Water sliding film, and article having water sliding film on surface

Abstract

The present invention is a water slide film (10) that can maintain a constant or higher slip property after a weather resistance test and a salt water spray test, the water slide film (10) comprising: a base layer (14) formed on a glass substrate (12), and a lubricating layer (16) held by the base layer (14), the base layer (14) being obtained by modifying a reactive functional group on the surface of the glass substrate (12), the lubricating layer (16) being composed of a polymer containing a reactive functional group that can covalently bond with the reactive functional group of the base layer (14), a part of the reactive functional group of the base layer (14) covalently bonding with a part of the reactive functional group of the lubricating layer (16). In addition, the base layer (14) contains a cyclic conjugated functional group modified on the surface of the glass substrate (12), the lubricating layer (16) contains a polymer having a hydrogen atom with a charge of δ + , and a part of the cyclic conjugated functional group of the base layer (14) interacts with a part of the hydrogen atom with a charge of δ + of the lubricating layer (16) via π electron interaction.

Description

[0001] Related applications

[0002] This application claims priority to Japanese Patent Application No. 2021-122645, filed on July 27, 2021, which is incorporated herein by reference. Technical Field

[0003] The present invention relates to a hydrophobic film formed by a base layer and a lubricating layer held by the base layer, and an article having a surface covered therewith. Background Technology

[0004] To achieve non-wetting properties (slippage characteristics) to liquids, there is a concept of forming a lubricating film on the surface of an article. In the prior art, to prevent the lubricating fluid from flowing out, it is necessary to pre-form a microporous structure on the surface of the article, which retains the lubricating fluid.

[0005] In contrast, the lubricating film of Patent Document 1 has the following characteristics: the base layer retains the lubricant by utilizing π-electron interactions, thus eliminating the need to form a microporous structure on the surface of the article, and is of great interest in imparting slip properties to flat surfaces.

[0006] Furthermore, in recent years, with the development of image processing technology and the miniaturization of cameras and lenses, the adhesion characteristics of water droplets at small image collection ports have received attention. Current evaluations of water droplet adhesion characteristics are mostly based on visual observation, using water droplets or liquids larger than 10 μl that can be easily formed by a dropper. However, it is known that very small droplets have a significant impact on visibility. This is because the smaller the droplet, the greater the adhesion due to even slight surface depressions and dirt.

[0007] Patent Document 1 evaluates the slip characteristics using water droplets of 10 μl or more, but does not evaluate droplets smaller than 10 μl. Furthermore, Patent Document 1 also reports that 5 μl droplets become difficult to slip off due to the unevenness of the surface, hindering their movement. Therefore, the inventors have established a method for forming a surface where droplets of 4 μl or less (diameter φ = 2 mm or less) can also slip off.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent No. 6678018 Summary of the Invention

[0011] The problem the invention aims to solve

[0012] The inventors promoted the practical application of the synovial membrane described in Patent Document 1. However, the synovial membrane in Patent Document 1 has the following problems: after 120 hours of weather resistance test and 240 hours of salt spray resistance test, it cannot maintain the slippage characteristics (non-slippage) of water droplets with a diameter of 1 to 2.5 mm.

[0013] The object of the present invention is to provide a hydrophobic film formed by a base layer formed on a substrate and a lubricating layer held by the base layer, which maintains a constant or higher slip characteristics after weather resistance test and salt spray resistance test.

[0014] Solution for solving the problem

[0015] To address the aforementioned issues, the inventors conducted in-depth research and discovered that by modifying the surface of a substrate with reactive functional groups as a base layer, and using a polymer containing reactive functional groups covalently bonded to these reactive functional groups to form a lubricating layer, a portion of the reactive functional groups in the base layer covalently bonds with a portion of the reactive functional groups in the lubricating layer. After weather resistance tests and salt spray tests, the slip characteristics remain constant or higher, thus completing the present invention.

[0016] That is, the hydrophobic membrane of the present invention comprises:

[0017] A base layer formed on a substrate, and a lubricating layer held by the base layer.

[0018] The aforementioned base layer is obtained by modifying the surface of the aforementioned substrate with reactive functional groups.

[0019] The aforementioned lubricating layer is composed of a polymer containing reactive functional groups, which can covalently bond with the reactive functional groups of the aforementioned base layer.

[0020] A portion of the reactive functional groups in the aforementioned base layer covalently bonds with a portion of the reactive functional groups in the aforementioned lubricating layer.

[0021] In addition, the aforementioned base layer contains cyclic conjugated functional groups modified on the surface of the aforementioned substrate.

[0022] The aforementioned lubricating layer contains a charge of δ + High molecules with hydrogen atoms

[0023] A portion of the cyclic conjugated functional groups in the aforementioned base layer and the aforementioned lubricating layer have a charge of δ. + A portion of the hydrogen atoms undergo π-electron interactions.

[0024] Here, "reactive functional group" is preferably selected from at least one functional group in the group consisting of carbon-carbon double bonds, carboxyl groups, amino groups, hydroxyl groups, and epoxy groups. Furthermore, "covalent bonding" also includes polymerization reactions, copolymerization reactions, cross-linking structures, grafting structures, etc. Additionally, "cyclic conjugated functional group" refers to a functional group having two or more double bonds that are connected by single bonds, particularly those with cyclic conjugated double bonds such as benzene rings.

[0025] In this invention, the aforementioned base layer is preferably a silicon oxide (SiOx) containing the aforementioned reactive functional groups and the aforementioned cyclic conjugated functional groups.

[0026] In this invention, the aforementioned lubricating layer preferably contains the aforementioned reactive functional groups and the aforementioned δ-charged functional groups. + Modified organosilicon with hydrogen atoms.

[0027] In this invention, preferably, the reactive functional group of the aforementioned basic layer is at least one functional group selected from the group consisting of vinyl, acryloyl, methacryloyl, carboxyl, amino, hydroxyl and epoxy groups, and the cyclic conjugated functional group of the aforementioned basic layer is phenyl.

[0028] In this invention, preferably, the reactive functional group of the aforementioned lubricating layer is at least one functional group selected from the group consisting of carboxyl, vinyl, acryloyl, methacryloyl, amino, hydroxyl, and epoxy groups, and the aforementioned charge is δ. + The hydrogen atom is part of at least one functional group selected from the group consisting of carboxyl, phenolic and hydroxyl groups.

[0029] In this invention, the mass ratio of the cyclic conjugated functional groups of the aforementioned base layer to the reactive functional groups of the aforementioned base layer is preferably 1:1 to 1:3.

[0030] The article of the present invention is characterized by having a surface covered by the aforementioned hydrophobic film.

[0031] The hydrophobic membrane and articles of the present invention exhibit the following effects.

[0032] (1) By appropriately imparting covalently bonded components based on reactive functional groups and components showing π-electron interactions to the base layer and lubrication layer respectively, the weather resistance and slip characteristics after salt spray test are rapidly improved.

[0033] (2) In particular, for the salt spray test, the durability (slip-off properties) improved rapidly compared to using it alone without the combination of covalent bonding and π-electron interaction. This effect was significantly higher than the expected effect when simply combining the two (covalent bonding and π-electron interaction), and can be considered an unexpected result.

[0034] (3) The weather resistance test involves repeated water spraying and drying while being exposed to UV radiation. Covalent bonding is stronger than π-electron interaction; therefore, strengthening the covalent bond between the base layer and the lubricating layer improves weather resistance. However, covalent bonding alone cannot improve the reduction in slip characteristics after the salt spray test. This is believed to be because, during the salt spray test, the high osmotic pressure of the salt water slowly penetrates to the interface between the base layer and the lubricating layer, weakening the force with which the base layer holds the lubricating layer. In contrast, it is believed that with π-electron interaction, the lubricating layer densely covers the base layer, suppressing the impregnation of salt water at the interface between the base layer and the lubricating layer, resulting in better durability against salt spray. However, the bonding of π-electron interaction itself is relatively weak, and therefore significantly weaker in the repeated water spraying and drying weather resistance test.

[0035] In this invention, by appropriately combining the two (covalent bonding and π-electron interaction), it is possible to achieve both a strong bond between the base layer and the lubricating layer and a dense coverage based on the lubricating layer, thus obtaining an improvement effect that cannot be obtained by either approach alone.

[0036] The effects of the invention

[0037] According to the present invention, the charge of the annular conjugated functional groups in the base layer and the charge of the lubricating layer is δ. + In addition to the π-electron interaction of hydrogen atoms, a base layer is formed by modifying the surface of the substrate with reactive functional groups, and a lubricating layer is formed using a polymer containing reactive functional groups covalently bonded to the reactive functional groups. Therefore, a portion of the reactive functional groups of the base layer and a portion of the reactive functional groups of the lubricating layer are covalently bonded. After weather resistance test and salt spray test, the constant or higher slip characteristics brought about by the hydrophobicity of the polymer of the lubricating layer maintained by the base layer are also maintained. Attached Figure Description

[0038] Figure 1 This diagram illustrates the schematic structure of a hydrophobic membrane according to one embodiment of the present invention.

[0039] Figure 2 This is a diagram used to illustrate the aforementioned method for manufacturing hydrophobic films.

[0040] Figure 3 This is an explanatory diagram of the evaluation method for slip characteristics.

[0041] Figure 4 A graph showing the test results of the hydrophobic film constituting 4 (comparative example).

[0042] Figure 5 A graph showing the test results of the hydrophobic film constituting 5 (comparative example).

[0043] Figure 6A diagram showing the test results of the hydrophobic membrane constituting Example 1 (Example).

[0044] Figure 7 A diagram showing the test results of the hydrophobic membrane constituting Example 2 (Example).

[0045] Figure 8 A graph showing the test results of the hydrophobic membrane constituting Example 3 (Example).

[0046] Figure 9 A graph showing the test results of the hydrophobic film constituting 6 (comparative example).

[0047] Figure 10 A graph showing the test results of the hydrophobic film constituting 7 (comparative example).

[0048] Figure 11 The figure shows the test results of the hydrophobic membranes configured in 1-1 (Example) and 1-2 (Example). Detailed Implementation

[0049] [Hydrohydroplaning]

[0050] Figure 1 The figure shows a schematic diagram of a hydrophobic film according to an embodiment of the present invention. In the same figure, the hydrophobic film 10 is formed of a base layer 14 and a lubricating layer 16. The base layer 14 has carbon-carbon double bond-containing groups (vinyl groups) and cyclic conjugated functional groups (phenyl groups) modified on the surface of a glass substrate 12. The lubricating layer 16 is held by the base layer 14 and is composed of a hydrophobic modified silicone oil modified with reactive functional groups (carboxyl groups) that can covalently bond with the vinyl groups of the base layer 14, and a δ-charged group that can interact with the π electrons of the phenyl groups of the base layer 14. + The functional group (phenolic group) of hydrogen atoms is formed by modified hydrophobic silicone oil.

[0051] Furthermore, based on the hydrophobic and hydrophobic properties of the modified silicone oil, which is partially held by the vinyl group of the base layer 14 through covalent bonding and partially held by the phenyl group of the base layer 14 through π-electron interactions, water droplets on the hydrophobic film 10 slide off by slightly tilting the glass substrate 12.

[0052] [Base Layer]

[0053] The base layer 14 of this embodiment is preferably composed of vinyl, phenyl, and fixed groups (e.g., silane) that are firmly bonded to the surface of the glass substrate 12. Acryloyl or methacryloxy groups can also be used as vinyl groups. As silane groups, alkoxysilanes such as tetraethoxysilane (TEOS) or their hydrolysis products, which are firmly bonded to the surface of the glass substrate 12 by covalent bonding, are preferred.

[0054] As a substrate, any material with polar groups such as hydroxyl groups on its surface, such as glass or metal, is acceptable, and good adhesion can be achieved upon hydrolysis of the base layer 14. Therefore, there are no limitations on the glass substrate 12. In the case of a resin substrate, plasma treatment can be performed to form polar groups on the surface.

[0055] Furthermore, the base layer 14 may also contain π-electron functional groups with a high concentration of π electrons, such as phenyl (a functional group having a benzene ring) and alkynyl (a functional group having a carbon triple bond). For example, alkoxysilanes containing phenyl are preferred as materials forming the base layer 14. Examples include phenyltriethoxysilane (PTES), phenyltrimethoxysilane, phenylchlorosilane, and phenylmethylchlorosilane. It should be noted that, in order to increase the π-electron concentration of the π-electron functional groups, for example, a silica structure (SiO2) serving as an insulating site, such as phenyl-insulating sites (Ph-SiO2), is particularly preferred, as it contains the movement of π electrons within the phenyl group. In addition, to enhance the fixation to the surface of the glass substrate 12, alkoxysilanes such as tetraethoxysilane (TEOS) may also be mixed in. If the base layer 14 is formed using these materials, the phenyl group is modified on the surface of the glass substrate 12 by means of the silica structure (SiO2).

[0056] In addition, substances capable of forming the basic layer 14 containing π-electron functional groups include aromatic alcohols such as polystyrene, phenylethanol, phenol, phenanthrene, and tetrahydro-phenanthrene; aromatic aldehydes such as phenylacetaldehyde, methoxybenzaldehyde, anisaldehyde, and hexylcinnamaldehyde; aromatic carboxylic acids such as phthalic acid and benzoic acid; aromatic isocyanates; and aromatic thiols such as thiophenol. Other examples include phenyl chlorides and anilines.

[0057] In addition, as a base layer 14 containing (i) vinyl (acryloyl, methacryloyl) and (ii) phenyl, for example, a mixture of alkoxysilanes obtained by replacing one of the alkoxides of (i) vinyltrimethoxysilane (3-acryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane) and (ii) phenyltriethoxysilane with vinyl (acryloyloxy, methacryloyloxy) and phenyl can be hydrolyzed and formed on a substrate, thereby forming a base layer 14 containing vinyl (acryloyl, methacryloyl) and phenyl.

[0058] When forming the base layer 14 using the above-described substances, it is preferable that the surface of the glass substrate 12 on which the base layer 14 is formed has a solvent affinity for the constituent substances of the base layer 14. Even if it has poor solvent affinity, film formation can still be achieved by treatment with alkali, UV / O3, etc. The surface of such glass substrate 12 can be coated using casting, scraping, dipping, spin coating, etc.

[0059] Furthermore, when cleaning after the formation of base layer 14, organic solvents are suitable. Examples of organic solvents for cleaning include toluene, benzene, pentane, hexane, heptane, cyclohexane, chloromethane, bromomethane, ethyl acetate, diethyl ether, tetrahydrofuran, ethyl cellosolve, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, and chloroform.

[0060] [Lubricating layer]

[0061] The modified silicone oil constituting the lubricating layer 16 of this embodiment is formed as follows: after mixing the various modified silicone oils, it is applied to the base layer 1 and heat-treated (below 300°C) to form the lubricating layer 16. The thickness of the lubricating layer 16 is adjusted by the coating conditions, or it can be adjusted by diluting it with solvents such as methyl ethyl ketone, toluene, and mixtures thereof.

[0062] As a modified silicone oil, for example, Figure 1 Therefore, carboxyl-modified silicones, phenol-modified silicones, etc., are used. These modified silicones (manufactured by Shin-Etsu Chemical Co., Ltd.) all use a silicone backbone that is essentially non-volatile at room temperature and exhibits hydrophobicity to liquids that become slippery. The backbone is modified with functional groups (carboxyl, phenolic, vinyl, acryloyl, methacryloyl, amino, hydroxyl, epoxy, etc.) at two or one end or on the sides, conforming to various modification types. By adjusting the length of the silicone backbone, the viscosity can be set to exhibit the desired flowability. Suitable modified silicone oils have a viscosity range of 4–2000 cps.

[0063] Modified silicone oil can be represented by the following general formula (1).

[0064]

[0065] (In the formula, part of R is, for example, a carboxyl group (-COOH) or a phenol group (C6H5-OH), and the remaining part of R is a methyl group (-CH3).) For example, it can also be the following general formula (2).

[0066]

[0067] The modified organosilicon shown has carboxyl groups at both ends, and is of the following general formula (3).

[0068]

[0069] The image shows a modified organosilicon with phenol at both ends.

[0070] In addition, the modified silicone oil has at least one reactive functional group (e.g., carboxyl, vinyl, acryloyl, methacryloyl, amino, hydroxyl, epoxy, etc.) at at least one end or side chain of the organosilicon backbone (e.g., dimethyl polysiloxane). These reactive functional groups are covalently bonded to other surrounding modified organosilicones, for example, to form cross-linked structures, grafted structures, etc., of the organosilicon backbone 22.

[0071] Alternatively, the base layer 14 may contain reactive functional groups, such as acryloyl and methacryloyl groups, instead of the aforementioned vinyl groups. These reactive functional groups can also form cross-linked or grafted structures through covalent bonding (e.g., polymerization or copolymerization) with other reactive functional groups, such as carboxyl, amino, hydroxyl, and epoxy groups. Alkoxysilanes containing reactive functional groups are preferred as materials for forming this base layer 14. Furthermore, to enhance fixation to the surface of the glass substrate 12, it can be mixed with alkoxysilanes such as tetraethoxysilane (TEOS). If these materials are used to form the base layer 14, it becomes a state where reactive functional groups are modified on the surface of the glass substrate 12 by means of a silica structure (SiO2). It should be noted that a portion of the surface of the base layer 14 containing silicon (Si) with hydroxyl groups (-OH) attached can function as a reactive functional group, as a portion is generated by the hydrolysis of TEOS.

[0072] The modified organosilicon, freshly coated with silicone oil on base layer 14, is liquid, but through heating, polymerization initiators, etc., it can be transformed into a liquid. Figure 1 The reaction of the reactive functional groups proceeds moderately, changing from left to right. The reactive functional groups preferably contain unreacted double bonds. A portion of the modified organosilicon in the lubricating layer 16 is covalently bonded to the reactive functional groups in the base layer 14, resulting in a state where a three-dimensional network structure of modified organosilicon is partially generated in the lubricating layer 16. In other words, the modified silicone oil in the lubricating layer 16 is chemically adsorbed onto the base layer through covalent bonding with the reactive functional groups in the base layer 14, and is thus retained by the surface of the base layer 14. Furthermore, it is believed that a three-dimensional network structure (covalent bonding state between modified organosilicones) is formed in the lubricating layer 16 through cross-linking structures, grafting structures, etc. Additionally, it is believed that when the reactive functional groups are acryloyl or methacryloyl, a polymerization reaction occurs together with the alkyl groups of the organosilicon backbone through thermal reaction.

[0073] On the other hand, the lubricating layer 16 does not completely form a three-dimensional network structure; a portion of the modified organosilicon is directly a one-dimensional or two-dimensional structure, and its organosilicon backbone (also referred to as the slip-off action portion in this specification) contributes to the slipperiness of the hydrophobic film 10. The modified silicone oil can also remain in a partially liquid state. In the case of modified organosilicon with reactive functional groups at both ends, the cross-linking reaction with the surrounding modified organosilicon is stronger. Therefore, moderately mixing modified organosilicon with reactive functional groups at individual ends can be adjusted in a way that does not excessively affect the formation of the three-dimensional network structure of the lubricating layer 16.

[0074] Thus, covalent bonds are partially formed within the liquid lubricating layer 16. Furthermore, the interaction between polymers within the lubricating layer 16 is enhanced, and this interaction also becomes a three-dimensional barrier, making it easier to maintain the state of the lubricating layer 16 held by the base layer 14, thereby improving the durability of the hydrophobic film.

[0075] On the hydrophobic film 10, reactive functional groups (e.g., vinyl groups) are modified on the surface of the base layer 14. Thus, a portion of the modified organosilicon of the lubricating layer 16 is covalently bonded to these reactive functional groups of the base layer 14, and the three-dimensional network structure (cross-linked structure, grafted structure, etc.) of the modified organosilicon formed by the lubricating layer 16 is firmly maintained by the base layer 14.

[0076] Therefore, a portion of the three-dimensional network structure of the modified organosilicon is directly and firmly held by the base layer 14, thereby making the one-dimensional or two-dimensional structure of the modified organosilicon of the lubricating layer 16 more strongly held by the base layer 14.

[0077] like Figure 1 Thus, the lubricating layer 16 comprises a modified organosilicon having at least a single end with a π-electron interaction group (e.g., a phenolic group), and the surface of the base layer 14 is also modified with π-electron functional groups (e.g., phenyl groups).

[0078] The π-electron interaction sites of modified organosilicon (e.g., phenolic groups) exert π-electron interactions with the π-electron functional groups (e.g., phenyl groups) of the base layer 14. For example, the hydrogen (H) atom of the OH group constituting the phenolic group is bonded to the highly electronegative oxygen (O) atom. Therefore, compared to the H atom bonded to the C atom with a similar electronegativity, it is more likely to carry δ electronegativity. + The charge on the substrate exhibits a strong interaction with the π electrons of the π-electron functional group. Through this π-electron interaction, the lubricating layer 16 directly and densely covers the surface of the base layer 14. It should be noted that, in addition to phenolic groups, the functional groups of the modified organosilicon exhibiting the π-electron interaction also include carboxyl and hydroxyl groups.

[0079] A portion of the modified organosilicon is bonded via π-electron interactions with the base layer 14, but this bonding is weaker than covalent bonding, ensuring the fluidity of the modified organosilicon in the main agent.

[0080] In the hydrophobic film 10 of this embodiment, the hydrophobicity and slip properties of the silicone backbone allow the liquid to slide off the hydrophobic film 10 due to the slight tilt of the glass substrate 12 surface. The stable slip properties of the modified silicone allow not only water droplets to slide off, but also mayonnaise, soy sauce, Calbonara sauce, ketchup, coffee, honey, curry sauce, etc., without leaving residue on the surface. Furthermore, hot water, salt water, muddy water, ice, and blood also slide off. In addition, the combination of the base layer 14 and the lubricating layer 16 in this embodiment effectively maintains the hydrophobic film 10 along the surface of substrates with curved surfaces, for example.

[0081] [Manufacturing Method]

[0082] Figure 2 The manufacturing process of the hydrophobic film 10 is shown. As shown in step 1, functional groups (OH groups) are formed on the surface of an article (glass, metal, etc.), here on a glass substrate 12, by UV / O3 treatment or strong alkaline treatment. Additionally, PTES, VTMS (vinyltrimethoxysilane), TEOS, and ethanol (EtOH) are mixed and stirred, and H2O and HClaq for hydrolysis are added and stirred further to prepare a base layer solution. This base layer solution is applied to the surface of the glass substrate 12 by spin coating, dip coating, scraping, casting, or other methods and then dried. This results in a hydrolysis reaction, forming and fixing the base layer 14 onto the surface of the glass substrate 12. It should be noted that phenyl and vinyl groups do not participate in the hydrolysis reaction; therefore, phenyl 14A and vinyl 14B are modified in a suspended manner on the base layer 14.

[0083] Thus, a base layer 14 is formed on the surface of the glass substrate 12. It should be noted that the glass substrate 12 only needs to have polar groups such as OH groups on its surface, as this improves its adhesion to the base layer 14, and is therefore preferred. Furthermore, when the article is made of resin, plasma treatment can be performed to form polar groups on the surface.

[0084] In step 2, the base layer 14 is cleaned with ethanol to remove unreacted PTES and other residues that are not fixed to the surface of the article. Modified silicone oil, which serves as a lubricant, is then applied to the base layer 14 to coat it.

[0085] Modified silicone oils are obtained, for example, by mixing carboxyl-modified organosilicon and phenol-modified organosilicon in a specified ratio. Alternatively, they can be diluted with organic solvents or the like.

[0086] In step 3, the surface of the glass substrate 12 is tilted at an angle of, for example, 0.5 degrees, causing the remaining modified silicone oil to slide off and be removed. This is because a residual lubricating layer 16 is formed when the modified silicone oil is applied. The thickness of the lubricating layer 16 can also be adjusted by changing the coating conditions. In addition, when the modified silicone oil is diluted with solvents such as methyl ethyl ketone, toluene, and mixtures thereof, the thickness of the lubricating layer 16 can also be adjusted by changing the dilution concentration. Finally, in step 4, heat treatment is performed at a surface temperature of 300°C or below to keep the lubricating layer 16 on the base layer 14. As a result, a hydrophobic film 10 with a thickness of about 0.5 to 2 μm is formed on the glass substrate 12, causing the target liquid (water droplets) 40 dropped onto the surface of the lubricating layer 16 to slide off due to the slight tilt of the glass substrate 12 surface.

[0087] In this embodiment, π-electron interactions occur between the phenyl groups contained in the base layer 14 on the surface of the glass substrate 12 and the phenol groups of the phenol-modified organosilicon in the lubricating layer 16. In addition, covalent bonds are formed between the vinyl groups contained in the base layer 14 and the carboxyl groups of the carboxyl-modified organosilicon in the lubricating layer 16. Thus, the lubricating layer 16 is bonded to the base layer 14, and becomes a structure that is not easily removed by simple wiping.

[0088] The carboxyl-modified organosilicon of the lubricating layer 16 is formed by introducing highly reactive organic groups (carboxyl groups) at its ends, and thus, through heat treatment, it is partially covalently bonded to the vinyl group of the base layer 14. This covalent bonding strengthens the interaction between molecules within the hydrophobic film 10, improving weather resistance. Furthermore, when salt water is sprayed onto the hydrophobic film 10, the base layer 14 is densely covered by the lubricating layer 16 through π-electron interactions between the lubricating layer 16 and the base layer 14. Therefore, the impregnation of the interface between the two by the salt water is suppressed, and the slippage resistance becomes less likely to decrease. In other words, good slippage resistance is maintained, and the durability of the hydrophobic film is improved.

[0089] Furthermore, the hydrophobic film 10 of this embodiment promotes planarization through the formation of the base layer 14 and the lubricating layer 16 without forming unevenness on the surface of the glass substrate 12. Therefore, scattering loss based on the glass substrate 12 is less likely to occur. As a result, stable transmittance is obtained, and improved optical properties are expected.

[0090] Example

[0091] The hydrophobic films (compositions 1 to 3) formed by the three combinations of the base layer and lubrication layer in Table 1 will be explained.

[0092] [Table 1]

[0093]

[0094] PTES: phenyltrioxysilane, TEOS: tetraethoxysilane, VTMS: vinyltrimethoxysilane

[0095] <Salt spray resistance test and weather resistance test>

[0096] A hydrophobic film, as shown in Table 1 (compositions 1-3), is formed on a glass plate. Methyl ethyl ketone (MEK) is used as the solvent. For example, the base layers of compositions 1-3 share the same mass ratio of phenyltriethoxysilane (PTES) to vinyltrimethoxysilane (VTMS) to tetraethoxysilane (TEOS) of 0.5:0.5:2. In the lubricating layer of composition 1, the mass ratio of carboxyl-modified organosilicon to phenol-modified organosilicon is set to 1:1. In composition 2, the mass ratio of methacrylamide-modified organosilicon to carboxyl-modified organosilicon is set to 1:1. In the lubricating layer of composition 3, only carboxyl-modified organosilicon is used. The bonding treatment between the base layer and the lubricating layer is performed in a heating furnace at 300°C for 10-20 minutes. The final coating weight of the hydrophobic film is set to 0.05-0.20 mg / cm³. 2 The film thickness is set to the range of 0.5 to 2.0 μm.

[0097] In the salt spray test (according to JIS Z 2371:2015 "Salt spray test method"), the hydrophobic films constituting 1 to 3 were subjected to salt spray for 120 hours to 480 hours, and the slip characteristics of each hydrophobic film were evaluated.

[0098] In addition, in the weather resistance test (based on JISD 0205 "Method for weather resistance test of automotive parts"), the hydrophobic films constituting 1 to 3 are subjected to weather resistance test within the range of 240 hours to 620 hours, and the slip characteristics of each hydrophobic film are evaluated.

[0099] The evaluation of slip characteristics is based on: such as Figure 3 As shown, water was dropped onto the hydrophobic film, the glass plate was tilted, and the angle at which the water droplet began to slide (slip angle) was measured. Seven different diameters of water droplets were set within the range of 1 mm to 2.7 mm. The sliding characteristics were evaluated based on the results of the slip angle for a water droplet diameter of 2 mm.

[0100] Compositions 4 to 5 are shown for comparison. The difference from compositions 1 to 3 is that in composition 4, the base layer is formed from PTES and TEOS (mass ratio 1:2), and the base layer does not contain VTMS, making the lubricating layer of composition 4 solely dimethyl silicone, i.e., unmodified silicone. Furthermore, similarly to composition 4, the base layer of composition 5 is formed from PTES and TEOS (mass ratio 1:2), and the lubricating layer of composition 5 is prepared from phenol-modified silicone, acryloyl-modified silicone, and methacryloyl-modified silicone in a mass ratio of 20:2:2.

[0101] First, the results of the salt spray resistance test and weather resistance test of component 4 used for comparison are shown below. Figure 4 (A) and (B). Comprising 4, such as... Figure 4 As in (A), it did not maintain its slip characteristics after 240 hours of salt spray testing. Additionally, as... Figure 4 As with (B), it did not maintain its slippage characteristic after 120 hours of weather resistance testing. It should be noted that, when evaluating the solvent resistance of component 4, after immersion in acetone for 1 minute, a 2 mm diameter water droplet did not slip off.

[0102] The results of the salt spray resistance test and weather resistance test of component 5 used for comparison are shown below. Figure 5 (A) and (B). Comprising 5, such as... Figure 5 As in (B), the slip characteristics were not maintained after 120 hours of weather resistance testing. It should be noted that regarding the salt spray resistance test... Figure 5 (A) underwent testing up to 120 hours, but no tests were conducted after that. However, based on the results of the weather resistance test, it is not yet conclusive that the long-term slip characteristics can be maintained. Regarding the solvent resistance of component 5, after immersion in acetone for 1 minute, the slip angle of a 1.6 mm diameter water droplet was 40 degrees, which is good.

[0103] Figure 6 (A) and (B) show the test results of salt spray resistance and weather resistance tests for Configuration 1 of Example 1. Configuration 1 exhibits good slip characteristics after both the salt spray resistance test (480 hours) and the weather resistance test (620 hours). It should be noted that, regarding the solvent resistance of Configuration 1, after immersion in acetone for 1 minute, the slip angle of a 1.6 mm diameter water droplet is 60 degrees, which is considered good.

[0104] Figure 7 (A) and (B) show the test results of salt spray resistance test and weather resistance test of configuration 2 of embodiment. In configuration 2, good slip characteristics are shown after both the salt spray resistance test for 360 hours and the weather resistance test for 600 hours.

[0105] Figure 8 (A) and (B) show the test results of salt spray resistance test and weather resistance test of configuration 3 of embodiment 3. In configuration 3, good slip characteristics are shown after both the salt spray resistance test for 480 hours and the weather resistance test for 600 hours.

[0106] Next, in order to illustrate the effects of the embodiments, a comparative test was conducted using configuration 6 (base layer: VTMS: TEOS = 1:2, lubricating layer: carboxyl-modified organosilicon only) which is only covalently bonded. Figure 9(A) and (B) show the results of the salt spray resistance test and weather resistance test for composition 6 used for comparison. For composition 6 that is only covalently bonded, such as... Figure 9 Like (B), it also showed good slip characteristics after 500 hours of weather resistance testing, but as... Figure 9 As in (A), regarding the salt spray resistance test, the slip characteristics could not be maintained for at least 120 hours.

[0107] In addition, a comparative experiment was conducted using a configuration 7 (base layer: PTES: TEOS = 1:2, lubricating layer: phenol-modified organosilicon) that only involves π-electron interactions. Figure 10 (A) and (B) show the results of the salt spray resistance test and weather resistance test for component 7 used for comparison. In component 7, which only involves π-electron interaction, the slip characteristics could not be maintained after at least 120 hours in either the salt spray resistance test or the weather resistance test.

[0108] Therefore, based on Figures 6-8 The test results of the embodiments and Figure 4 , Figure 5 , Figure 9 , Figure 10 When the comparison results are comprehensively evaluated, it can be seen that for a simple combination of covalent bonding and π-electron interaction, the samples (configurations 1 to 3) of the examples do not produce easily predictable results.

[0109] Next, a hydrophobic film identical to that of Configuration 1 (Configuration 1-1) and a film with altered silane composition ratios in the base layer (Configuration 1-2) were prepared, and their slip characteristics after weather resistance testing were evaluated. The compositions of each are shown in Table 2. In the base layer of Configuration 1-1, the mass ratio of PTES to VTMS to TEOS is 0.5:0.5:2, but in the base layer of Configuration 1-2, their mass ratio is 0.25:0.75:2. That is, the mass ratio of phenyl (cyclic conjugated functional groups) to vinyl (reactive functional groups) components in the base layer is as follows: 1:1 in Configuration 1-1 and 1:3 in Configuration 1-2.

[0110] [Table 2]

[0111]

[0112] A:PTES, C:VTMS, B:TEOS

[0113] It should be noted that the modified organosilicones used in the lubricating layer are all manufactured by Shin-Etsu Chemical Industry Co., Ltd. In components 1-1 and 1-2, two-terminal phenol-modified organosilicones and two-terminal carboxyl-modified organosilicones are used at a mass ratio of 1:1. Furthermore, components 1-1 and 1-2 are diluted with methyl ethyl ketone (7.5% volume percentage) to achieve a modified organosilicon concentration of 22.5% in the lubricating layer.

[0114] Figure 11 The results of the weather resistance test constituting 1-1 are shown in (A). Figure 11 (B) shows the results of the weather resistance test for components 1-2. The hydrophobic films of components 1-1 and 1-2 maintain the same level of slip characteristics as those of component 1 (up to 500 hours after the weather resistance test).

[0115] Explanation of reference numerals in the attached figures

[0116] 10. Hydroplaning membrane

[0117] 12··· Glass substrate

[0118] 14···Basic Layer

[0119] 14A··phenyl

[0120] 14B Vinyl

[0121] 16··· Lubrication layer

[0122] 40··· Slipping object liquid

Claims

1. A hydrophobic membrane, characterized in that, It comprises: a base layer formed on a substrate, and a lubricating layer held by the base layer. The base layer is obtained by modifying the surface of the substrate with reactive functional groups. The lubricating layer is composed of a polymer containing reactive functional groups, which can covalently bond with the reactive functional groups of the base layer. The base layer contains cyclic conjugated functional groups modified on the surface of the substrate. The lubricating layer contains a charge δ + High molecules with hydrogen atoms A portion of the cyclic conjugated functional groups in the base layer are charged with a charge δ in the lubricating layer. + A portion of the hydrogen atoms undergo π-electron interactions.

2. The hydrophobic membrane according to claim 1, wherein, The reactive functional group is at least one functional group selected from the group consisting of carbon-carbon double bond groups, carboxyl groups, amino groups, hydroxyl groups and epoxy groups.

3. The hydrophobic membrane according to claim 1 or 2, wherein, The base layer is a silicon oxide (SiOx) containing the reactive functional groups and the cyclic conjugated functional groups.

4. The hydrophobic membrane according to claim 1 or 2, wherein, The lubricating layer contains the aforementioned reactive functional groups and the charged element with a charge of δ. + Modified organosilicon with hydrogen atoms.

5. The hydrophobic membrane according to claim 1 or 2, wherein, The reactive functional group of the base layer is at least one selected from the group consisting of vinyl, acryloyl, methacryloyl, carboxyl, amino, hydroxyl, and epoxy groups. The cyclic conjugated functional group of the base layer is phenyl.

6. The hydrophobic membrane according to claim 1 or 2, wherein, The reactive functional group of the lubricating layer is at least one selected from the group consisting of carboxyl, vinyl, acryloyl, methacryloyl, amino, hydroxyl, and epoxy groups, and the charge is δ. + The hydrogen atom is part of at least one functional group selected from the group consisting of carboxyl, phenolic and hydroxyl groups.

7. The hydrophobic membrane according to claim 1 or 2, wherein, The mass ratio of the cyclic conjugated functional groups in the base layer to the reactive functional groups in the base layer is 1:1 to 1:

3.

8. An article having a surface covered by a hydrophobic film according to any one of claims 1 to 7.

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