Hypoallergenic film, and articles having a hypoallergenic film on their surface

Abstract

The present invention is a water-slip membrane 10 that can maintain fixed drop characteristics or greater even after a weathering test or saline spray test, the water-slip membrane comprising a base layer 14 formed on a glass base material 12, and a lubricating layer 16 held on the base layer 14. The base layer 14 is formed by modifying a reactive functional group on the surface of the glass base material 12, and the lubricating layer 16 is composed of a polymer containing a reactive functional group capable of covalent bonding with the reactive functional group of the base layer 14. A portion of the reactive functional group of the base layer 14 and a portion of the reactive functional group of the lubricating layer 16 are covalently bonded. Furthermore, the base layer 14 contains a cyclic conjugated functional group modified on the surface of the glass base material 12, and the lubricating layer 16 includes a polymer containing hydrogen atoms charged to δ+. A portion of the cyclic conjugated functional group of the base layer 14 and a portion of the hydrogen atoms charged to δ+ of the lubricating layer 16 have π-electron interaction.

Description

Related Application

[0001] This application claims the priority of Japanese Patent Application No. 2021-122645 filed on July 27, 2021, which is incorporated herein by reference.

Technical Field

[0002] The present invention relates to an article having a water-repellent film composed of a base layer and a lubricating layer held on the base layer, and a surface coated thereby.

Background Art

[0003] In order to obtain non-wetting properties (falling characteristics) with respect to a liquid, there is an idea of forming a film of a lubricating liquid on the surface of an article. In the conventional technology, in order to prevent the outflow of the lubricating liquid, it is necessary to form a microporous structure in advance on the surface of the article and hold the lubricating liquid in the microporous structure.

[0004] On the other hand, the synovial membrane of Patent Document 1 has a feature that the base layer holds the lubricating liquid by π-electron interaction, and it is noted that it is not necessary to form a microporous structure on the surface of the article and slipperiness can be imparted to a flat surface.

[0005] In recent years, due to the progress of image processing technology, cameras and lenses have been miniaturized, and the characteristics of water droplet adhesion at a small-area image capture port have been emphasized. Conventionally, the evaluation of the adhesion characteristics of water droplets has been mostly by visual inspection, and has been performed using water droplets or liquid droplets of 10 μl or more that can be easily formed with a dropper. However, it has been found that the smaller the liquid droplet, the greater the influence on visibility. This is because the adhesion force increases due to slight depressions or dirt on the surface as the liquid droplet becomes smaller.

[0006] Patent Document 1 evaluates the sliding characteristics of water droplets of 10 μl or more, and does not evaluate droplets smaller than that. Furthermore, Patent Document 1 also reports that on superhydrophobic surfaces (SHS), 5 μl droplets have their movement hindered by the surface irregularities, making them difficult to slide off. For this reason, the inventors have established a method for forming a surface on which droplets of 4 μl or less (diameter φ = 2 mm or less) can also slide off. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Patent No. 6678018 [Overview of the project] [Problems that the invention aims to solve]

[0008] While the inventors were working to commercialize the synovial film described in Patent Document 1, they encountered a problem: the synovial film in Patent Document 1 could not maintain the rolling characteristics of water droplets with a diameter of 1 to 2.5 mm after a 120-hour weathering test and a 240-hour salt spray test (they did not roll off).

[0009] The object of the present invention is to provide a water-repellent film comprising a base layer formed on a substrate and a lubricating layer held in the base layer, which maintains a certain level of slip resistance even after weathering tests and salt spray tests. [Means for solving the problem]

[0010] To solve the aforementioned problems, the inventors conducted diligent research and found that by using a substrate surface modified with reactive functional groups as the base layer, and forming a lubricating layer using a polymer containing reactive functional groups that covalently bond with the reactive functional groups, some of the reactive functional groups in the base layer and some of the reactive functional groups in the lubricating layer covalently bond, thereby maintaining a certain level of slip resistance even after weathering tests and salt spray tests, thus completing the present invention.

[0011] In other words, the hydrophobic film according to the present invention is It comprises a base layer formed on a substrate and a lubricating layer held in 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 that can be covalently bonded to the reactive functional groups of the base layer. A portion of the reactive functional groups in the base layer and a portion of the reactive functional groups in the lubricating layer are covalently bonded. Furthermore, the base layer contains cyclic conjugated functional groups that are modified on the surface of the substrate. The lubricating layer is δ + The polymer contains charged hydrogen atoms, A portion of the cyclic conjugated functional groups of the base layer and the δ of the lubricating layer + It is characterized by π-electron interaction with a portion of the charged hydrogen atoms.

[0012] Here, the "reactive functional group" is preferably at least one functional group selected from the group consisting of carbon-carbon double bond-containing groups, carboxyl groups, amino groups, hydroxyl groups, and epoxy groups. Furthermore, "covalently bonded" includes polymerization reactions, copolymerization reactions, crosslinked structures, and graft structures. In addition, "cyclic conjugated functional group" refers to a functional group having a conjugated double bond in which two or more double bonds are connected with a single bond in between, and in particular, one in which the conjugated double bond forms a ring, such as a benzene ring.

[0013] In the present invention, the base layer is preferably a silicon oxide (SiOx) containing the reactive functional group and the cyclic conjugated functional group.

[0014] In the present invention, the lubricating layer comprises the reactive functional group and the δ + It is preferable that the modified silicone contains charged hydrogen atoms.

[0015] In the present invention, the reactive functional group of the base layer is at least one functional group selected from the group consisting of a vinyl group, an acrylic group, a methacrylic group, a carboxy group, an amino group, a hydroxy group, and an epoxy group, and the cyclic conjugated functional group of the base layer is preferably a phenyl group.

[0016] In the present invention, the reactive functional group of the lubricating layer is at least one functional group selected from the group consisting of a carboxy group, a vinyl group, an acrylic group, a methacrylic group, an amino group, a hydroxy group, and an epoxy group, and the hydrogen atom charged to the δ + is preferably a part of at least one functional group selected from the group consisting of a carboxy group, a phenol group, and a hydroxy group.

[0017] In the present invention, the mass ratio of the component of the cyclic conjugated functional group of the base layer to the component of the reactive functional group of the base layer is preferably 1:1 to 1:3.

[0018] The article according to the present invention is characterized by having a surface coated with the water-skiing film.

[0019] The water-skiing film and the article according to the present invention exhibit the following effects. (1) By appropriately imparting a covalent bond component due to a reactive functional group and a component exhibiting π-electron interaction to the base layer and the lubricating layer, respectively, the weather resistance and the falling characteristics after a salt water spray test are dramatically improved. (2) In particular, for the salt water spray test, the durability performance (falling characteristics) is dramatically improved as compared with the case where the covalent bond and the π-electron interaction are used alone without combination. Such an effect far exceeds the effect expected when the two (covalent bond and π-electron interaction) are simply combined, and can be said to be an unexpected effect. (3) The weather resistance test is a test that repeats watering and drying while performing UV irradiation. Since the covalent bond has a stronger bond compared to the π-electron interaction, strengthening the covalent bond between the base layer and the lubricating layer has an improving effect on weather resistance. However, the decline in the falling characteristics after the salt water spray test could not be improved by only the covalent bond. The reason is considered to be that in the salt water spray test, salt water with a high osmotic pressure gradually penetrates into the interface between the base layer and the lubricating layer, weakening the force of the base layer to hold the lubricating layer. On the other hand, when using the π-electron interaction, it is considered that the lubricating layer closely covers the base layer, suppressing the immersion of salt water into the interface between the base layer and the lubricating layer, and the durability against salt water spray becomes relatively good. However, since the bond of the π-electron interaction itself is weak, it is extremely weak for the weather resistance test that repeats watering and drying. In the present invention, by appropriately combining both (covalent bond and π-electron interaction), it is considered that it is possible to achieve both a strong bond between the base layer and the lubricating layer and the tightness of the coating by the lubricating layer, and an improving effect that could not be achieved alone was obtained.

Effects of the Invention

[0020] According to the present invention, in addition to the π-electron interaction between the cyclic conjugated system functional group of the base layer and the δ-hydrogen atom charged in the lubricating layer, a base layer is formed by modifying the surface of the substrate with a reactive functional group, and a lubricating layer is formed using a polymer containing a reactive functional group that covalently bonds with the reactive functional group. As a result, a part of the reactive functional group of the base layer and a part of the reactive functional group of the lubricating layer are covalently bonded, and even after the weather resistance test or the salt water spray test, a falling characteristic of a certain level or more due to the water repellency of the polymer of the lubricating layer held on the base layer is maintained.

Brief Description of the Drawings

[0021] [Figure 1] It is a diagram showing a schematic structure of a water repellent film according to an embodiment of the present invention. [Figure 2] It is a diagram for explaining the manufacturing method of the water repellent film. [Figure 3] It is an explanatory diagram of an evaluation method for falling characteristics. ​​ [Figure 4] This graph shows the test results of the hydrophobic film of Composition 4 (Comparative Example). [Figure 5] This graph shows the test results of the hydrophobic film of Composition 5 (Comparative Example). [Figure 6] This graph shows the test results of the hydrophobic film of Configuration 1 (Example). [Figure 7] This graph shows the test results of the hydrophobic film in Configuration 2 (Example). [Figure 8] This graph shows the test results of the hydrophobic film in Configuration 3 (Example). [Figure 9] This graph shows the test results of the hydrophobic film of Composition 6 (Comparative Example). [Figure 10] This graph shows the test results of the hydrophobic film of Composition 7 (Comparative Example). [Figure 11] This graph shows the test results of the hydrophobic films of configuration 1-1 (Example) and configuration 1-2 (Example). [Modes for carrying out the invention]

[0022] [Synovial membrane] Figure 1 shows a schematic diagram of a hydrophobic film according to one embodiment of the present invention. In the figure, the hydrophobic film 10 consists of a base layer 14 having carbon-carbon double bond-containing groups (vinyl groups) and cyclic conjugated functional groups (phenyl groups) modified on the surface of a glass substrate 12, and a lubricating layer 16 held in the base layer 14. The lubricating layer 16 consists of a hydrophobic modified silicone oil modified with reactive functional groups (carboxyl groups) that can covalently bond to the vinyl groups of the base layer 14, and δ that can π-interact with the phenyl groups of the base layer 14. + It consists of a hydrophobic modified silicone oil modified with a functional group (phenol group) having a charged hydrogen atom.

[0023] Furthermore, due to the hydrophobic and hydrophobic properties of the modified silicone oil, which is partially held by covalent bonds to the vinyl groups of the base layer 14, and the modified silicone oil, which is partially held by π-electron interactions to the phenyl groups of the base layer 14, water droplets on the hydrophobic film 10 slide off when the glass substrate 12 is tilted slightly.

[0024] [Base layer] In this embodiment, the base layer 14 preferably has a fixing group (e.g., a silane group) that firmly bonds to the surface of the glass substrate 12, along with vinyl groups and phenyl groups. Acrylic groups and methacrylic groups can also be used as vinyl groups. As the silane group, it is preferable to use an alkoxysilane such as tetraethoxysilane (TEOS) or a hydrolysis product thereof, which firmly bonds to the surface of the glass substrate 12 by covalent bonding.

[0025] As a substrate, any material having polar groups such as hydroxyl groups on its surface, such as glass or metal, can provide good adhesion during the hydrolysis of the base layer 14. Therefore, it is not limited to glass substrates 12. In the case of resin substrates, plasma treatment can be applied to form polar groups on the surface.

[0026] Furthermore, the base layer 14 may also contain π-electron functional groups having a high concentration of π electrons, such as phenyl groups (functional groups having a benzene ring) and alkynyl groups (functional groups having a triple bond between carbon atoms). For example, alkoxysilanes containing phenyl groups are preferred as the material for forming the base layer 14. Examples include phenyltriethoxysilane (PTES), phenyltrimethoxysilane, phenylchlorosilane, and phenylmethylchlorosilane. In order to increase the π-electron concentration of the π-electron functional group, it is particularly preferable that the silica structure (SiO2), which is the insulating site, contains the movement of π electrons within the phenyl group, for example, in a phenyl group-insulating site (Ph-SiO2, etc.). Additionally, alkoxysilanes such as tetraethoxysilane (TEOS) may be mixed in to reinforce fixation to the surface of the glass substrate 12. When the base layer 14 is formed using these materials, the phenyl groups are modified on the surface of the glass substrate 12 via the silica structure (SiO2).

[0027] Other substances capable of forming a base layer 14 containing π-electron functional groups include polystyrene, aromatic alcohols such as phenethyl alcohol, phenol, phenanthrenol, and cresol tetrahydrophenanthrenol, aromatic aldehydes such as phenylacetaldehyde, methoxybenzaldehyde, cuminaldehyde, and hexyl cinnamaldehyde, aromatic carboxylic acids such as phenanthrene carboxaldehyde, phthalic acid, and benzoic acid, aromatic isocyanates, aromatic thiols such as thiophenol, and also phenyl chlorides and anilines.

[0028] Furthermore, as a base layer 14 containing (i) vinyl groups (acrylic groups, methacrylic groups) and (ii) phenyl groups, for example, a base layer 14 containing vinyl groups (acrylic groups, methacrylic groups) and phenyl groups can be formed by hydrolyzing a mixture of (i) vinyltrimethoxysilane (3-acryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane) and (ii) alkoxysilane in which one of the alkoxides such as phenyltriethoxysilane is substituted with a vinyl group (acryloxy group, methacryloxy group) or a phenyl group, and forming a film on a substrate.

[0029] To form the base layer 14 using the above materials, it is preferable to first make the surface of the glass substrate 12 on which the base layer 14 is formed solubility toward the constituent materials of the base layer 14. Even if it is poor solvent, film formation is possible by using alkali treatment or UV / O3 treatment in combination. On such a glass substrate 12 surface, methods such as casting, squeegeeing, dipping, and spin coating can be used.

[0030] Furthermore, when washing is performed after the formation of the base layer 14, it is preferable to use an organic solvent. Examples of organic solvents for washing include toluene, benzene, pentane, hexane, heptane, cyclohexane, methyl chloride, methyl bromide, ethyl acetate, diethyl ether, tetrahydrofuran, ethyl cellosolve, acetone, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, and chloroform.

[0031] [Lubricating layer] The modified silicone oil constituting the lubricating layer 16 in this embodiment is formed by mixing each modified silicone oil, applying it onto the base layer 14, and then subjecting it to heat treatment (300°C or less). The thickness of the lubricating layer 16 may be adjusted by the application conditions, or by diluting it with a solvent such as methyl ethyl ketone, toluene, or a mixture thereof.

[0032] As modified silicone oils, for example, carboxy-modified silicones and phenol-modified silicones are used, as shown in Figure 1. These modified silicones (manufactured by Shin-Etsu Chemical Co., Ltd.) all have a silicone main chain that is virtually non-volatile at room temperature and exhibits hydrophobicity towards the liquid to be slid. They are modified with functional groups (carboxyl groups, phenol groups, vinyl groups, acrylic groups, methacrylic groups, amino groups, hydroxyl groups, epoxy groups, etc.) corresponding to the respective modification type at one or both ends or sides of the silicone main chain. The viscosity can be set to exhibit the desired fluidity by adjusting the length of the silicone main chain. Suitable modified silicone oils have a viscosity range of 4 to 2000 cps.

[0033] Modified silicone oil is defined by the following general formula (1)

[0034] [ka] (In the formula, part of R may be, for example, a carboxyl group (-COOH) or phenol (C6H5-OH), and the remaining part of R may be a methyl group (-CH3).) For example, the following general formula (2)

[0035] [ka] Modified silicones having carboxyl groups at both ends, represented by the following general formula (3)

[0036] [ka] It may also be a modified silicone having phenol at both ends, represented as .

[0037] Furthermore, the modified silicone oil has a reactive functional group (e.g., carboxyl group, vinyl group, acrylic group, methacrylic group, amino group, hydroxyl group, epoxy group, etc.) at at least one end or side chain of the silicone main chain (e.g., dimethylpolysiloxane). These reactive functional groups can covalently bond with other modified silicones in the surrounding area, forming, for example, crosslinked structures or graft structures of the silicone main chain 22.

[0038] Furthermore, the base layer 14 may also include the following reactive functional groups instead of the vinyl groups (acrylic groups, methacrylic groups) mentioned above. These reactive functional groups can form crosslinked structures or graft structures through covalent bonding with other reactive functional groups (e.g., polymerization reactions, copolymerization reactions), such as carboxyl groups, amino groups, hydroxyl groups, and epoxy groups. As a material for forming such a base layer 14, alkoxysilanes containing reactive functional groups are preferred. In addition, alkoxysilanes such as tetraethoxysilane (TEOS) may be mixed in to reinforce fixation to the surface of the glass substrate 12. When the base layer 14 is formed using these materials, the reactive functional groups are modified on the surface of the glass substrate 12 via the silica structure (SiO2). Note that hydrolysis of TEOS may create portions on the surface of the base layer 14 where silicon (Si) is bonded to a hydroxyl group (-OH), and these portions can act as reactive functional groups.

[0039] Immediately after the silicone oil is applied to the base layer 14, the modified silicone is in a liquid state, but the reaction of the reactive functional groups proceeds appropriately due to heating and polymerization initiators, as shown in the change from left to right in Figure 1. The reactive functional groups preferably contain unreacted double bonds. A portion of the modified silicone in the lubricating layer 16 covalently bonds with the reactive functional groups of the base layer 14, resulting in a partially formed three-dimensional network structure of the modified silicone within the lubricating layer 16. In other words, the modified silicone oil in the lubricating layer 16 is retained on the surface of the base layer 14 in a state of chemical adsorption to the base layer 14 through covalent bonding with the reactive functional groups of the base layer 14. It is also conceivable that a three-dimensional network structure is formed within the lubricating layer 16 by crosslinking structures or graft structures (covalent bonding state between modified silicones). Furthermore, if the reactive functional groups are acrylic groups or methacrylic groups, it is also conceivable that polymerization reactions occur with the alkyl groups of the silicone main chain due to thermal reactions.

[0040] On the other hand, the lubricating layer 16 does not form a completely three-dimensional network structure; a portion of the modified silicone remains in a one-dimensional or two-dimensional structure, and its silicone main chain portion (also referred to as the sliding portion in this book) contributes to the sliding properties of the hydrophobic film 10. The modified silicone oil may remain partially in a liquid state. In the case of modified silicone with reactive functional groups at both ends, the crosslinking reaction with the surrounding modified silicone is relatively strong, so by mixing in a moderate amount of modified silicone with a reactive functional group at one end, it is possible to adjust the formation of the three-dimensional network structure of the lubricating layer 16 so that it does not become excessive.

[0041] In this way, covalent bonds are partially formed within the liquid lubricating layer 16, and the interactions between polymers are strengthened within the lubricating layer 16. This effect also acts as a 3D obstacle, making it easier to maintain the state in which the lubricating layer 16 is held by the base layer 14, thereby improving the durability of the hydrophobic film.

[0042] Since the surface of the base layer 14 of the hydrophobic film 10 is modified with reactive functional groups (e.g., vinyl groups), some of the modified silicone in the lubricating layer 16 covalently bonds with these reactive functional groups of the base layer 14, and the three-dimensional network structure (such as a cross-linked structure or graft structure) of the modified silicone formed in the lubricating layer 16 is firmly held by the base layer 14.

[0043] Therefore, a portion of the three-dimensional network structure of the modified silicone is directly and firmly held to the base layer 14, thereby allowing the one-dimensional or two-dimensional structure of the modified silicone in the lubricating layer 16 to be more strongly held to the base layer 14.

[0044] As shown in Figure 1, the lubricating layer 16 contains a modified silicone having a π-electron interaction moiety (e.g., a phenol group) at at least one end, and the surface of the base layer 14 is also modified with π-electron functional groups (e.g., a phenyl group).

[0045] The π-electron interacting portion of the modified silicone (e.g., a phenol group) interacts with the π-electron functional group (e.g., a phenyl group) of the base layer 14. For example, the hydrogen (H) atom of the OH group constituting the phenol group is bonded to an oxygen (O) atom with high electronegativity, so compared to an H atom bonded to a C atom with similar electronegativity, the δ + It readily acquires an electric charge and exhibits strong interactions with the π electrons of the π-electron functional group. This π-electron interaction allows the lubricating layer 16 to directly and densely coat the surface of the base layer 14. In addition to the phenol group, other functional groups of modified silicones that exhibit π-electron interactions include carboxyl groups and hydroxyl groups.

[0046] Thus, a portion of the modified silicone is bonded to the base layer 14 by π-electron interactions, but this bond is weaker than a covalent bond, and the fluidity of the main modified silicone component is ensured.

[0047] In the hydrophobic film 10 of this embodiment, the hydrophobic and slippery properties of the silicone main chain allow the liquid to slide off the hydrophobic film 10 to slide off due to the slight incline of the glass substrate 12 surface. The stable slippery performance of the modified silicone allows not only water droplets but also mayonnaise, soy sauce, carbonara sauce, ketchup, coffee, honey, curry sauce, etc., to slide off without leaving any residue on the surface. Furthermore, hot water, salt water, muddy water, ice, and blood also slide off in the same way. In addition, the combination of the base layer 14 and the lubricating layer 16 of this embodiment ensures that the hydrophobic film 10 is well maintained along the surface, even on substrates with curved surfaces.

[0048] [Manufacturing method] Figure 2 shows the manufacturing process of the hydrophobic film 10. As shown in step 1, functional groups (OH groups) are formed on the surface of an article (glass, metal, etc.), in this case on a glass substrate 12, by UV / O3 treatment or strong alkaline solution treatment. In addition, PTES, VTMS (vinyltrimethoxysilane), TEOS, and ethanol (EtOH) are mixed and stirred, and H2O and HClaq for hydrolysis are added and stirred further to create a base layer solution. This base layer solution is applied to the surface of the glass substrate 12 by spin coating, dip method, squeegee method, casting method, etc., and dried. This causes a hydrolysis reaction, and the base layer 14 is formed and fixed on the surface of the glass substrate 12. Note that phenyl groups and vinyl groups do not participate in the hydrolysis reaction, so phenyl groups 14A and vinyl groups 14B are modified on the base layer 14 in a pendant-like manner.

[0049] In this way, a base layer 14 is formed on the surface of the glass substrate 12. It is preferable that the glass substrate 12 has polar groups such as OH groups on its surface, as this increases the bonding with the base layer 14. If the article is made of resin, it is preferable to form polar groups on the surface by plasma treatment.

[0050] In step 2, the base layer 14 is washed with ethanol to remove any unreacted PTES or other residues that were not fixed to the surface of the article, and then modified silicone oil is applied to the base layer 14 as a lubricant by drop.

[0051] Modified silicone oil is, for example, a mixture of carboxy-modified silicone and phenol-modified silicone in a predetermined ratio, which is then stirred and mixed. Alternatively, these can be diluted with an organic solvent.

[0052] In step 3, the surface of the glass substrate 12 is tilted, for example, at an angle of 0.5 degrees, to remove excess modified silicone oil by allowing it to slide off. This is because an excess 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. Furthermore, the thickness of the lubricating layer 16 can also be adjusted by changing the dilution concentration when diluting the modified silicone oil with solvents such as methyl ethyl ketone, toluene, and mixtures thereof. Finally, in step 4, heat treatment is applied to reduce the surface temperature to 300°C or lower to retain the lubricating layer 16 on the base layer 14. This forms a water-repellent film 10 with a thickness of approximately 0.5 to 2 μm on the glass substrate 12, and the liquid (water droplets) 40 that are to slide off the surface of the lubricating layer 16 will slide off due to the slight tilt of the glass substrate 12 surface.

[0053] 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 silicone of the lubricating layer 16, and covalent bonds are formed between the vinyl groups contained in the base layer 14 and the carboxyl groups of the carboxy-modified silicone of the lubricating layer 16. As a result, the lubricating layer 16 becomes bonded to the base layer 14, creating a structure that is difficult to remove by simple wiping.

[0054] The carboxy-modified silicone of the lubricating layer 16 has highly reactive organic groups (carboxyl groups) introduced at its ends, so that some of them covalently bond with the vinyl groups of the base layer 14 upon heat treatment. This covalent bonding strengthens the interactions between molecules within the hydrophobic film 10, improving its weather resistance. Furthermore, when saltwater is sprayed onto the hydrophobic film 10, the π-electron interaction between the lubricating layer 16 and the base layer 14 causes the base layer 14 to be densely coated with the lubricating layer 16, suppressing the penetration of saltwater into the interface between the two layers and preventing a decrease in sliding properties. In other words, good sliding properties are maintained and the durability of the hydrophobic film is improved.

[0055] Furthermore, the water-repellent film 10 according to this embodiment does not require the formation of irregularities on the surface of the glass substrate 12. Rather, the formation of the base layer 14 and the lubricating layer 16 promotes flattening, thus reducing scattering loss due to the glass substrate 12. As a result, stable transmittance can be obtained, and an improvement in optical properties can be expected.

[0056] Examples Table 1 describes the three different combinations of base layer and lubricating layer used to create the hydrophobic film (compositions 1-3).

[0057] [Table 1]

[0058] <Salt spray resistance test and weather resistance test> A hydrophobic film was created on a glass plate as shown in Structures 1-3 of Table 1. Methyl ethyl ketone was used as the solvent. For example, the base layers of Structures 1-3 all share the same mass ratio of phenyltriethoxysilane (PTES), vinyltrimethoxysilane (VTMS), and tetraethoxysilane (TEOS), which is 0.5:0.5:2. In the lubricating layer of Structure 1, the mass ratio of carboxy-modified silicone to phenol-modified silicone was 1:1. In Structure 2, the mass ratio of methacrylic-modified silicone to carboxy-modified silicone was 1:1. In the lubricating layer of Structure 3, only carboxy-modified silicone was used. The bonding treatment between the base layer and the lubricating layer was performed in a heating furnace at 300°C for 10-20 minutes. The final coating amount of the hydrophobic film was 0.05-0.20 mg / cm². 2 The range was set to 0.5 to 2.0 μm, and the film thickness was set to 0.5 to 2.0 μm.

[0059] In the salt spray resistance test (conforms to JIS Z 2371:2015 "Salt Spray Test Method"), the hydrophobic films of components 1 to 3 are subjected to salt spray for a range of 120 to 480 hours, and then the slippage characteristics of each hydrophobic film are evaluated. Furthermore, in the weathering test (in accordance with JIS D 0205 "Weathering Test Method for Automotive Parts"), the hydrophobic films of components 1 to 3 are subjected to weathering tests for a range of 240 to 620 hours, and then the slippage characteristics of each hydrophobic film are evaluated. The sliding characteristics are evaluated by dropping water onto a water-repellent film, tilting the glass plate, and measuring the angle at which the water droplet begins to slide (sliding angle), as shown in Figure 3. The water droplet diameter is set to seven different sizes ranging from 1 mm to 2.7 mm, and the sliding characteristics are evaluated based on the sliding angle results for a 2 mm diameter water droplet.

[0060] Compositions 4 and 5 are shown for comparison. The differences from compositions 1 to 3 are that in composition 4, the base layer is formed with PTES and TEOS (mass ratio 1:2), and VTMS is not included in the base layer, and the lubricating layer of composition 4 is made of dimethyl silicone only, i.e., unmodified silicone. Also, the base layer of composition 5 is formed with PTES and TEOS (mass ratio 1:2) in the same way as composition 4, and the lubricating layer of composition 5 is prepared with phenol-modified silicone, acrylic-modified silicone, and methacrylic-modified silicone in a mass ratio of 20:2:2.

[0061] First, the measurement results of the salt spray resistance test and weather resistance test for the comparative configuration 4 are shown in Figures 4(A) and (B). In configuration 4, as shown in Figure 4(A), the droplet did not maintain its rolling characteristics after 240 hours of the salt spray resistance test. Also, as shown in Figure 4(B), the droplet did not maintain its rolling characteristics after 120 hours of the weather resistance test. Furthermore, when the solvent resistance of configuration 4 was evaluated, a 2 mm diameter water droplet did not roll off after 1 minute of acetone immersion.

[0062] Figures 5(A) and (B) show the measurement results of the salt spray resistance test and weather resistance test for the comparative configuration 5. In configuration 5, the rolling characteristics were not maintained after 120 hours of weather resistance testing, as shown in Figure 5(B). Note that the salt spray resistance test (Figure 5(A)) was conducted up to 120 hours, but no tests were conducted beyond that. However, even from the results of the weather resistance test, it is unlikely that the rolling characteristics will be maintained over a long period. Regarding the solvent resistance of configuration 5, after 1 minute of acetone immersion, the rolling angle of a 1.6 mm diameter water droplet was 40 degrees, which was good.

[0063] Figures 6(A) and (B) show the measurement results of the salt spray resistance test and weather resistance test for Configuration 1 according to the example. Configuration 1 showed good rolling characteristics both after 480 hours in the salt spray resistance test and after 620 hours in the weather resistance test. Regarding the solvent resistance of Configuration 1, after 1 minute of acetone immersion, the rolling angle of a 1.6 mm diameter water droplet was 60 degrees, which was good.

[0064] Figures 7(A) and (B) show the measurement results of the salt spray resistance test and weather resistance test for Configuration 2 of the example. Configuration 2 showed good fall resistance characteristics both after 360 hours of the salt spray resistance test and after 600 hours of the weather resistance test.

[0065] Figures 8(A) and (B) show the measurement results of the salt spray resistance test and weather resistance test for Configuration 3 of the example. Configuration 3 showed good fall resistance characteristics both after 480 hours of the salt spray resistance test and after 600 hours of the weather resistance test.

[0066] Next, to explain the effects of the examples, a comparative test was conducted using configuration 6 consisting only of covalent bonds (base layer: VTMS:TEOS = 1:2, lubricating layer: carboxy-modified silicone only). Figures 9(A) and (B) show the measurement results of the salt spray resistance test and weather resistance test for configuration 6 used for comparison. In configuration 6 consisting only of covalent bonds, as shown in Figure 9(B), good rolling characteristics were observed even after 500 hours of weather resistance testing. However, as shown in Figure 9(A), rolling characteristics could not be maintained after at least 120 hours of salt spray resistance testing.

[0067] Furthermore, a comparative test was conducted using configuration 7, which consists solely of π-electron interactions (base layer: PTES:TEOS = 1:2, lubrication layer: phenol-modified silicone). Figures 10(A) and (B) show the measurement results of the salt spray resistance test and weather resistance test for configuration 7 used for comparison. With configuration 7, which consists solely of π-electron interactions, the rolling characteristics could not be maintained after at least 120 hours in both the salt spray resistance test and the weather resistance test.

[0068] Therefore, a comprehensive evaluation based on the test results of the examples in Figures 6 to 8 and the comparison results in Figures 4, 5, 9, and 10 reveals that effects that cannot be easily predicted by a simple combination of covalent bonding and π-electron interaction can be obtained in the example samples (configurations 1 to 3).

[0069] Next, we created a hydrophobic film identical to that of composition 1 (composition 1-1) and a composition 1-2 in which the component ratios of each silane in the base layer were changed, and evaluated the rolling characteristics after the weathering test. The respective compositions are shown in Table 2. In the base layer of composition 1-1, the mass ratio of PTES, VTMS, and TEOS is 0.5:0.5:2, while in the base layer of composition 1-2, these mass ratios were changed to 0.25:0.75:2. In other words, the mass ratio of phenyl groups (cyclic conjugated functional groups) and vinyl groups (reactive functional groups) contained in the base layer is 1:1 in composition 1-1 and 1:3 in composition 1-2.

[0070] [Table 2]

[0071] The modified silicones used in the lubricating layer were all manufactured by Shin-Etsu Chemical Co., Ltd., and in configurations 1-1 and 1-2, a double-ended phenol-modified silicone and a double-ended carboxy-modified silicone were used in a mass ratio of 1:1. Both configurations 1-1 and 1-2 were then diluted with methyl ethyl ketone (7.5 volume percent concentration) so that the modified silicone contained in the lubricating layer was 22.5 volume percent.

[0072] Figure 11(A) shows the measurement results of the weather resistance test for configuration 1-1. Figure 11(B) shows the measurement results of the weather resistance test for configuration 1-2. The water-repellent films of configurations 1-1 and 1-2 maintain the same level of slip resistance as configuration 1 (up to 500 hours after the weather resistance test). [Explanation of Symbols]

[0073] 10... synovial membrane 12. Glass substrate 14. Base layer 14A··phenyl group 14B · Vinyl base 16...Lubricating layer 40. Liquids that are prone to sliding

Claims

1. It comprises a base layer formed on a substrate and a lubricating layer held in 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 that can be covalently bonded to the reactive functional groups of the base layer. A portion of the reactive functional groups in the base layer and a portion of the reactive functional groups in the lubricating layer are covalently bonded. The base layer contains cyclic conjugated functional groups modified on the surface of the substrate, The lubricating layer is δ ＋ The polymer contains charged hydrogen atoms, A portion of the cyclic conjugated functional groups of the base layer and the δ of the lubricating layer ＋ A hydrophobic film characterized by π-electron interaction between some of the charged hydrogen atoms and the electrons.

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

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

4. The lubricating layer has the reactive functional group and the δ ＋ The hydrophobic film according to claim 1, which is a modified silicone containing charged hydrogen atoms.

5. The reactive functional group of the base layer is at least one functional group selected from the group consisting of vinyl group, acrylic group, methacrylic group, carboxyl group, amino group, hydroxyl group, and epoxy group. The cyclic conjugated functional group of the base layer is a phenyl group. The hydrophobic film according to claim 1.

6. The reactive functional group of the lubricating layer is at least one functional group selected from the group consisting of carboxyl group, vinyl group, acrylic group, methacrylic group, amino group, hydroxyl group, and epoxy group, and the δ ＋ The hydrophobic film according to claim 1, wherein the charged hydrogen atom is part of at least one functional group selected from the group consisting of a carboxyl group, a phenol group, and a hydroxyl group.

7. The hydrophobic film according to claim 1, wherein the mass ratio of the cyclic conjugated functional group component of the base layer to the reactive functional group component of the base layer is 1:1 to 1:

3.

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

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