the surface of the galvanized steel sheet while maintaining good surface quality, playing a role in medium-precision grinding or polishing; while nanoscale silica (particle size <100 nm) has an extremely small particle size and also has the characteristics of high hardness and wear resistance. Combined with the deep drawing process, it can significantly reduce the surface roughness, flatten the surface, achieve extremely high polishing precision, and reduce the surface roughness of the substrate. In addition, the nanoscale and submicron-scale silica particles can also fill the gaps between large-particle-size particles, such as infiltrating or filling into the micron-scale gaps between metal grains under the deep drawing effect, further reducing the surface roughness of the substrate, achieving higher polishing efficiency and surface quality, and exerting the corrosion resistance of silica, significantly improving the corrosion resistance of the processed surface after deep drawing. By using a coupling agent and other additives in combination, the processed surface of the deep-drawn metal workpiece has a high gloss, a low surface roughness, excellent anti-scratch performance, and both the processed surface and the unprocessed surface maintain excellent corrosion resistance, achieving the purpose of simultaneously polishing and passivating the surface of the substrate processed surface.

[0293] In summary, on the one hand, the water-based self-lubricating fingerprint-resistant coating of the present application can be directly used on the surface of a passivated metal substrate, significantly enhancing the wear resistance, alkali resistance, corrosion resistance, and scratch resistance of the metal substrate (such as galvanized steel sheet), and maintaining a good appearance. On the other hand, it can be used for deep-drawing metal workpieces to achieve the purpose of simultaneously polishing and passivating the surface of the substrate, reducing the surface roughness of the processed surface, significantly improving the gloss, corrosion resistance, and scratch resistance of the processed surface of the workpiece, and broadening the application range of the product to meet different market demands.

[0294] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0295] The above-described embodiments merely represent several implementation manners of the present application, facilitating the specific and detailed understanding of the technical solution of the present application. However, it should not be construed as a limitation on the protection scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning, or limited experiments based on the technical solutions provided in the present application are all within the protection scope of the appended claims of the present application. Therefore, the protection scope of the patent of the present application should be subject to the content of the appended claims, and the specification and drawings can be used to explain the content of the claims.

Claims

1. An aqueous self-lubricating fingerprint-resistant coating, characterized in that, Comprising the following components by weight percentage: Compound silica 5% - 10%, Coupling agent 5% - 12%, Compounds of molybdenum, vanadium, titanium or zirconium 0.1% - 5%, Flash rust inhibitor 0.1% - 2%, Anti - scratching aid 1% - 5% and Water 66% - 88.8%; Wherein, with D representing the particle size, by weight percentage of the compound silica, the compound silica comprises the following components: The first silica with 1nm ≤ D ≤ 50nm 15% - 40%, The second silica with 50nm < D ≤ 100nm 15% - 40% and The third silica with 100nm < D ≤ 1μm 30% - 70%.

2. The water-based self-lubricating fingerprint-resistant coating according to claim 1, wherein, The weight ratio of the first silica, the second silica and the third silica is 1:(0.8 - 1.2):(1.5 - 3).

3. The aqueous self-lubricating fingerprint-resistant coating according to claim 1, wherein By weight percentage of the compound silica, the compound silica comprises the following components: The first silica with 1nm ≤ D ≤ 50nm 15% - 40%, The second silica with 50nm < D ≤ 100nm 15% - 40% and The third silica with 100nm < D ≤ 200nm 30% - 70%.

4. The water-based self-lubricating fingerprint-resistant coating according to claim 1, wherein, The anti - scratching aid is composed of anti - scratching aids with different particle sizes by compounding.

5. The water-based self-lubricating fingerprint-resistant coating according to claim 4, wherein The anti - scratching aid meets one or more of the following (1) - (2): (1) The anti - scratching aid is composed of a first anti - scratching aid with a particle size of 0.1μm - 0.5μm and a second anti - scratching aid with a particle size of 1μm - 3μm according to a weight ratio of 1:(1 - 2); (2) The anti - scratching aid is selected from one or a combination of polyethylene, polytetrafluoroethylene, oxidized polyethylene and silicone dispersions.

6. The water-based self-lubricating fingerprint-resistant paint according to any one of claims 1 to 5, characterized in that The coupling agent includes a combination of one or more of silane coupling agents and titanate coupling agents.

7. The water-based self-lubricating fingerprint-resistant coating according to any one of claims 1 to 5, characterized in that The flash rust inhibitor is selected from one or a combination of organic amine flash rust inhibitors, phosphate flash rust inhibitors, nitrite flash rust inhibitors, silicate flash rust inhibitors, benzoate flash rust inhibitors, organic zinc salt flash rust inhibitors and organic calcium salt flash rust inhibitors.

8. A method for preparing the water-based self-lubricating fingerprint-resistant coating according to any one of claims 1 to 7, characterized in that, Including the following steps: Mix the compound silica, coupling agent, compounds of molybdenum, vanadium, titanium or zirconium, flash rust inhibitor and anti - scratching aid in water.

9. A metal material, characterized in that, At least one surface of the metal material is coated with a coating formed by the aqueous self - lubricating fingerprint - resistant coating according to any one of claims 1 - 7.

10. A deep-drawing workpiece, characterized in that, At least one surface of the deep - drawing workpiece is coated with a coating formed by the aqueous self - lubricating fingerprint - resistant coating according to any one of claims 1 - 7.

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