KR102604894B1 - Hydrophobic coating layer and manufacturing method of the same - Google Patents

Abstract

The present invention relates to a hydrophobic coating layer and a method of manufacturing the same. The hydrophobic coating layer according to an embodiment of the present invention is a composition prepared by dispersing hydrophobically modified silica particles in a solvent having a relative dielectric constant of 10 to 80 on a predetermined substrate. It is formed by coating, and includes a smooth layer formed on a substrate and having a first surface roughness, and an uneven layer formed on the smooth layer and having a second surface roughness that is relatively larger than the first surface roughness.
A method for producing a hydrophobic coating layer according to another embodiment of the present invention includes preparing silica particles, modifying the surface of the silica particles using a hydrophobic silane coupling agent, and dispersing the silica particles in a dispersion solvent having a relative dielectric constant of 10 to 80. Preparing a composition by dispersing, preparing a substrate, and applying the composition on the substrate to form a smooth layer having a first surface roughness and an uneven layer formed on the smooth layer and having a second surface roughness greater than the first surface roughness. It includes preparing a coating layer comprising:

Description

Hydrophobic coating layer and its manufacturing method {HYDROPHOBIC COATING LAYER AND MANUFACTURING METHOD OF THE SAME}

The present invention relates to a hydrophobic coating layer and a method for producing the same.

Hydrophobic surface manufacturing technology is widely used across various industrial fields as it can protect materials from moisture and produce effects such as preventing oxidation of materials, preventing stains, reducing frictional resistance, and self-cleaning.

In general, methods for reducing surface energy and forming fine irregularities on the surface to increase surface roughness are known as methods for hydrophobic surfaces.

It is known that one of the conventional methods of lowering the surface energy to produce a hydrophobic surface is to use fluorine-based compounds. However, fluorine-based compounds are expensive for industrial use, making them less economical, accumulating in living organisms, and destroying the environment. There was.

In addition, methods such as surface lithography technology and vertical alignment of nanotubes/nanofibers are known as conventional methods to increase surface roughness to produce a hydrophobic surface, but these methods are difficult to manufacture in large areas and have high processing costs. It was expensive, and the environment and conditions for the process were difficult.

Meanwhile, the production of a surface that is both hydrophobic and highly transparent is receiving a lot of attention as it can be applied in various fields such as solar cell panels, lenses, and windows.

However, when the surface roughness was increased to produce a surface with higher hydrophobicity, there was a problem of decreased transparency due to fine irregularities on the surface, and when the surface roughness was lowered to further increase transparency, there was a problem where the hydrophobicity of the surface decreased.

Republic of Korea Patent Publication No. 10-1406116, registered on June 3, 2014 Republic of Korea Patent Publication No. 10-2016-0060913, published on May 31, 2016

The purpose of the present invention is to solve the above problems. Silica particles dispersed in a dispersion solvent and surface modified with a hydrophobic silane coupling agent can be used to form a coating layer having high hydrophobicity and excellent transparency. The object is to provide a hydrophobic coating layer manufactured by applying a composition containing the same and a method for manufacturing the same.

The object of the present invention is not limited to the object mentioned above, and other objects not mentioned can be clearly understood from the description below.

In order to achieve the above-described object, the present invention relates to a hydrophobic coating layer and a method for manufacturing the same. The hydrophobic coating layer according to an embodiment of the present invention is prepared by dispersing hydrophobically modified silica particles in a solvent having a relative dielectric constant of 10 to 80. It is formed by applying the manufactured composition onto a predetermined substrate, a smooth layer formed on the substrate and having a first surface roughness, and an uneven layer formed on the smooth layer and having a second surface roughness that is relatively larger than the first surface roughness. Includes.

In order to achieve the above-described object, a method of manufacturing a hydrophobic coating layer according to another embodiment of the present invention includes preparing silica particles, modifying the surface of the silica particles using a hydrophobic silane coupling agent, and converting the silica particles to a relative dielectric constant. Preparing the composition by dispersing it in a dispersion solvent of 10 to 80 degrees, preparing a substrate, and applying the composition on the substrate to form a smooth layer having a first surface roughness and a surface roughness greater than the first surface roughness on the smooth layer. 2. It includes manufacturing a coating layer including an uneven layer with surface roughness.

The hydrophobic coating layer and its manufacturing method according to an embodiment of the present invention with the above-described configuration can be expected to have the following effects.

By using silica particles whose surface has been modified with a hydrophobic silane coupling agent, it is possible to manufacture a coating layer that has both excellent hydrophobicity and transparency without using fluorine-based materials.

By using the composition on a substrate to sequentially form a smooth layer with a first surface roughness and an uneven layer with a second surface roughness that is relatively larger than the first surface roughness, there is no need for a difficult process environment or conditions. It is possible to simply manufacture a coating layer with excellent hydrophobicity and high transparency.

1 is a flowchart showing the procedure for manufacturing a hydrophobic coating layer according to another embodiment of the present invention.
Figure 2 is a diagram for explaining a method of manufacturing a hydrophobic coating layer according to another embodiment of the present invention.
Figure 3 is a diagram showing the results of analysis of the average diameter of aggregated silica particles according to the reference example.
Figure 4 is a diagram showing the results of analysis of the average diameter of aggregated silica particles according to the reference example.
Figure 5a is a diagram showing the contact angle measurement results according to Test Example 1 of the coating layer manufactured according to Example 1.
Figure 5b is a diagram showing the contact angle measurement results according to Test Example 1 of the coating layer prepared according to Example 3.
Figure 5c is a diagram showing the contact angle measurement results according to Test Example 1 of the coating layer prepared according to Example 5.
Figure 5d is a diagram showing the contact angle measurement results according to Test Example 1 of the coating layer prepared according to Example 6.
Figures 6a to 6c are diagrams showing the results of transmittance measurement according to Test Example 2.
Figures 7a and 7b are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Example 1.
8A to 8B are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Example 2.
9A to 9B are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Example 3.
10A to 10B are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Example 4.
11A to 11B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Example 9.
Figures 12a to 12b are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Comparative Example 1.
Figures 13a to 13b are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Comparative Example 4.
Figures 14a to 14b are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Comparative Example 5.
Figures 15a to 15b are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Comparative Example 6.
Figures 16a to 16b are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Comparative Example 7.
Figures 17a to 17b are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Example 1.
Figures 18a to 18b are views showing the results of scanning electron microscopy analysis according to Test Example 3 of the coating layer prepared according to Example 3.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and will be implemented in various different forms, but the present embodiments only serve to ensure that the disclosure of the present invention is complete, and those skilled in the art It is provided to fully inform the user of the scope of the invention. Meanwhile, the terms used in this specification are for describing embodiments and are not intended to limit the present invention. As used herein, singular forms also include plural forms, unless specifically stated otherwise in the context.

A method of manufacturing a hydrophobic coating layer according to another embodiment of the present invention relates to a method of manufacturing a hydrophobic coating layer according to an embodiment of the present invention, and time-series performance steps for manufacturing a hydrophobic coating layer according to an embodiment of the present invention. includes them.

For convenience of explanation, when describing the hydrophobic coating layer and its manufacturing method according to the embodiments of the present invention, substantially the same components are indicated by matching reference numerals and repeated descriptions are omitted.

The surface roughness described in the specification of the present invention may mean the degree to which irregularities are formed on the surface, and may mean at least one of the parameters for surface roughness commonly used in the relevant technical field, for example, the arithmetic mean. It may mean at least one of illuminance (R _a ), maximum height illuminance (R _max ), and 10-point average illuminance (R _z ).

Referring to Figure 1, the method for producing a hydrophobic coating layer according to another embodiment of the present invention includes a particle preparation step (S100), a surface modification step (S200), a composition preparation step (S300), and a coating layer preparation step (S400). .

Referring to FIG. 2, the hydrophobic coating layer 10 according to an embodiment of the present invention includes a smooth layer 11 and an uneven layer 12.

First, prepare silica particles (S100).

The diameter of the silica particles prepared in the particle preparation step (S100) may be 1 to 1000 nm, preferably 1 to 400 nm, and more preferably 1 to 5 nm.

If the diameter of the silica particles prepared in the particle preparation step (S100) is less than 1 nm, the size of the silica particles may be too small and the surface roughness of the coating layer prepared in the coating layer manufacturing step (S400) may be low.

If the diameter of the silica particles prepared in the particle preparation step (S100) exceeds 1000 nm, the diameter of the silica particles is too large and the area where the silica particles contact the substrate 20 when forming the coating layer 10 in the coating layer manufacturing step (S400) Otherwise, the binding force of the silica particles to the substrate 20 may decrease, and the transparency of the hydrophobic coating layer 10 manufactured by the method for manufacturing a hydrophobic coating layer according to another embodiment of the present invention may decrease.

The particle preparation step (S100) may be a step of synthesizing silica particles from a silica precursor using a sol-gel process. More specifically, a mixed solution is prepared by mixing a silica precursor and alcohol, and ammonia water is mixed into the prepared mixed solution to form silica particles. This may be a step of synthesizing particles.

Here, the silica precursor is not limited as long as it is commonly used in the synthesis of silica particles using a sol-gel process, and includes, for example, tetra ethoxy silane, methyl trimethoxy silane, and methyl triethylene. It may contain at least one selected from methyl triethoxy silane.

Here, the alcohol may include at least one selected from methanol, ethanol, propanol, and butanol, and may preferably be ethanol.

In addition, here, the ammonia water may be mixed into the mixed solution as a base catalyst in the synthesis of silica particles, the pH value of the mixed solution can be adjusted depending on the mixed amount of ammonia water, and the silica particles according to the adjusted pH value. The diameter of can be changed.

At this time, the pH value of the mixed solution, which is adjusted as the ammonia water is mixed, may be 10 to 13, and the pH value of the mixed solution is adjusted to 10 to 13, so that the silica particles prepared in the particle preparation step (S100) are 1 to 1000 nm. It can have a diameter of

The particle preparation step (S100) may further include the step of purifying the silica particles from the mixed solution when preparing a mixed solution by mixing a silica precursor and an alcohol and mixing ammonia water into the prepared mixed solution to synthesize silica particles. It is not limited to this, and silica particles can be prepared in the form of dispersed silica particles synthesized in the mixed solution without purifying the silica particles from the mixed solution.

If the particle preparation step (S100) further includes the step of purifying silica particles from the mixed solution, purification of silica particles can generally be performed by separating the reaction product from the reaction solution, for example, using a centrifuge. can be used.

The surface of the silica particles prepared in the particle preparation step (S100) is modified (S200) using a hydrophobic silane coupling agent.

The hydrophobic silane coupling agent used in the surface modification step (S200) may be for modifying the surface of the silica particles to be hydrophobic, and may include 3-aminopropyl triethoxysilane, hexadecyltrimethoxysilane ( It may include at least one selected from hexadecyltrimethoxysilane) and 3-trimethoxysilylpropyl methacrylate (3-Methacryloxypropyl trimethoxysilane).

The surface modification step (S200) may be a step of modifying the surface of the silica particles to be hydrophobic by reacting the silica particles prepared in the particle preparation step (S100) with a hydrophobic silane coupling agent.

The surface modification step (S200) may be a step of chemically bonding the hydrophobic silane coupling agent to the silica particles prepared in the particle preparation step (S100) by reacting the silica particles prepared in the particle preparation step (S100) with the hydrophobic silane coupling agent. there is.

In the surface modification step (S200), when the silica particles prepared in the particle preparation step (S100) are prepared in a dispersed form in a mixed solution, the silica particles are reacted with the hydrophobic silane coupling agent by mixing the hydrophobic silane coupling agent in the mixed solution. This may be a step of modifying the surface of the particle.

At this time, the surface modification step (S200) may further include purifying the surface-modified silica particles from the mixed solution and drying the purified silica particles, and the method of purifying the silica particles from the mixed solution is a typical method. A method of purifying the reaction product from the reaction solution can be used, for example, a method using a centrifuge can be used.

A composition is prepared by dispersing the silica particles obtained in the surface modification step (S200) in a dispersion solvent (S300).

The composition manufacturing step (S300) may be to prepare a composition by mixing the dispersion solvent and the silica particles obtained in the surface modification step (S200).

The composition prepared in the composition manufacturing step (S300) may include a dispersion solvent and silica particles dispersed in the dispersion solvent.

If silica particles are dispersed in the dispersion solvent during the composition manufacturing step (S300), the silica particles may aggregate within the dispersion solvent, and the average diameter of the silica particles aggregated within the dispersion solvent may be 100 nm to 5 ㎛. there is.

If the average diameter of the silica particles aggregated in the dispersion solvent of the composition prepared in the composition manufacturing step (S300) is less than 100 nm, the surface roughness of the coating layer 10 prepared in the coating layer manufacturing step (S400) may be low.

If the average diameter of the aggregated silica particles in the dispersion solvent of the composition prepared in the composition manufacturing step (S300) exceeds 5 ㎛, the specific surface area of the aggregated silica particles is relatively reduced, thereby forming the coating layer (10) in the coating layer manufacturing step (S400). When formed, the area in which the aggregated silica particles contact the substrate 20 becomes smaller, so the binding force of the silica particles to the substrate 20 may decrease.

That is, if the average diameter of the silica particles aggregated in the dispersion solvent of the composition prepared in the composition manufacturing step (S300) exceeds 5 ㎛, the aggregated silica particles are not firmly bonded to the substrate 20 and are separated from the substrate 20. As it may come off, the coverage may decrease and the durability of the coating layer 10 may decrease.

In addition, if the average diameter of the silica particles aggregated in the dispersion solvent of the composition prepared in the composition manufacturing step (S300) exceeds 5 ㎛, the surface roughness of the coating layer 10 prepared in the coating layer manufacturing step (S400) becomes too large. The transparency of the coating layer 10 may decrease.

Meanwhile, the 'coverage' described in the specification of the present application refers to the composition applied to the surface of the substrate 20 when manufacturing the coating layer 10 by applying the composition to the surface of the substrate 20 in the coating layer manufacturing step (S400). This may mean the ratio at which the coating layer 10 is formed relative to the area covered.

Preferably, the average diameter of the silica particles aggregated in the dispersion solvent of the composition prepared in the composition manufacturing step (S300) may be 125 nm to 3.7 ㎛, 155 nm to 1020 nm, or 165 nm to 1020 nm. and may be 190 to 1017 nm, 270 to 1017 nm, 307 to 1017 nm, 270 to 476 nm, and 307 to 476 nm.

The degree of cohesion of silica particles dispersed in the dispersion solvent of the composition prepared in the composition manufacturing step (S300) may vary depending on the relative dielectric constant of the dispersion solvent. As the relative dielectric constant of the dispersion solvent increases, the degree of aggregation of silica particles may increase. .

In other words, as the relative dielectric constant of the dispersion solvent increases, the average diameter of the silica particles aggregated within the dispersion solvent may increase.

In the composition manufacturing step (S300), the relative dielectric constant of the dispersion solvent in which the silica particles are dispersed may be 10 to 80.

If the relative dielectric constant of the dispersion solvent is less than 10 in the composition manufacturing step (S300), the degree of cohesion of the silica particles in the dispersion solvent is too low, so that unevenness is smooth on the coating layer 10 when manufacturing the coating layer 10 in the coating layer manufacturing step (S400) to be described later. If it is not formed properly, the surface roughness may decrease and hydrophobicity may decrease.

If the relative dielectric constant of the dispersion solvent exceeds 80 in the composition manufacturing step (S300), the silica particles are excessively aggregated in the dispersion solvent, and the average diameter of the aggregated silica particles becomes too large, causing the specific surface area to decrease, leading to a coating layer manufacturing step (S400) to be described later. When manufacturing the coating layer 10, the aggregated silica particles may not sufficiently contact the substrate 20, may not be firmly bonded, and may separate from the substrate 20.

That is, if the relative dielectric constant of the dispersion solvent exceeds 80 in the composition manufacturing step (S300), the coverage rate, which is the ratio of the formation of the coating layer 10 to the area on which the composition is applied to the surface of the substrate 20, may decrease, The durability of the coating layer 10 may be reduced.

Preferably, the relative dielectric constant of the dispersion solvent in which the silica particles are dispersed during the preparation of the composition in the composition manufacturing step (S300) may be 17 to 72, 19 to 60, 20 to 60, and 24 to 60 days. It can be 28 to 60, it can be 28 to 48, it can be 37 to 48.

The dispersion solvent in which the silica particles are dispersed during the preparation of the composition in the composition manufacturing step (S300) is not limited as long as it has a relative dielectric constant of 10 to 80, but at least one selected from ethanol, 1-propanol, 2-propanol, butanol, and water. It may include

Preferably, the dispersion solvent in which the silica particles are dispersed during the composition manufacturing step (S300) may include ethanol and water.

The composition manufacturing step (S300) may be to prepare a composition by dispersing more than 0.5 parts by weight but less than 2 parts by weight of the silica particles obtained in the surface modification step (S200) in 100 parts by weight of a dispersion solvent.

That is, the composition manufacturing step (S300) may be a step of preparing a composition containing 100 parts by weight of the dispersion solvent and more than 0.5 parts by weight but less than 2 parts by weight of silica particles obtained in the surface modification step (S200).

If the silica particles included in the composition prepared in the composition manufacturing step (S300) are 0.5 parts by weight or less, the amount of silica particles coated on the substrate 20 is insufficient when forming the coating layer 10 in the coating layer manufacturing step (S400). Since the entire surface of the substrate 20 is not coated, coverage may decrease.

If the silica particles contained in the composition prepared in the composition manufacturing step (S300) are 2 parts by weight or more, the amount of silica particles coated on the substrate 20 is excessive when forming the coating layer 10 in the coating layer manufacturing step (S400). The transparency of the coating layer 10 may decrease.

A substrate 20 is prepared, and the coating layer 10 is prepared by applying the composition prepared in the composition preparation step (S300) on the substrate 20 (S400).

In the coating layer manufacturing step (S400), the coating layer 10 is manufactured by applying the composition prepared in the composition manufacturing step (S300) on the substrate 20 and drying it to evaporate the dispersion solvent contained in the composition to form the coating layer 10. This may be a step.

That is, when the composition prepared in the composition manufacturing step (S300) is applied and dried on the substrate 20 in the coating layer manufacturing step (S400), the dispersion solvent contained in the composition is evaporated and the silica particles dispersed in the dispersion solvent are transferred to the substrate (20). ) The coating layer 10 can be manufactured by being combined with and coated.

The coating layer manufacturing step (S400) may be a step of manufacturing the coating layer 10 by applying the composition prepared in the composition manufacturing step (S300) to the surface of the substrate 20.

The coating layer manufacturing step (S400) may be a step of forming the coating layer 10 on the substrate 20 by applying the composition prepared in the composition manufacturing step (S300) to the surface of the substrate 20.

The coating layer manufacturing step (S400) may be a step of forming a coating layer 10 having a predetermined surface roughness on the substrate 20 by applying the composition prepared in the composition manufacturing step (S300) to the surface of the substrate 20.

In the coating layer manufacturing step (S400), the composition prepared in the composition manufacturing step (S300) is applied to the surface of the substrate 20 to form a coating layer 10 having an arithmetic average roughness (R _a ) of 0.1 to 1 ㎛ on the substrate 20. It may be a stage of forming.

If the arithmetic average roughness of the coating layer 10 formed in the coating layer manufacturing step (S400) is less than 0.1 ㎛, the surface roughness of the coating layer 10 may be too low and the hydrophobicity of the coating layer 10 may decrease, and if it exceeds 1 ㎛, the coating layer ( If the surface roughness of 10) is too large, the transparency of the coating layer 10 may decrease.

Preferably, the coating layer manufacturing step (S400) is a step of forming a coating layer (10) having an arithmetic mean roughness (R _a ) of 0.12 to 0.93 ㎛ on the substrate (20) by applying the composition prepared in the composition manufacturing step (S300). It may be a step of forming a coating layer 10 having an arithmetic average roughness (R _a ) of 0.12 to 0.9 ㎛, and a step of forming a coating layer 10 having an arithmetic average roughness (R _a ) of 0.19 to 0.83 ㎛. It may be a step of forming the coating layer 10 having an arithmetic average roughness (R _a ) of 0.2 to 0.8 ㎛.

The coating layer manufacturing step (S400) may be a step of forming a coating layer 10 having a contact angle of 120 to 180° on the substrate 20 by applying the composition prepared in the composition manufacturing step (S300) to the surface of the substrate 20. there is.

Preferably, the coating layer manufacturing step (S400) involves applying the composition prepared in the composition manufacturing step (S300) to the surface of the substrate 20 to form a coating layer 10 having a contact angle of 125 to 180° on the substrate 20. It may be a step of forming a coating layer 10 having a contact angle of 135 to 180°, and it may be a step of forming a coating layer 10 having a contact angle of 137 to 180°, and a coating layer of 139 to 180° ( 10) may be the forming step.

More preferably, in the coating layer manufacturing step (S400), the composition prepared in the composition manufacturing step (S300) is applied to the surface of the substrate 20 to form a coating layer 10 having a contact angle of 144 to 180° on the substrate 20. It may be a step of forming a coating layer 10 with an angle of 150 to 180°.

When applying the composition prepared in the composition manufacturing step (S300) on the substrate 20 in the coating layer manufacturing step (S400), the temperature of the applied composition may be 25°C or more and less than 70°C.

When coating the composition prepared in the composition preparation step (S300) on the substrate 20 in the coating layer preparation step (S400), if the temperature of the composition to be coated is less than 25° C., the rate at which the dispersion solvent evaporates is too slow, and other embodiments of the present invention The productivity of the hydrophobic coating layer 10 manufactured according to the method for manufacturing the hydrophobic coating layer according to the example may be reduced.

Meanwhile, in the coating layer manufacturing step (S400), the composition prepared in the composition manufacturing step (S300) is applied to the substrate 20 and dried to evaporate the dispersion solvent contained in the composition to form the coating layer 10. A coating layer ( A plurality of microcracks may be formed in 10), and as the number of interfaces between cracks formed in the coating layer 10 increases, the surface roughness of the coating layer 10 may increase.

When coating the composition prepared in the composition manufacturing step (S300) on the substrate 20 in the coating layer manufacturing step (S400), if the temperature of the composition to be coated is 70° C. or higher, the rate at which the dispersion solvent evaporates is too fast and the coating layer (10) The number of microcracks formed may be reduced, and accordingly, the surface roughness of the coating layer 10 may be lowered and the hydrophobicity of the coating layer 10 may be reduced.

The coating layer manufacturing step (S400) may be to form the coating layer 10 by applying a composition on the substrate 20 using a brush having a predetermined roughness.

Here, forming the coating layer 10 by applying the composition on the substrate 20 using a brush may mean forming the coating layer 10 by brushing the composition on the substrate 20 using a brush. .

In the coating layer manufacturing step (S400), the coating layer 10 is formed by brushing the composition on the substrate 20 at least once, preferably 1 to 5 times, more preferably 1 to 4 times, and even more preferably 2 times. This may be a step.

The coating layer manufacturing step (S400) may include a substrate preparation step (S410), a smooth layer forming step (S420), and an uneven layer forming step (S430).

The substrate preparation step (S410) may be a step of preparing the substrate 20.

The substrate 20 prepared in the substrate preparation step (S410) is not limited as long as it is made of a material commonly used in fields requiring a hydrophobic surface, for example, polyethylene terephthalate (PET), glass. and at least one selected from metals.

The smooth layer forming step (S420) forms a smooth layer 11 having a first surface roughness by applying the composition prepared in the composition manufacturing step (S300) onto the substrate 20 prepared in the substrate preparation step (S410). It may be a step.

The smooth layer forming step (S420) is performed by applying the composition prepared in the composition manufacturing step (S300) onto the substrate 20 prepared in the substrate preparation step (S410) to form a smooth layer 11 having a first surface roughness. This may be a step of manufacturing the smooth layer 11.

The smooth layer forming step (S420) forms a smooth layer 11 having a relatively lower surface roughness than the uneven layer 12 formed in the uneven layer forming step (S430), thereby forming the coating layer 10 in the coating layer manufacturing step (S400). This may be a step to ensure that the coating layer 10 is formed uniformly throughout the surface of the substrate 20 on which the coating layer 10 is to be formed, without any areas where the coating layer 10 is not formed.

The smooth layer forming step (S420) may be a step of forming the smooth layer 11 by applying a composition on the substrate 20 using a first brush 30 having a first roughness.

Here, forming a smooth layer 11 by applying the composition on the substrate 20 using the first brush 30 means forming a smooth layer by brushing the composition on the substrate 20 using the first brush 30. It may mean forming (11).

The uneven layer forming step (S430) applies the composition prepared in the composition manufacturing step (S300) onto the smooth layer 11 formed in the smooth layer forming step (S420) to produce a second surface roughness that is relatively larger than the first surface roughness. It may be a step of forming the uneven layer 12 having.

The uneven layer forming step (S430) is formed in the coating layer manufacturing step (S400) by forming the uneven layer 12 having a second surface roughness that is relatively larger than the smooth layer 11 formed in the smooth layer forming step (S420). This may be a step to increase the surface roughness of the coating layer 10.

The uneven layer forming step (S430) may be a step of forming the uneven layer 12 by applying a composition on the smooth layer 11 using a second brush 40 having a second roughness that is relatively larger than the first roughness. there is.

Here, forming the uneven layer 12 by applying the composition on the smooth layer 11 using the second brush 40 means brushing the composition on the smooth layer 11 using the second brush 40. This may mean forming the uneven layer 12.

In the uneven layer forming step (S430), the uneven layer 12 is formed on the smooth layer 11 using the second brush 40 having a relatively larger roughness than the first brush 30, thereby performing the coating layer manufacturing step (S400). ) The coating layer 10 formed may have a greater surface roughness.

That is, by forming the uneven layer 12 in the uneven layer forming step (S430), the coating layer 10 can have a greater surface roughness, so that the coating layer 10 manufactured in the coating layer manufacturing step (S400) can have greater hydrophobicity. there is.

Meanwhile, the first brush 30 and the second brush 40 are provided on the grip handles 31 and 41 and the lower surfaces of the grip handles 31 and 41, respectively, that the user can grip, so that the user can apply them to the coated object. It may include a plurality of brush bristles 32 and 42 that are contacted with the coating liquid for brushing.

At this time, the body to be coated may be the substrate 20.

The fact that the second roughness, which is the roughness of the second brush 40, is greater than the first roughness, which is the roughness of the first brush 30, means that the brush bristles 42 of the second brush 40 are the bristles of the first brush 30. This may mean that mechanical deformation is more difficult to achieve when an external force is applied than (32), and the brush bristles 42 of the second brush 40 are stiffer than the brush bristles 32 of the first brush 30 ( This may mean that the stiffness is large, and that the brush bristles 42 of the second brush 40 have a greater Young's modulus than the brush bristles 32 of the first brush 30. .

In addition, the fact that the second roughness, which is the roughness of the second brush 40, is greater than the first roughness, which is the roughness of the first brush 30, means that the brush bristles ( This means that the density of the brush bristles 42, which is the number of 42), is smaller than the density of the brush bristles 32, which is the number of brush bristles 32, relative to the area of the lower surface of the grip handle 31 of the first brush 30. It may be.

The uneven layer forming step (S430) may be a step of forming the uneven layer 12 having a relatively larger arithmetic mean roughness (R _a ) than the smooth layer 11 formed in the smooth layer forming step (S420).

That is, the uneven layer 12 formed in the uneven layer forming step (S430) may have a relatively greater arithmetic mean roughness (R _a ) than the smooth layer 11 formed in the smooth layer forming step (S420).

The arithmetic average roughness (R _a ) of the smooth layer 11 formed in the smooth layer forming step (S420) may be 0.1 to 0.3 ㎛.

If the arithmetic average roughness (R _a ) of the smooth layer 11 formed in the smooth layer forming step (S420) is less than 0.1 ㎛, the hydrophobicity of the hydrophobic coating layer 10 manufactured according to an embodiment of the present invention may be reduced, and the hydrophobicity of the hydrophobic coating layer 10 manufactured according to an embodiment of the present invention may be reduced, and the If it exceeds ㎛, the surface roughness of the smooth layer 11 is large and the uneven layer 12 may not be formed smoothly on the smooth layer 11.

Preferably, the arithmetic mean roughness (R _a ) of the smooth layer 11 formed in the smooth layer forming step (S420) may be 0.12 to 0.25 ㎛, or 0.19 to 0.21 ㎛.

The arithmetic average roughness (R _a ) of the uneven layer 12 formed in the uneven layer forming step (S430) may be 0.6 to 1 ㎛.

If the arithmetic average roughness (R _a ) of the uneven layer 12 formed in the uneven layer forming step (S430) is less than 0.6 ㎛, the surface roughness of the uneven layer 12 is too small and the hydrophobicity manufactured according to an embodiment of the present invention The hydrophobicity of the coating layer 10 may decrease, and if it exceeds 1 ㎛, the surface roughness of the uneven layer 12 may be too large, and the transparency of the hydrophobic coating layer 10 manufactured according to an embodiment of the present invention may decrease.

Preferably, the arithmetic mean roughness (R _a ) of the uneven layer 12 formed in the uneven layer forming step (S430) may be 0.68 to 0.9 ㎛, 0.7 to 0.85 ㎛, and 0.75 to 0.83 ㎛. .

Referring to FIG. 2, in the smooth layer forming step (S420), the smooth layer 11 is formed on the substrate 20 using the first brush 30, and in the uneven layer forming step (S430), the second brush ( By forming the uneven layer 12 on the smooth layer 11 using 40), the hydrophobic coating layer 10 including the smooth layer 11 and the uneven layer 12 can be formed.

<Example 1>

1. Preparation of silica particles

First, tetraethoxysilane, a silica precursor (Product name: Tetraethylorthosilicate (TEOS, 98%), Manufacturer: Sigama-Aldrich) and ethanol, an alcohol (Product name: Anhydrous ethyl alcohol (ethanol, 99.9%), Manufacturer: Daejeong Chemical) A mixed solution was prepared by mixing, and ammonia water was mixed into the prepared mixed solution to synthesize silica particles.

In more detail, a mixed solution was prepared by mixing 50.02 ml of ethanol and 3 ml of tetraethoxysilane, and the pH of the mixed solution was adjusted to 10.912 by mixing ammonia water with a concentration of 0.46M into the prepared mixed solution to synthesize silica particles. By doing this, silica particles dispersed in the mixed solution were prepared.

2. Surface modification of silica particles

1. 0.51 ml of hexadecyltrimethoxysilane, a hydrophobic silane coupling agent, was mixed with the mixed solution obtained in the preparation of silica particles and stirred at 300 rpm for 2 hours. Afterwards, the surface-modified silica particles were purified from the mixed solution using a centrifuge, and the purified silica particles were dried at 70°C for 24 hours.

3. Preparation of the composition

2. A composition was prepared by mixing 1 part by weight of silica particles obtained from surface modification of silica particles with 100 parts by weight of dispersion solvent. At this time, the dispersion solvent was a mixed solution prepared by mixing 56.2% by volume of ethanol (Product name: Anhydrous ethyl alcohol (ethanol, 99.9%), Manufacturer: Daejeong Chemical) and 43.8% by volume of water.

4. Preparation of coating layer

A substrate 20 was prepared, and the coating layer 10 was prepared by applying the composition prepared in step 3. Preparation of the composition on the substrate 20. At this time, a polyethylene terephthalate film with a thickness of 125 ㎛ was used as the substrate 20, and the temperature of the applied composition was 25°C.

More specifically, the composition prepared in step 3. Preparation of the composition is brushed on the substrate 20 with a first brush 30 having a first roughness to form a smooth layer 11, and the smooth layer 11 is formed, and the composition is brushed on the substrate 20 with a first brush 30 having a first roughness, and the composition is brushed on the substrate 20 with a first brush 30 having a first roughness, which is relatively larger than the first roughness. The coating layer 10 was manufactured by brushing the composition prepared in step 3. Preparation of composition on the smooth layer 11 using a second brush 40 having a second roughness to form an uneven layer 12.

<Example 2>

The coating layer 10 was manufactured in the same manner as in Example 1. However, 3. In the preparation of the composition, instead of using a mixture of 56.2 vol% ethanol and 43.8 vol% water as a dispersion solvent, a mixture prepared by mixing 92.0 vol% ethanol and 8.0 vol% water was used.

<Example 3>

The coating layer 10 was manufactured in the same manner as in Example 1. However, 4. In forming the coating layer, the composition is brushed on the substrate 20 with the first brush 30 to form a smooth layer 11, and the composition is brushed on the smooth layer 11 with the second brush 40. Instead of forming the coating layer 10 by forming the uneven layer 12, the coating layer 10 was formed by brushing the composition on the substrate 20 twice with the first brush 30.

<Example 4>

The coating layer 10 was manufactured in the same manner as in Example 2. However, 4. In forming the coating layer, the composition is brushed on the substrate 20 with the first brush 30 to form a smooth layer 11, and the composition is brushed on the smooth layer 11 with the second brush 40. Instead of forming the coating layer 10 by forming the uneven layer 12, the coating layer 10 was formed by brushing the composition on the substrate 20 twice with the first brush 30.

<Example 5>

The coating layer 10 was manufactured in the same manner as in Example 1. However, in the formation of the fourth coating layer, a glass substrate 20 with a thickness of 1 mm was used instead of a polyethylene terephthalate film.

<Example 6>

The coating layer 10 was manufactured in the same manner as in Example 1. However, in forming the fourth coating layer, a metal substrate 20 with a thickness of 300 μm was used instead of a polyethylene terephthalate film.

<Example 7>

The coating layer 10 was manufactured in the same manner as in Example 2. However, in the formation of the fourth coating layer, a glass substrate 20 with a thickness of 1 mm was used instead of a polyethylene terephthalate film.

<Example 8>

The coating layer 10 was manufactured in the same manner as in Example 2. However, in forming the fourth coating layer, a metal substrate 20 with a thickness of 300 μm was used instead of a polyethylene terephthalate film.

<Example 9>

The coating layer 10 was manufactured in the same manner as in Example 3. However, in the formation of the fourth coating layer, the temperature of the composition applied when forming the coating layer 10 was set to 40°C, not 25°C.

<Comparative Example 1>

The coating layer 10 was manufactured in the same manner as in Example 1. However, 3. In the preparation of the composition, instead of using a mixed solution prepared by mixing 56.2 vol% ethanol and 43.8 vol% water as a dispersion solvent, a mixed solution prepared by mixing 12.5 vol% ethanol and 87.5 vol% water was used.

<Comparative Example 2>

The coating layer 10 was manufactured in the same manner as Comparative Example 1. However, 4. In the formation of the coating layer, a glass substrate 20 with a thickness of 1 mm was used instead of a polyethylene terephthalate film.

<Comparative Example 3>

The coating layer 10 was manufactured in the same manner as Comparative Example 1. However, 4. In the formation of the coating layer, a metal substrate 20 with a thickness of 300 μm was used instead of a polyethylene terephthalate film.

<Comparative Example 4>

The coating layer 10 was manufactured in the same manner as Comparative Example 1. However, 4. In forming the coating layer, the composition is brushed on the substrate 20 with the first brush 30 to form a smooth layer 11, and the composition is brushed on the smooth layer 11 with the second brush 40. Instead of forming the coating layer 10 by forming the uneven layer 12, the coating layer 10 was formed by brushing the substrate 20 twice with the first brush 30.

<Comparative Example 5>

The coating layer 10 was manufactured in the same manner as in Example 3. However, 3. In preparing the composition, instead of mixing 1 part by weight of silica particles and 100 parts by weight of dispersion solvent, 0.5 parts by weight of silica particles and 100 parts by weight of dispersion solvent were mixed.

<Comparative Example 6>

The coating layer 10 was manufactured in the same manner as in Example 3. However, 3. In preparing the composition, instead of mixing 1 part by weight of silica particles and 100 parts by weight of dispersion solvent, 2 parts by weight of silica particles and 100 parts by weight of dispersion solvent were mixed.

<Comparative Example 7>

The coating layer 10 was manufactured in the same manner as in Example 3. However, in the formation of the 4 coating layer, the temperature of the composition applied when forming the coating layer was set to 70°C, not 25°C.

The manufacturing conditions of the coating layer 10 according to Examples 1 to 9 and Comparative Examples 1 to 7 are summarized in Table 1 below.

Dispersion solvent volume ratio
(ethanol:water) Brush Conditions Substrate type Silica parts by weight composition temperature
(℃) Example 1 56.2:43.8 S/H PET One 25 Example 2 92.0:8.0 S/H PET One 25 Example 3 56.2:43.8 S/S PET One 25 Example 4 92.0:8.0 S/S PET One 25 Example 5 56.2:43.8 S/H glass One 25 Example 6 56.2:43.8 S/H metal One 25 Example 7 92.0:8.0 S/H glass One 25 Example 8 92.0:8.0 S/H metal One 25 Example 9 56.2:43.8 S/S PET One 40 Comparative Example 1 12.5:87.5 S/H PET One 25 Comparative Example 2 12.5:87.5 S/H glass One 25 Comparative Example 3 12.5:87.5 S/H metal One 25 Comparative Example 4 12.5:87.5 S/S PET One 25 Comparative Example 5 56.2:43.8 S/S PET 0.5 25 Comparative Example 6 56.2:43.8 S/S PET 2 25 Comparative Example 7 56.2:43.8 S/S PET One 70

Here, 'dispersion solvent volume ratio' refers to the volume ratio of ethanol and water mixed in the dispersion solvent in which silica particles are dispersed in 3. the production of the composition, and 'substrate type' refers to 4. the substrate to which the composition is applied in forming the coating layer. It refers to the type of (20), and 'silica parts by weight' refers to the parts by weight of silica particles dispersed in 100 parts by weight of the dispersion solvent in the preparation of 3. the composition, and the composition temperature is 4. the weight of the silica particles applied in the formation of the coating layer. This refers to the temperature of the composition.

In addition, 'S/H' in 'brush conditions' is 4. When manufacturing the coating layer 10 by applying the composition on the substrate 20 in the production of the coating layer, the smooth layer 11 is applied with the first brush 30. It means manufacturing the coating layer 10 by forming the uneven layer 12 with the second brush 40 on the smooth layer 11, and 'S/S' refers to manufacturing the composition on the substrate 20. This means forming the coating layer 10 by brushing twice with the first brush 30.

<Reference example>

In the reference example, in order to analyze the degree to which the silica particles obtained from surface modification of silica particles in Example 1 2. were dispersed in a predetermined solvent, the silica particles obtained from 2. surface modification of silica particles in Example 1 were dissolved in a predetermined solvent. The average diameter of the aggregated silica particles when dispersed was measured.

At this time, a dynamic light scattering measuring device (model name: multi-scope, manufactured by K-one) was used to measure the average diameter of the aggregated silica particles, and the average diameter of particles dispersed in the solvent was measured using a dynamic light scattering measuring device. Since this is obvious to those skilled in the art to which the present invention pertains, detailed description will be omitted.

Additionally, ethanol, 1-propanol, 2-propanol, and 1-butanol were used as solvents. In addition, a mixed solution prepared by mixing 92.0 vol% of ethanol and 8.0 vol% of water, a mixed solution prepared by mixing 74.9 vol% of ethanol and 25.1 vol% of water, a mixed solution prepared by mixing 56.2 vol% of ethanol and 43.8 vol% of water, A mixed solution prepared by mixing 35.5 vol% of ethanol and 64.5 vol% of water, and a mixed solution prepared by mixing 12.5 vol% of ethanol and 87.5 vol% of water were used.

The results of the analysis of the average diameter of the aggregated silica particles for the type of solvent used are shown in Table 2 and Figures 3 and 4 below, and the generally known relative dielectric constants for the solvent used are shown in Table 2 below.

solvent used Average diameter of aggregated silica particles
(nm) relative dielectric constant 1-propanol 165.38 20.10 2-propanol 159.04 19.91 1-Butanol 127.45 17.10 ethanol 190.51 24.30 Ethanol:water
(92.0:8.0) 270.33 28.61 Ethanol:water
(74.9:25.1) 307.74 37.84 Ethanol:water
(56.2:43.8) 475.14 47.99 Ethanol:water
(35.5:64.5) 1016.58 59.19 Ethanol:water
(12.5:87.5) 3625.42 71.62

In Table 2, ethanol:water refers to a mixed solution prepared by mixing ethanol and water, and the ratio in parentheses refers to the volume ratio of ethanol and water. For example, in Table 2, ethanol:water (92.0:8.0) refers to a mixture of 92.0% by volume ethanol and 8.0% water.

Referring to Table 2 and Figures 3 and 4, it can be seen that the relatively larger the relative dielectric constant of the solvent used, the larger the average diameter of the aggregated silica particles. This is a result confirming that the greater the relative dielectric constant of the solvent used, the greater the degree to which silica particles are aggregated within the solvent used.

<Test Example 1>

In Test Example 1, the contact angle was measured using water as a measuring solvent to measure the hydrophobicity of the coating layer 10 prepared according to Examples 1 to 9 and Comparative Examples 1 to 7.

In Test Example 1, the contact angle was measured by dropping 8.65 μl of water droplets on the coating layer 10 prepared according to Examples 1 to 9 and Comparative Examples 1 to 7 and using a contact angle meter (model name: FM-40, manufactured by KRUSS). Measured.

In addition, the sliding angle of the coating layer 10 manufactured according to Examples 1, 5, and 6 was also measured.

On the other hand, 'slip angle' may mean the tilt angle at which the liquid begins to flow based on the horizontal bottom surface, and the substrate 20 with the coating layer 10 manufactured according to Examples 1, 5, and 6 is formed. This may mean the tilt angle at which liquid begins to flow when placed on a horizontal floor and tilted.

Figures 5a to 5d and Table 3 below summarize the contact angle measurement results according to Test Example 1.

Figure 5A is a diagram showing the contact angle measurement results of the coating layer prepared according to Example 1, Figure 5B is a diagram showing the contact angle measurement results of the coating layer prepared according to Example 3, and Figure 5C is a diagram showing the contact angle measurement results of the coating layer prepared according to Example 5. This is a diagram showing the contact angle measurement results of the coating layer, and Figure 5D is a diagram showing the contact angle measurement results of the coating layer manufactured according to Example 6.

Contact angle (°) Slip angle (°) Example 1 152.6 0 Example 2 136.6 X Example 3 131.9 X Example 4 125.2 X Example 5 139.4 <5 Example 6 144.7 <5 Example 7 137.1 X Example 8 135.3 X Example 9 129.2 X Comparative Example 1 83.7 X Comparative Example 2 64.2 X Comparative Example 3 81.3 X Comparative Example 4 114.6 X Comparative Example 5 112.1 X Comparative Example 6 130.0 X Comparative Example 7 116.4 X

Referring to Table 3, it can be seen that the contact angle of the coating layer 10 manufactured according to Examples 1 and 2 is higher than the contact angle of the coating layer 10 manufactured according to Comparative Example 1, which is consistent with Examples 1 and 2. This result indicates that the hydrophobicity of the coating layer 10 manufactured according to Comparative Example 1 is greater than that of the coating layer 10 manufactured according to Comparative Example 1.

This is a result confirming that if the relative dielectric constant of the dispersion solvent in which the silica particles are dispersed is too high, the coverage of the coating layer 10 decreases as the silica particles aggregate excessively in the dispersion solvent.

In addition, the contact angle of the coating layer 10 prepared according to Examples 5 and 7 is greater than the contact angle of the coating layer 10 prepared according to Comparative Example 2, and the contact angle of the coating layer 10 prepared according to Examples 6 and 8 is It can be confirmed that the contact angle of the coating layer 10 prepared according to Comparative Example 3 is greater than that of the coating layer 10 prepared according to Examples 3 and 4, and that the contact angle of the coating layer 10 prepared according to Comparative Example 4 is greater than that of These results also confirm that if the relative dielectric constant of the dispersion solvent in which the silica particles are dispersed is too high, the coverage of the coating layer 10 decreases as the silica particles aggregate excessively in the dispersion solvent.

It can be seen that the contact angle of the coating layer 10 prepared according to Example 3 is higher than that of the coating layer 10 prepared according to Comparative Example 5, which means that when the content of silica particles mixed in the dispersion solvent decreases when preparing the composition, When forming the coating layer 10, the silica particles were not uniformly coated on the entire surface of the substrate 20, resulting in a decrease in coverage, which is the rate at which the coating layer 10 is formed on the entire surface of the substrate 20. am.

Meanwhile, it can be confirmed that the contact angle of the coating layer 10 manufactured according to Example 1 and Example 2 is higher than the contact angle of the coating layer 10 manufactured according to Example 3 and Example 4, respectively, which is the second surface roughness This result confirms that when the surface roughness of the coating layer 10 is improved by forming the uneven layer 12 having , the hydrophobicity increases.

It can be confirmed that the contact angle of the coating layer 10 prepared according to Example 3 and Example 9 is higher than the contact angle of the coating layer 10 prepared according to Comparative Example 7, which means that when the composition is applied on the substrate 20, the composition If the temperature is too high, the number of microcracks formed in the coating layer 10 decreases, thereby confirming that the hydrophobicity of the manufactured coating layer 10 decreases.

It can be seen that the sliding angle of the coating layer 10 manufactured according to Examples 1, 5, and 6 is less than 5°, which means that the coating layer 10 manufactured according to Examples 1, 5, and 6 has excellent hydrophobicity. This is a result that can be confirmed. In particular, it can be confirmed that the coating layer 10 manufactured according to Example 1 has a contact angle of 152.6° and a sliding angle of 0°, indicating that it has superhydrophobicity.

<Test Example 2>

Test Example 2 is an experiment to measure the transparency of the coating layer 10 prepared according to Examples 1 to 4 and 9 and the coating layer 10 prepared according to Comparative Examples 1 and 4 to 7.

In Test Example 2, in order to measure transparency, a substrate 20 formed with a coating layer 10 manufactured according to Examples 1 to 4 and 9 and a substrate formed with a coating layer 10 manufactured according to Comparative Examples 1, 4 to 7 ( 20) was measured.

In Test Example 2, the transmittance was measured in the wavelength range of 300 to 800 nm using a UV-Vis spectrophotometer (model name: Optizen pop, manufactured by Mecasys).

The test results are shown in FIGS. 6A to 6C and Table 4.

Transmittance (%) Example 1 81.69 Example 2 90.30 Example 3 82.02 Example 4 89.75 Example 9 83.14 Comparative Example 1 90.04 Comparative Example 4 85.88 Comparative Example 5 88.01 Comparative Example 6 62.56 Comparative Example 7 86.14

Referring to Table 4, it can be seen that the transmittance of the coating layer 10 manufactured according to Examples 1 to 4 and 9 all exceeds 80%, which is the This result confirms that transparency is excellent and that even when the coating layer 10 is formed on the substrate 20 according to an embodiment of the present invention, the decrease in transmittance is not significant.

Referring to Table 4, the coating layer (10) manufactured according to Comparative Example 6 is better than the coating layer (10) manufactured according to Examples 1 to 4 and 9 and the coating layer (10) manufactured according to Comparative Examples 1, 4, 5 and 7. ) can be seen to have the lowest transmittance, which is a result confirming that if the content of silica particles dispersed in the dispersion solvent is too high, the transparency of the coating layer 10 produced decreases.

<Test Example 3>

Test Example 3 is an experiment to analyze the surface of the coating layer 10 according to Examples 1 to 4 and 9 and the coating layer 10 according to Comparative Examples 1, 4, 5 and 7.

In Test Example 3, in order to analyze the surface of the coating layer 10 according to Examples 1 to 4 and 9 and the coating layer 10 according to Comparative Examples 1, 4, 5 and 7, the coating layer according to Examples 1 to 4 and 9 ( 10) and the coating layer 10 according to Comparative Examples 1, 4, 5, and 7 were analyzed using a scanning electron microscope.

The analysis results are shown in Figures 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b, 11a, 11b, 12a, 12b, 13a, 13b, 14a, 14b, 15a, 15b, 16a, 16b, 17a, 17b, 18a and Shown in 18b.

Figures 7A to 7B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Example 1, and Figures 8A to 8B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Example 2, Figures 9A to 9B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Example 3, and Figures 10A to 10B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Example 4, Figures 11A to 11B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Example 9, and Figures 12A to 12B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Comparative Example 1, Figures 13A to 13B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Comparative Example 4, and Figures 14A to 14B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Comparative Example 5, Figures 15A to 15B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Comparative Example 6, and Figures 16A to 16B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Comparative Example 7, Figures 17A to 17B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Example 1, and Figures 18A to 18B are diagrams showing the results of scanning electron microscopy analysis according to Test Example 3 according to Example 3.

First, referring to FIGS. 7A to 7B, 8A to 8B, and 12A to 12B, looking at the coating layer 10 manufactured according to Examples 1 and 2 and the coating layer 10 manufactured according to Comparative Example 1, Examples 1 and 2 It can be seen that the coating layer 10 manufactured according to is formed uniformly overall on the surface of the substrate 20, while the coating layer 10 manufactured according to Comparative Example 1 is formed somewhat uniformly on the substrate 20. Therefore, it can be seen that the coverage is somewhat low. This means that if the dielectric constant of the dispersion solvent in which the silica particles are dispersed is too large, the silica particles are excessively aggregated, and the bonding force between the aggregated silica particles and the substrate 20 decreases, resulting in a poor bonding state. This result confirms that the coverage rate decreases as the aggregated silica particles are separated from the substrate 20 without being maintained.

Referring to FIGS. 9A to 9B, 10A to 10B, and 13A to 13B, looking at the coating layer 10 manufactured according to Examples 3 and 4 and the coating layer 10 manufactured according to Comparative Example 4, according to Examples 3 and 4. While it can be confirmed that the coating layer 10 manufactured is uniformly formed overall on the surface of the substrate 20, the coating layer 10 manufactured according to Comparative Example 4 is not formed somewhat uniformly on the substrate 20. It can be seen that the coverage is somewhat low. This means that if the dielectric constant of the dispersion solvent in which the silica particles are dispersed is too large, the silica particles are excessively aggregated, and the bonding force between the aggregated silica particles and the substrate 20 decreases, making it difficult to maintain the bonded state. This is a result that confirms that the coverage rate decreases as the silica particles that were aggregated and separated from the substrate 20 are detached from the substrate 20.

Looking at the coating layer 10 manufactured according to Examples 3 and 9 and the coating layer 10 manufactured according to Comparative Example 7 with reference to FIGS. 9A to 9B, 11A to 11B, and 16A to 16B, the coating layer 10 manufactured according to Examples 3 and 9 It can be seen that the number of microcracks formed in the coating layer 10 manufactured according to Comparative Example 7 is somewhat smaller than the number of microcracks formed in the coating layer 10 manufactured according to Comparative Example 7. This means that when the coating layer 10 is formed by applying the composition on the substrate 20, if the temperature of the coating composition is too high, the dispersion solvent evaporates too quickly, thereby reducing the number of microcracks formed in the coating layer 10. It is a result.

Looking at the coating layer 10 manufactured according to Example 3 and the coating layer 10 manufactured according to Comparative Example 5 with reference to FIGS. 9A to 9B and 14A to 14B, the hydrophobic coating layer 10 manufactured according to Example 3 is a substrate (20) While it can be confirmed that it is formed uniformly on the entire surface, the coating layer 10 manufactured according to Comparative Example 5 is not formed somewhat uniformly on the substrate 20, and the coverage rate is somewhat low. It can be confirmed that, when the content of silica particles dispersed in the dispersion solvent decreases, the coverage rate, which is the ratio of the formation of the coating layer 10 with respect to the area on which the composition is applied to the surface of the substrate 20, may decrease. It is a result.

Looking at the coating layer 10 manufactured according to Example 1 and the coating layer 10 manufactured according to Example 3 with reference to FIGS. 17A to 17B and 18A to 18B, the coating layer 10 manufactured according to Example 1 was It can be seen that more irregularities were formed than in the coating layer 10 manufactured according to Example 3.

This is by forming a smooth layer 11 using the first brush 30 on the substrate 20 and forming an uneven layer 12 using the second brush 40 on the smooth layer 11, thereby forming a coating layer ( This result confirms that by manufacturing 10), it is possible to manufacture a coating layer 10 with a higher surface roughness than when manufacturing the coating layer 10 using the first brush 30.

<Test Example 4>

In Test Example 4, the surface roughness of the coating layer 10 manufactured according to Examples 1 and 3 was measured.

In Test Example 4, the surface roughness was measured by measuring the arithmetic mean roughness (R _a ) of the coating layer 10 manufactured according to Examples 1 and 3 using a surface profiler (product name: D-300, manufacturer: KLA). -Tencor) was measured three times.

The measurement results are shown in Table 5 below.

Arithmetic average illuminance (㎛) Example 1 1 time 0.798 Episode 2 0.826 3rd time 0.799 average 0.808 Example 3 1 time 0.195 Episode 2 0.200 3rd time 0.204 average 0.200

Referring to Table 5, it can be seen that the arithmetic mean roughness of the coating layer 10 manufactured according to Example 1 is greater than that of the coating layer 10 manufactured according to Example 3. This means that when manufacturing the coating layer 10 by applying the composition on the substrate 20, the smooth layer 11 is formed with the first brush 30 and the second brush is applied on the smooth layer 11. When the uneven layer 12 is formed with the brush 40, the coating layer 10 has a greater surface roughness than when the coating layer 10 is formed by brushing the composition on the substrate 20 twice with the first brush 30. ) is a result that confirms that it can be manufactured.

A person skilled in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the scope of the claims described below rather than the detailed description above, and all changes or modified forms derived from the scope of the claims and their equivalent concepts should be construed as being included in the scope of the present invention.

10: coating layer, 11: smooth layer, 12, uneven layer,
20: substrate,
30: first brush, 31: grip handle, 32: brush bristles,
40: second brush, 41, grip handle, 42: brush bristles,
S100: particle preparation step,
S200: Surface modification step,
S300: Composition manufacturing step,
S400: Coating layer manufacturing step,
S410: Substrate preparation step, S420: Smooth layer forming step, S430: Concave-convex layer forming step.

Claims (9)

Preparing silica particles;
Modifying the surface of the silica particles using a hydrophobic silane coupling agent;
Preparing a composition by dispersing more than 0.5 but less than 2 parts by weight of the silica particles in 100 parts by weight of a dispersion solvent having a relative dielectric constant of 28.61 to 47.99;
Preparing a substrate; and
A smooth layer having a first surface roughness is formed by applying the composition having a temperature of 25° C. to 40° C. on the substrate, and an uneven layer formed on the smooth layer and having a second surface roughness greater than the first surface roughness. Including; manufacturing a coating layer.
Method for producing a phosphorus hydrophobic coating layer. The method of claim 1, wherein the step of manufacturing the coating layer is
Preparing the coating layer having an arithmetic mean roughness of 0.1 to 1 ㎛ and a contact angle of 120 to 180°;
Method for producing a phosphorus hydrophobic coating layer. The method of claim 1, wherein the step of manufacturing the coating layer is
Preparing the substrate;
forming the smooth layer having a relatively lower arithmetic mean roughness than the uneven layer by applying the composition on the substrate using a first brush having a first roughness; and
Applying the composition on the smooth layer using a second brush having a second roughness that is relatively larger than the first roughness to form the uneven layer having an arithmetic mean roughness that is relatively larger than the smooth layer. thing
Method for producing a phosphorus hydrophobic coating layer. delete delete The method of claim 1, wherein the step of preparing the silica particles is
A step of preparing the silica particles with a particle diameter of 1 to 400 nm.
Method for producing a phosphorus hydrophobic coating layer. The method of claim 1, wherein modifying the surface comprises
A step of surface modifying the silica particles using the silane coupling agent containing at least one selected from 3-aminopropyltriethoxysilane, hexadecyltrimethoxysilane, and 3-trimethoxysilylpropyl methacrylate. thing
Method for producing a phosphorus hydrophobic coating layer. A composition prepared by dispersing more than 0.5 but less than 2 parts by weight of silica particles whose surface has been modified using a hydrophobic silane coupling agent in 100 parts by weight of a dispersion solvent having a relative dielectric constant of 28.61 to 47.99, and having a temperature of 25 ℃ or more and 40 ℃ or less, is placed on a given substrate. It is formed by applying,
Comprising a smooth layer formed on the substrate and having a first surface roughness, and an uneven layer formed on the smooth layer and having a second surface roughness that is relatively larger than the first surface roughness.
Phosphorus hydrophobic coating layer. According to clause 8,
An arithmetic mean roughness of 0.1 to 1 ㎛ and a contact angle of 120 to 180°.
Phosphorus hydrophobic coating layer.

Images