Anti-pollution items

Abstract

The present invention relates to a pollution prevention article, and more particularly to a pollution prevention article capable of preventing fouling caused by inorganic chlorides.

Description

[Technical Field]

[0001] [Cross-reference to related applications] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0121583 filed on September 26, 2022, and Korean Patent Application No. 10-2023-0129096 filed on September 26, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a pollution prevention article, and more particularly to a pollution prevention article that can prevent fouling caused by inorganic chlorides. [Background technology]

[0003] Anti-fouling coatings are used to prevent the adhesion or adsorption of contaminants to the surfaces of a variety of industrial equipment.

[0004] Chlorine (Cl) dust is generated as a by-product in the process of recycling waste plastic during cement production, and due to recent environmental concerns, a separate chlorine dust treatment facility is being used to extract additional potassium chloride (KCl) from the by-product chlorine dust.

[0005] However, during this chlorine dust treatment process, fouling due to potassium chloride often occurs on the surface of the equipment, and when fouling occurs, the process operation rate is significantly reduced.

[0006] Therefore, for smooth process operation, it is necessary to prevent inorganic chloride contaminants such as potassium chloride from adhering to the inner surfaces of the treatment equipment.

[0007] However, the surface of stainless steel, which is commonly used as the base material for such processing equipment, has high wettability and is prone to adhesion of contaminants due to its characteristics, necessitating periodic cleaning. While methods for preventing the adhesion of contaminants include the application of super-water-repellent or hydrophobic coatings, these coatings still have problems in preventing and removing inorganic chloride contaminants, and the coating layer does not have high durability, resulting in short-lasting effects.

[0008] Therefore, research is needed into anti-fouling coating layers that can prevent inorganic chloride contaminants from adhering to the interior surfaces of devices and can easily be removed even if they do adhere. Summary of the Invention [Problem to be solved by the invention]

[0009] In order to solve the above problems, the present invention provides a stain-proof article including an inorganic chloride stain-proof coating layer. [Means for solving the problem]

[0010] According to one embodiment of the present invention, there is provided a contamination-preventing article comprising: a substrate; and an inorganic chloride contamination-preventing coating layer provided on at least one surface of the substrate, wherein the inorganic chloride contamination-preventing coating layer satisfies the following formulas 1 to 3:

[0011] [Formula 1] 80° <REC<150° [Formula 2] REC / CAH≧2.5 [Formula 3] CAH≧25°

[0012] In the above formulas 1 to 3, REC is the receding contact angle with respect to water (unit: °), CAH is the contact angle hysteresis, which is the difference between the advancing contact angle (unit: °) and the receding contact angle (unit: °) with respect to water. [Effects of the Invention]

[0013] According to the pollution-preventing article of the present invention, fouling caused by inorganic chlorides can be effectively prevented.

[0014] In particular, it can effectively prevent fouling caused by potassium chloride (KCl) adhering to the inner walls of the treatment equipment during the chlorine dust treatment process, which extracts additional potassium chloride (KCl) from chlorine dust, a by-product of recycling waste plastics during cement production. [Brief explanation of the drawings]

[0015] [Figure 1] 2A and 2B are schematic diagrams illustrating a process of forming a salt dome on the surface of an antifouling coating layer according to an embodiment of the present invention; [Figure 2] FIG. 2 is a schematic diagram illustrating a cross section of a salt dome according to an embodiment of the present invention. [Figure 3] 1 is a schematic diagram illustrating a process in which a salt dome is not formed on the surface of a coating layer according to a comparative example of the present invention. [Figure 4] FIG. 2 is a schematic diagram illustrating a process in which a salt dome is not formed on the surface of a substrate according to a comparative example of the present invention. [Figure 5] 1 is a photograph of a salt dome according to one embodiment of the present invention (A) and comparative domes (B, C). DETAILED DESCRIPTION OF THE INVENTION

[0016] In the present invention, terms such as "first" and "second" are used to describe various components, and the terms are used only to distinguish one component from another.

[0017] Furthermore, the terms used in this specification are used only to describe exemplary embodiments and are not intended to limit the present invention.

[0018] Unless otherwise clearly indicated in the context, singular expressions include plural expressions.

[0019] As used herein, terms such as "comprises," "comprises," or "having" are intended to describe embodied features, numbers, steps, components, or combinations thereof, and do not exclude the presence of one or more other features, numbers, steps, components, combinations thereof, or additional possibilities.

[0020] Furthermore, in this specification, when a layer or element is referred to as being formed "on" or "on" another layer or element, it means that the layer or element is formed directly on the other layer or element, or that other layers or elements can be additionally formed between the layers, on the object, or on the substrate.

[0021] While the present invention can be modified in various ways and can take various forms, specific embodiments are illustrated and described in detail below, but it should be understood that the present invention is not limited to the specific disclosed forms, but includes all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention.

[0022] Hereinafter, a contamination prevention article according to one embodiment of the present invention will be described in detail.

[0023] A contamination prevention article according to one embodiment of the present invention includes a substrate; and an inorganic chloride contamination prevention coating layer provided on at least one surface of the substrate, wherein the inorganic chloride contamination prevention coating layer satisfies the following formulas 1 to 3:

[0024] [Formula 1] 80° <REC<150° [Formula 2] REC / CAH≧2.5 [Formula 3] CAH≧25°

[0025] In the above formulas 1 to 3, REC is the receding contact angle (unit: °) with respect to water, CAH is the contact angle hysteresis, which is the difference between the advancing contact angle (unit: °) and the receding contact angle (unit: °) with respect to water.

[0026] As used herein, the term "contact angle" refers to the angle between the gas / liquid interface of a liquid droplet placed on a solid surface and the solid surface. Such contact angles can be measured by various methods, and in this specification, the contact angle of a liquid droplet was measured by the Sessile Drop Method using a commercial contact angle measuring device (KRUSS, Model: DSA-100).

[0027] The contact angle is a measure of the wettability of a surface, and a low contact angle can be considered to indicate high wettability, and a high contact angle can be considered to indicate low wettability.

[0028] In addition, the term "advancing contact angle" used herein refers to the maximum contact angle that can be formed without the contact line between the droplet and the surface moving. In actual measurements, it is defined as the contact angle at which the contact line of the droplet begins to move while continuously adding small amounts of water.

[0029] In addition, the term "receding contact angle" used herein refers to the minimum contact angle that can be formed without the contact line between the droplet and the surface moving. In actual measurement, the receding contact angle can be measured as the angle just before the three-phase (solid / liquid / gas) interface moves as the amount of water is gradually reduced through the needle of the syringe into which the water has been injected.

[0030] In this specification, the advancing contact angle and receding contact angle were measured using a water droplet at atmospheric pressure (1 atm) and 25°C.

[0031] Also, the term "CAH" used herein refers to contact angle hysteresis, which is the difference between the advancing contact angle and the receding contact angle measured as described above.

[0032] The present inventors have been researching methods for preventing the adhesion of contaminants, particularly inorganic chlorides, to the surface of a substrate or coating layer, and have discovered that when the contact angle of the surface satisfies certain conditions, it is possible to effectively prevent the adhesion of inorganic chloride contaminants while maintaining excellent coating durability, which led to the completion of the present invention.

[0033] More specifically, when the surface of the coating layer satisfies the contact angle requirement of one embodiment of the present invention, even if a solution containing an inorganic chloride such as potassium chloride (KCl) is applied to the surface of the coating layer, it is found to dry in a dome-like shape with a hollow interior and a minimized contact area with the surface of the coating layer. This prevents fouling caused by inorganic chlorides, and the dome shape is maintained even after drying, allowing for easy removal of contaminants.

[0034] Furthermore, it was confirmed that a dome is not formed or maintained simply because the coating layer surface is hydrophobic or the contact angle is high, but rather that a dome is formed during drying only when the backward contact angle, contact angle history, and ratio of the backward contact angle to the contact angle history in Equations 1 to 3 according to one embodiment of the present invention satisfy certain conditions.

[0035] For example, the inorganic chloride anti-fouling coating layer of the present invention satisfies all of the following formulas 1 to 3.

[0036] [Formula 1] 80° <REC<150° [Formula 2] REC / CAH≧2.5 [Formula 3] CAH≧25°

[0037] In the above formulas 1 to 3, REC is the receding contact angle (unit: °) with respect to water, CAH is the contact angle hysteresis, which is the difference between the advancing contact angle (unit: °) and the receding contact angle (unit: °) with respect to water.

[0038] An inorganic chloride antifouling coating layer according to one embodiment of the present invention satisfies the above formula 1. That is, the receding contact angle (REC) may be greater than 80°, or 85° or more, or 90° or more, 95° or more, or 100° or more, but less than 150°, or 145° or less, or 140° or less, or 135° or less, or 130° or less.

[0039] Furthermore, the inorganic chloride antifouling coating layer according to one embodiment of the present invention satisfies the above formula 2. That is, the ratio of the backward contact angle to the contact angle hysteresis (REC / CAH) may be 2.5 or more, or 2.8 or more, or 3.0 or more, or 3.1 or more, or 3.2 or more, and may be 10 or less, or 9 or less, or 8 or less, or 7 or less, or 6 or less, or 5 or less, or 4 or less, or 3.5 or less.

[0040] Furthermore, the inorganic chloride antifouling coating layer according to one embodiment of the present invention satisfies the above formula 3. That is, the contact angle history (CAH) may be 25° or more, or 26° or more, or 28° or more, and 60° or less, or 50° or less, or 40° or less, or 35° or less, or 32° or less.

[0041] In one embodiment of the present invention, the substrate may be, but is not limited to, stainless steel such as SUS or STS, or glass.

[0042] FIG. 1 is a schematic diagram illustrating a process of forming a salt dome on the surface of a coating layer according to an embodiment of the present invention.

[0043] According to one embodiment of the present invention, when the receding contact angle, contact angle history, and ratio of the receding contact angle to the contact angle history satisfy the conditions of Equations 1 to 3, an inorganic chloride solution is applied to the surface of the coating layer, forming droplets, and then drying.

[0044] 1, first, as the droplets of inorganic chloride solution attached to the surface of the coating layer dry, solid salt is generated from the edges along the boundary between the droplets and the air. As the droplets continue to dry, the salt continues to grow along the droplet's boundary, and the droplets remaining inside are absorbed into the salt dome and evaporate to the outside, eventually forming a salt dome with an empty center.

[0045] On the other hand, when certain conditions of Equations 1 to 3 according to one embodiment of the present invention are satisfied, the formed salt dome maintains its shape on a flat surface, but when the surface is tilted, for example, at an angle of about 45 degrees, it easily falls off without a strong external force, leaving no residue and making it very easy to remove.

[0046] The inorganic chloride contamination-resistant coating layer of the present invention is not limited to a coating layer of a specific component, and as long as the coating layer simultaneously satisfies formulas 1 to 3, it can exhibit the effect of being easily removed by forming a salt dome on the coating layer surface during the deposition and drying process of chlorides, regardless of the structure, components, manufacturing method, etc. of the coating layer.

[0047] If the backward contact angle (REC) with water is 80° or less, the salt or solution inside the droplet tends to remain in contact with the coating layer rather than moving to the outer periphery, which can result in salt components remaining on the surface of the coating layer during drying. On the other hand, if the REC is too high, above 150°, the droplet dries in an almost spherical shape, and the solution inside the droplet continues to move to the outer periphery rather than the solution near the surface, which evaporates during the latter half of drying. As a result, salt remains in the part of the droplet that comes into contact with the surface, which can prevent the formation of a salt dome.

[0048] In addition, if the contact angle hysteresis (CAH) is less than 25°, the interface between the droplet and the surface in the salt dome is not fixed and tends to move freely, which allows the droplet interface to gradually move into the salt dome as the droplet dries. As a result, the size of the dome itself gradually decreases during the drying process, becoming solidified and unable to maintain its shape.

[0049] Therefore, in order for the salt dome shape to be maintained without any residual salt on the surface of the coating layer, the REC and CAH must each be high enough to meet certain standards. However, if the ratio of CAH to REC is too high, the salt dome shape may collapse during the drying process, ultimately making it difficult to maintain the salt dome shape after drying.

[0050] Therefore, the ratio of REC to CAH is also important for the formation and maintenance of the salt dome. When the conditions of Equations 1 to 3 are simultaneously satisfied, the salt dome shape can be maintained during the drying process of the droplets, and no salt components can remain on the surface of the coating layer.

[0051] Figure 2 is a schematic diagram of a cross section of a salt dome according to one embodiment of the present invention, where Ro is the outer radius of the salt dome, Ri is the inner radius of the salt dome, and h is the height of the salt dome.

[0052] Referring to Figure 2, the ratio of the dome height to the outer radius (Ro) of the salt dome is 0.5 or more (h / Ro≧0.5), and the open space area at the contact surface between the salt dome and the surface is 50% or more (Ri 2 / Ro 2 ≧0.5), it can be considered that a salt dome as defined in the present invention has been formed.

[0053] In contrast, FIG. 3 is a schematic diagram showing a process in which a salt dome is not formed on the surface of a coating layer according to a comparative example of the present invention, and FIG. 4 is a schematic diagram showing a process in which a salt dome is not formed on the surface of a substrate according to a comparative example of the present invention.

[0054] 3, initially, as droplets of inorganic chloride solution attached to the surface of a coating layer dry, salt is generated from the edge along the boundary between the droplet and air, as in the present invention. However, if one or more of the conditions of Equations 1 to 3 according to an embodiment of the present invention are not met, the droplets continue to dry, and a salt dome does not form, resulting in an incomplete dome, or the dome shape collapses, leaving the salt components irregularly attached to the surface.

[0055] Referring to FIG. 4, when droplets of an inorganic chloride solution are applied to a surface with a low contact angle, such as a SUS coating, salts generated during the drying process do not form a dome shape but spread over the entire surface and adhere strongly, making them difficult to remove and causing fouling.

[0056] FIG. 5 is a photograph of a salt dome according to one embodiment of the present invention (A) and comparative domes (B, C).

[0057] In Figure 5, (A) is a photograph of a perfectly formed salt dome peeled off from the surface according to one embodiment of the present invention, (B) is a photograph of an incompletely formed dome, and (C) is a photograph of chloride that has spread and adhered to the surface without the dome forming.

[0058] An example of an inorganic chloride contamination prevention coating layer that satisfies the above characteristics may include, but is not limited to, a first coating layer including a cured product of alkyl-trialkoxysilane and tetraalkoxysilane; and a second coating layer formed on the first coating layer and including a cured product of fluorinated polyether silane.

[0059] The alkyl-trialkoxysilane may be a compound represented by the following formula 1:

[0060] [Chemical formula 1] R 11 -Si(R 12 )(R 13 )(R14 )

[0061] In the above chemical formula 1, R 11 is an alkyl group having 1 to 5 carbon atoms, R 12 ~R 14 are each independently an alkoxy group having 1 to 5 carbon atoms.

[0062] According to one embodiment of the present invention, the tetraalkoxysilane may be a compound represented by the following Chemical Formula 2:

[0063] [Chemical formula 2] Si(R 21 )(R 22 )(R 23 )(R 24 )

[0064] In the above chemical formula 2, R 21 ~R 24 are each independently an alkoxy group having 1 to 5 carbon atoms.

[0065] According to one embodiment of the present invention, the first coating liquid may contain 1 to 50 parts by weight of tetraalkoxysilane with respect to 100 parts by weight of alkyl-trialkoxysilane.

[0066] According to one embodiment of the present invention, the first coating liquid may contain 1 to 10 parts by weight of an organic acid relative to 100 parts by weight of an alkyl-trialkoxysilane.

[0067] According to one embodiment of the present invention, the fluorinated polyether silane may be a compound containing a moiety represented by the following chemical formulas 3-1 to 3-4.

[0068] [Chemical formula 3-1] CF3- [Chemical formula 3-2] -CF2-CF2-O- [Chemical formula 3-3] -CF2-CF2-CF2-O- [Chemical formula 3-4] -Si(R 31 )(R 32 )(R 33 )

[0069] In the above chemical formula 3-4, R 31 ~R 33 are each independently an alkoxy group having 1 to 5 carbon atoms.

[0070] According to one embodiment of the present invention, the first coating liquid and the second coating liquid can be cured independently at a temperature of 100 to 150°C.

[0071] According to one embodiment of the present invention, the cured thickness of the first coating layer may be about 0.1 to about 100 μm, more preferably about 1 to about 50 μm, or about 2 to about 10 μm. When the cured thickness of the first coating layer is within the above range, it is possible to prevent cracking while exhibiting an appropriate coating hardness.

[0072] The cured thickness of the second coating layer may be about 1 to about 100 nm, or about 5 to about 50 nm. Specifically, the second coating layer may be formed by applying the fluorinated polyether silane contained in the second coating liquid as a mono-molecule layer. When the cured thickness of the second coating layer is within the above range, a uniform coating layer and an appropriate surface energy level can be maintained.

[0073] According to one aspect of the present invention, the optical film can be formed by a method including the steps of: applying a first coating liquid containing an alkyl-trialkoxysilane, a tetraalkoxysilane, and an organic acid; curing the applied first coating liquid to form a first coating layer; applying a second coating liquid containing a fluorinated polyether silane on the first coating layer; and curing the applied second coating liquid to form a second coating layer.

[0074] In a method according to one embodiment of the present invention, first, a first coating liquid containing an alkyl-trialkoxysilane, a tetraalkoxysilane, and an organic acid is applied to a surface of a substrate.

[0075] According to one embodiment of the present invention, the alkyl-trialkoxysilane may be a compound represented by the following Chemical Formula 1:

[0076] [Chemical formula 1] R 11 -Si(R 12 )(R 13 )(R 14 )

[0077] In the above chemical formula 1, R 11 is an alkyl group having 1 to 5 carbon atoms, R 12 ~R 14 are each independently an alkoxy group having 1 to 5 carbon atoms.

[0078] More specifically, the R 11 may be methyl, ethyl, propyl, butyl, or pentyl and may be straight or branched chain.

[0079] R 12 ~R 14 may each independently be methoxy, ethoxy, propoxy, butoxy, or pentoxy, and may be straight or branched chain.

[0080] Specifically, for example, the alkyl-trialkoxysilane may be at least one selected from the group consisting of methyl-trimethoxysilane, methyl-triethoxysilane, methyl-tripropoxysilane, methyl-tributoxysilane, methyl-tripentoxysilane, ethyl-trimethoxysilane, ethyl-triethoxysilane, ethyl-trippropoxysilane, ethyl-tributoxysilane, ethyl-tripentoxysilane, propyl-trimethoxysilane, propyl-triethoxysilane, propyl-trippropoxysilane, propyl-tributoxysilane, propyl-tripentoxysilane, butyl-trimethoxysilane, butyl-triethoxysilane, butyl-trippropoxysilane, butyl-tributoxysilane, butyl-tripentoxysilane, pentyl-trimethoxysilane, pentyl-triethoxysilane, pentyl-trippropoxysilane, pentyl-tributoxysilane, and pentyl-tripentoxysilane.

[0081] The alkyl-trialkoxysilane is a component that forms the main network of the inorganic coating through a sol-gel reaction within the composition. The alkyl group increases the flexibility of the network structure, alleviating stress that occurs during reactions between silanols or between silanols and the metal oxide layer on the substrate surface. When using only alkylsilane, the number of silanols participating in the reaction is low, making it difficult to reduce surface energy during subsequent fluorine coating. When using only alkoxysilane, the aforementioned stress relief effect may be difficult to achieve.

[0082] According to one embodiment of the present invention, the tetraalkoxysilane may be a compound represented by the following Chemical Formula 2:

[0083] [Chemical formula 2] Si(R 21 )(R 22 )(R 23 )(R 24 )

[0084] In the above chemical formula 2, R 21 ~R 24 are each independently an alkoxy group having 1 to 5 carbon atoms.

[0085] More specifically, R 21 ~R 24 may each independently be methoxy, ethoxy, propoxy, butoxy, or pentoxy, and may be straight or branched chain.

[0086] Specifically, for example, the tetraalkoxysilane may be at least one selected from the group consisting of tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, and tetrapentoxysilane.

[0087] The tetraalkoxysilane can increase the number of silanol groups in the composition that can participate in reactions between silanols or between silanols and metal oxide layers on the substrate surface, which subsequently increases the reactivity with fluorosilanes and helps to achieve a surface with low surface energy.

[0088] By mixing alkyl-trialkoxysilane and tetraalkoxysilane in the appropriate ratio, it is possible to prevent the problem of cracks occurring in the entire coating layer network and to provide an appropriate amount of silanol reactive groups on the surface.

[0089] According to one embodiment of the invention, the organic acid may be a carboxylic acid having 1 to 5 carbon atoms.

[0090] Specifically, for example, the organic acid may be one or more selected from the group consisting of formic acid, acetic acid, and propionic acid.

[0091] The organic acids mentioned above act as catalysts to promote the hydrolysis of silane groups within the composition and can determine the overall network structure. Under low pH acidic conditions, the hydrolysis rate is faster than the condensation reaction rate, resulting in the formation of a linear structure through silane bonds. Conversely, under basic conditions, the condensation reaction rate is even faster, resulting in the formation of a particulate structure. While inorganic acids such as hydrochloric acid can also be used, organic acids are more useful for controlling gel time.

[0092] According to one embodiment of the present invention, the first coating liquid may contain about 1 to about 50 parts by weight of tetraalkoxysilane based on 100 parts by weight of alkyl-trialkoxysilane.

[0093] The use of tetraalkoxysilane in the above weight parts can be advantageous in achieving suitable surface energy and excellent adhesion.

[0094] According to one embodiment of the present invention, the first coating liquid may contain about 1 to about 10 parts by weight of an organic acid based on 100 parts by weight of an alkyl-trialkoxysilane.

[0095] By using the organic acid in the above-mentioned weight parts, a linear network structure can be obtained at an appropriate hydrolysis rate, and the mechanical properties of the coating layer can be maintained.

[0096] The pH of the first coating liquid may be about 7 or less, or about 5 or less, or about 3 or less, or may be about 1 or more, or about 2 or more.

[0097] The pH can affect the rate of hydrolysis and the rate of condensation reaction, and the difference in the rate of these two reactions determines the structure of the coating film and affects the storage stability of the produced coating solution.

[0098] From this perspective, a stable inorganic coating film can be obtained under acidic conditions having a pH in the aforementioned range.

[0099] The first coating liquid may further contain an organic solvent in addition to the above-mentioned components. Specific examples of such organic solvents include alcohols and ethers, and the amount of the organic solvent may be appropriately selected in consideration of coating properties and drying after application.

[0100] When the first coating solution is applied to the substrate surface, the coating thickness may be about 0.1 to about 100 μm, more preferably about 1 to about 50 μm, or about 2 to about 10 μm, based on the thickness after drying and curing. When the cured thickness of the first coating layer is within the above range, it is possible to prevent cracking while exhibiting appropriate coating hardness.

[0101] The application method is not particularly limited, and a method commonly used in the technical field to which the present invention pertains can be selected, such as directly applying with a tool such as a brush, spraying after appropriately adjusting the viscosity, or coating with a bar.

[0102] After application, drying can be carried out at room temperature for about 10 minutes to about 1 hour. The drying conditions may vary depending on the type and amount of the solvent used.

[0103] After drying, curing can be carried out at a temperature of about 100 to about 150° C. for about 30 minutes to about 2 hours.

[0104] In the curing process, a sol-gel reaction of the alkyl-trialkoxysilane in the first coating liquid and the silane group in the tetraalkoxysilane compound occurs to form the first coating layer.

[0105] According to one embodiment of the present invention, the fluorinated polyether silane may be a compound containing a moiety represented by the following chemical formulas 3-1 to 3-4.

[0106] [Chemical formula 3-1] CF3- [Chemical formula 3-2] -CF2-CF2-O- [Chemical formula 3-3] -CF2-CF2-CF2-O- [Chemical formula 3-4] -Si(R 31 )(R 32 )(R 33 )

[0107] In the above chemical formula 3-4, R 31 ~R 33 are each independently an alkoxy group having 1 to 5 carbon atoms.

[0108] The fluorinated polyether silane is a compound having a fluorinated carbon at one end, an alkoxysilane group at the other end, and a fluorinated ethoxy or fluorinated propoxy group in the middle, and can form a hard coating layer by directly forming a covalent bond with the first coating layer, and can significantly reduce the surface energy of the coating layer due to the large amount of fluorine chains.

[0109] In the second coating liquid, the fluorinated polyether silane can be used together with an alkoxy fluorinated alkyl solvent.

[0110] The alkoxy fluorinated alkyl solvent used herein may be an ether compound represented by the following chemical formula 4:

[0111] CF3-(CF2) n -O-(CH2) m -CH3

[0112] In the above chemical formula, n and m may each independently be an integer of 1 to 5.

[0113] The ether compound has an alkyl group with no fluorine atoms attached to one side of the oxygen atom at the center, and an alkyl group in which all hydrogen atoms are substituted with fluorine atoms attached to the other side.

[0114] Such an ether compound has excellent compatibility with the above-mentioned fluorinated polyether silane compound, and can disperse the fluorinated polyether silane compound uniformly in the second coating liquid.

[0115] When the second coating liquid is applied to the substrate surface on which the first coating layer is formed, the coating thickness may be about 1 to about 100 nm based on the thickness after drying and curing. Specifically, the second coating layer may be in a state in which the fluorinated polyether silane contained in the second coating liquid is applied as a mono-molecule layer. When the cured thickness of the second coating layer is within this range, a uniform coating layer and an appropriate surface energy level can be maintained.

[0116] The application method is not particularly limited, and a method commonly used in the technical field to which the present invention pertains can be selected, such as directly applying with a tool such as a brush, spraying after appropriately adjusting the viscosity, or coating with a bar.

[0117] After application, drying can be carried out at room temperature for about 10 minutes to about 1 hour. The drying conditions may vary depending on the type and amount of the solvent used.

[0118] After drying, curing can be carried out at a temperature of about 100 to about 150° C. for about 30 minutes to about 2 hours.

[0119] During the curing process, the fluorinated polyether silane in the second coating liquid interacts with the functional groups contained in the first coating layer to form a second coating layer.

[0120] According to one embodiment of the invention, the first coating layer may have a cured thickness of about 0.1 to about 100 μm.

[0121] The second coating layer may have a cured thickness of about 1 to about 100 nm.

[0122] The inorganic chloride anti-fouling coating layer provided according to one embodiment of the present invention satisfies the above-mentioned formulas 1 to 3, and when droplets of an inorganic chloride solution are attached, a salt dome shape is formed. Such a salt dome is easy to remove and can block the occurrence of surface contamination and fouling caused by inorganic chlorides, thereby providing a variety of articles with excellent anti-fouling effects.

[0123] The functions and effects of the present invention will be described in more detail below through specific examples of the invention. However, these examples are presented only as examples of the invention and do not define the scope of the invention. [Example]

[0124] <Example> Example 1 First coating liquid Five parts by weight of methyltrimethoxysilane was used as the alkyltrialkoxysilane component, one part by weight of tetraethoxysilane was used as the tetraalkoxysilane component, and four parts by weight of a 6 wt% acetic acid solution diluted in water was used as the organic acid component, and these were mixed (pH approximately 2.3).

[0125] 100 parts by weight of the coating liquid was diluted with about 50 parts by weight of isopropyl alcohol as a solvent to prepare a first coating liquid.

[0126] Second coating liquid As the fluorinated polyether silane component, Optool-DSX, a perfluoropolyether silane manufactured by Daikin Corporation, was dissolved in Novec-7200 manufactured by 3M Corporation as a solvent at a concentration of 1 wt % and used.

[0127] Formation of inorganic chloride anti-fouling coating layer The first coating solution was applied to the surface of a stainless steel substrate (Stainless steel 316, 10 cm x 10 cm) using a brush, dried at room temperature for about 30 minutes, and then cured at a temperature of about 130°C for about 1 hour to form a first coating layer with a thickness of about 5 μm.

[0128] The second coating solution was again applied thereto using a brush, dried at room temperature for about 30 minutes, and then cured at a temperature of about 130° C. for about 1 hour to form a second coating layer with a thickness of about 10 nm.

[0129] Example 2 An inorganic chloride contamination resistant coating layer was formed in the same manner as in Example 1, except that the second coating solution used was a solution of Optool-DSX, a perfluoropolyether silane from Daikin, dissolved in Novec-7200 from 3M as a solvent at a concentration of 0.1 wt%.

[0130] Comparative Example 1 Comparative Example 1 was prepared by using only the substrate made of the same stainless steel material as in Example 1.

[0131] Comparative Example 2 After thoroughly cleaning the slide glass with isopropyl alcohol and acetone and completely drying it, 20 cst silicone oil (DMS-T12, Gelest) was applied to the front of the slide glass using a brush. The slide glass was then placed vertically for about an hour to remove excess oil from the surface, and then reacted at 130°C for 24 hours. After the reaction, the remaining silicone oil was washed away with isopropyl alcohol and acetone.

[0132] Comparative Example 3 Using a Sylgard 184 Elastomer Kit (Dow Corning), 10 parts by weight of base and 1 part by weight of curing agent were mixed, and after removing air bubbles, the mixture was poured into a Petri dish to a thickness of 5 mm and cured in an oven at 70°C for 3 hours.

[0133] Comparative Example 4 A super-water-repellent coating was produced using Neverwet Spray (Rust-Oleum Corporation), a commercial super-water-repellent coating product. The Neverwet Base Coating was applied to the SUS substrate as a first coat and then dried at room temperature for 1 hour. The Neverwet Top Coating was applied on top of the first coat and then dried at 70°C for 1 hour.

[0134] Comparative Example 5 The S.PDMS1 solution according to Example 7 of Korean Patent Publication No. 2015-0033725 was prepared and coated onto a stainless steel substrate (Stainless steel 316, 10 cm x 10 cm), and then cured at 120°C for 3 hours.

[0135] Comparative Example 6 90.9 parts by weight of Dow's Sylgard 184 silicone elastomer kit base resin and 9.1 parts by weight of Dow's Sylgard 184 silicone elastomer kit crosslinker were mixed and air bubbles were removed. The mixture was applied to the surface of a stainless steel substrate (Stainless steel 316, 10 cm x 10 cm) and cured at 120°C for 3 hours.

[0136] Comparative Example 7 45 parts by weight of Dow's Sylgard 184 silicone elastomer kit base resin, 4.5 parts by weight of Dow's Sylgard 184 silicone elastomer kit crosslinker, and 50.5 parts by weight of silicone oil (Gelest, product name: DMS-T11) were mixed and air bubbles were removed. The mixture was applied to the surface of a stainless steel substrate (Stainless steel 316, 10 cm x 10 cm) and cured at 120°C for 3 hours.

[0137] Comparative Example 8 The sample prepared in Comparative Example 7 was immersed in DMS-T11 (Mw: 1,250 g / mol) silicone oil at room temperature for 24 hours, then removed and placed upright to remove residual oil from the surface for 30 minutes.

[0138] [Table 1]

[0139] In Table 1, ADV is the advancing contact angle (unit: °) with water at a temperature of 25°C, REC is the receding contact angle (unit: °) with water at a temperature of 25°C, and CAH is the contact angle hysteresis, which is the difference between the advancing contact angle (unit: °) and the receding contact angle (unit: °) with water at a temperature of 25°C.

[0140] <Experimental Example> (1) Presence or absence of salt dome formation 400g of KCl (99.0%, Tokuyama Pharmaceutical Co., Ltd.) was completely dissolved in 1kg of distilled water at 80°C, then cooled to room temperature (25°C). The remaining solution, after which KCl precipitated, was used as a saturated KCl solution. To evaluate the KCl salt dome, 50μL of saturated KCl solution was dropped onto 10 different points on the sample surface using a pipette. After drying in an oven at 60°C for 12 hours, the salt dome morphology was confirmed.

[0141] After drying, the ratio of the dome height to the outer radius (Ro) must be 0.5 or more (h / Ro≧0.5) and the area of ​​open space at the contact surface between the salt dome and the surface must be 50% or more (Ri 2 / Ro 2 ≧0.5) to observe whether a salt dome formed.

[0142] The cases where a salt dome that satisfied the above conditions was formed were evaluated as O, and the cases where a dome was formed but an incomplete salt dome that did not satisfy the above conditions was formed, or where chlorides spread and adhered to the surface without a dome shape were evaluated as X.

[0143] (2) Presence or absence of salt dome or chloride deposits After observing the formation of salt domes (1), the surface was tilted so that the angle between the surface and the ground was 45°. The number of salt domes (or chloride deposits if no salt domes were formed) that fell off the surface was counted and evaluated as follows:

[0144] O: Four or more salt domes or deposits △: Salt dome or deposits are present in 1 to 3 spots or less X: The salt dome or all of the deposits fall off.

[0145] (3)Residues After evaluating whether or not salt domes had adhered in (2), if there was no residue visible to the naked eye on the surface of the salt dome or the area where the adhesion had fallen off, it was rated as X, and if there was residue remaining, it was rated as O.

[0146] (4) Scratch resistance For the coating layer surfaces of the Examples and Comparative Examples, potassium chloride was applied between the two substrate surfaces by unit area (cm 2 After increasing 0.1g per 2 The load was applied and the sample was subjected to 100 reciprocating movements of 1 cm. After the scratch test, if no scratches were observed with the naked eye on the surface, the sample was evaluated as O, and if scratches were observed, the sample was evaluated as X.

[0147] [Table 2]

[0148] Referring to Table 2, in Examples 1 and 2, where the coating layer surface satisfies all of the prescribed formulas 1 to 3, salt domes were formed as the chlorides attached to the surface dried, and the formed salt domes easily fell off without excessive external force, leaving no residue, and it was evaluated that the effect of preventing contamination by chlorides was very excellent.

[0149] On the other hand, in the comparative examples that did not satisfy at least one of the formulas 1 to 3, no salt dome was formed under the same conditions as the examples (Comparative Examples 1 to 8), or deposits remained on the surface (Comparative Examples 1, 4 to 8), and there was almost no effect in preventing contamination by chlorides.

Claims

1. a substrate; and an inorganic chloride anti-fouling coating layer provided on at least one surface of the substrate; The inorganic chloride anti-fouling coating layer satisfies the following formulas 1 to 3, [Formula 1] 80°<REC<150° [Formula 2] REC / CAH≧2.5 [Formula 3] CAH≧25° In the above formulas 1 to 3, REC is the receding contact angle (unit: °) with respect to water; CAH is the contact angle hysteresis, which is the difference between the advancing contact angle (unit: °) and the receding contact angle (unit: °) with respect to water; The inorganic chloride antifouling coating layer is a first coating layer comprising a cured product of an alkyl-trialkoxysilane and a tetraalkoxysilane; and a second coating layer formed on the first coating layer and including a cured product of a fluorinated polyether silane; Anti-pollution items.

2. The contamination prevention article according to claim 1 , wherein REC / CAH in formula 2 is 10 or less.

3. 2. The contamination control article of claim 1, wherein REC in Formula 1 is 85° or greater.

4. 2. The contamination control article of claim 1, wherein CAH in Formula 3 is 60° or less.

5. 10. The contamination control article of claim 1, wherein the inorganic chloride comprises potassium chloride (KCl).

6. The contamination prevention article according to claim 1, wherein the alkyl-trialkoxysilane is a compound represented by the following chemical formula 1: [Chemical formula 1] R １１ -Si(R １２ )(R １３ )(R １４ ) In the above chemical formula 1, R １１ is an alkyl group having 1 to 5 carbon atoms, R １２ ~R １４ are each independently an alkoxy group having 1 to 5 carbon atoms.

7. The contamination prevention article according to claim 1, wherein the tetraalkoxysilane is a compound represented by the following chemical formula 2: [Chemical formula 2] Si(R ２１ )(R ２２ )(R ２３ )(R ２４ ) In the above chemical formula 2, R ２１ ~R ２４ are each independently an alkoxy group having 1 to 5 carbon atoms.

8. The contamination prevention article according to claim 1, wherein the fluorinated polyether silane is a compound containing a group represented by the following chemical formulas 3-1 to 3-4: [Chemical formula 3-1] CF ３ - [Chemical formula 3-2] -CF ２ -CF ２ -O- [Chemical formula 3-3] -CF ２ -CF ２ -CF ２ -O- [Chemical formula 3-4] -Si(R ３１ )(R ３２ )(R ３３ ) In the above chemical formula 3-4, R ３１ ~R ３３ are each independently an alkoxy group having 1 to 5 carbon atoms.

9. The pollution control article of claim 1 , wherein the substrate is stainless steel.

Images