KR100776970B1 - A method of ultra water repellent surface formed by a plasma treatment - Google Patents

Abstract

A method for forming an ultra water repellent surface by using a plasma treatment is provided to improve productivity and to reduce remarkably a manufacturing cost by adding a hydrophobic property to a treating target. A treating target installation process is performed to install a treating target at an upper side of an electrode which is installed in an inside of a vacuum chamber(S100). A vacuum forming process is performed to compose the inside of the vacuum chamber as vacuum atmosphere(S200). A plasma generation process is performed to generate plasma by supplying power to the electrode(S300). A surface etching process is performed to etch a surface of the treating target by controlling a time for supplying voltage and power to be supplied to the electrode(S400). A hydrophobic member is inserted into the vacuum chamber in order to be coupled with the surface of the treating target by using the plasma(S500).

Description

A method of ultra water repellent surface formed by a plasma treatment}

1 is a schematic view showing the internal configuration of a vacuum plasma apparatus applied to the method of forming a super water-repellent surface through the plasma treatment according to the present invention.

Figure 2 is a schematic diagram showing the internal configuration of the atmospheric pressure plasma apparatus applied to the method of forming a super water-repellent surface through the plasma treatment according to the present invention.

Figure 3a is a flow chart showing a process performed in a vacuum atmosphere in the method of forming a super water-repellent surface through the plasma treatment according to the present invention.

Figure 3b is a flow chart showing a process carried out in the atmosphere in the super water-repellent surface forming method through the plasma treatment according to the present invention.

Figure 4 is a photograph showing the contact angle of the Teflon surface treated with water according to the method of forming a super water-repellent surface through the plasma treatment according to the present invention.

FIG. 5 is a photograph showing the roughness of the Teflon surface in FIG. 4. FIG.

Figure 6 is a photograph showing the contact angle of the surface treated acrylic water according to the method of forming a super water-repellent surface through the plasma treatment according to the present invention.

7 is a photograph showing the roughness of the acrylic surface in FIG.

FIG. 8 is a photograph showing a contact angle with respect to water after UV irradiation for one week on acrylic of FIG. 6.

Explanation of symbols on the main parts of the drawings

10. Electrode 20. Roller

22. First roller 24. Second roller

30. Power supply 40. Antenna

50. Reaction gas inlet 60. Hydrophobic member inlet

70. Dielectric C. Vacuum Chamber

S100. Workpiece installation step S200. Vacuum forming step

S300. Plasma generating step S400. Surface etching step

S500. Hydrophobicization step. Treated matter

The present invention relates to a method of forming a super water-repellent surface through a plasma treatment to generate a plasma on the surface of the workpiece under vacuum or atmospheric pressure, and then roughly process the bonded hydrophobic member to the surface of the workpiece.

Water repellency refers to a property that is in common with hydrophobicity (인 水性), which has a low affinity for water, and can be observed in everyday life. In other words, when the water droplets fall on the lotus leaf, the leaf does not get wet and the water droplets roll off may be a good example of water repellency.

This phenomenon causes the self-cleaning effect by removing the foreign matter accumulated on the surface of the lotus leaf with water droplets. Scientists have observed this carefully and found that projections of several to several micrometers are formed on the surface of the lotus leaf. On the surface of the projections, it was found that the projections of several tens to hundreds of nm in size were distributed. And, these projections were found to have a contact angle with water of 140 ° or more.

For reference, air has a contact angle of 180 ° with respect to water.

In the 1930s, the researchers began to study the self-cleaning effect and the property that contaminants are not easily adsorbed on the surface.

As part of this research, Korean Patent Publication No. 1996-0033562 discloses a 'hydrophobic coating method and a hydrophobic coating material of silicone rubber'.

Looking briefly, the surface of the silicone rubber is activated and modified by plasma etching to obtain a hydrophilic rubber surface, and the hydrophobic polyurethane coating material is coated on the modified surface by applying a hydrophobic polyurethane coating material after the primer (member for increasing adhesion). The invention is intended to form a surface of a silicone rubber having a thin film that is excellent in printability and anti-slip and has a good feel.

However, the prior art having the configuration as described above has the following problems.

In other words, the workpiece is hydrophobic through various processes such as activation of the surface of the workpiece through plasma etching, primer treatment of the surface of the activated workpiece, and coating of the polyurethane coating material, and coating in the coating process of the polyurethane coating material. There is a problem that is difficult to manage the thickness constant.

In addition, since the size of the workpiece to be applied to the above method is limited, it is not suitable for hydrophobic treatment of the workpiece having a large area, and there is a problem that the defective rate increases.

In addition, even if the workpiece is formed of a material having a hydrophobicity, the polyurethane coating material must be coated, so that manufacturing cost increases, thereby lowering the price competitiveness.

Accordingly, an object of the present invention for solving the above problems is to generate a plasma on the surface of the workpiece under vacuum or atmospheric pressure, and then roughly process the plasma treatment to combine the hydrophobic member on the surface of the workpiece. It is to provide a method of forming a super water-repellent surface through.

Another object of the present invention is to improve the productivity by having a hydrophobicity through the plasma irrespective of the hydrophobicity or hydrophilicity of the workpiece, through the plasma treatment to enable the formation of the workpiece having a large area and uniform surface roughness It is to provide a method of forming a super water-repellent surface.

Method for forming a super water-repellent surface through the plasma treatment according to the present invention for achieving the object as described above comprises the steps of installing the workpiece to install the workpiece on the electrode provided inside the vacuum chamber; A vacuum forming step of forming an inside of the vacuum chamber in a vacuum atmosphere; A plasma generation step of generating a plasma by supplying power to the electrode; A surface etching step of etching the surface of the object by controlling the voltage and power supply time applied to the electrode; Introducing a hydrophobic member into the vacuum chamber and coupling the hydrophobic member to the surface of the object by using a plasma; Characterized in that configured to include.

A to-be-processed object installing step of installing a to-be-processed object under the dielectric attached to the electrode in an air atmosphere; A plasma generation step of generating a plasma by supplying power to the electrode; A surface etching step of etching the surface of the object by controlling the voltage and power supply time applied to the electrode; And a hydrophobic step of introducing a hydrophobic member between the other electrode spaced below the workpiece and the workpiece, and coupling the hydrophobic member to the surface of the workpiece by using a plasma. .

The hydrophobic member is characterized in that the gas or molecule containing at least one of fluorine group, methyl group and chlorine group.

In the surface etching step, a reaction gas for activating the etching of the workpiece is selectively added.

The reaction gas is characterized in that it comprises at least any one of oxygen, nitrogen, moisture, argon, helium, fluorine carbide, chlorine carbide.

The surface etching step may be a process of continuously etching the surface of the object by winding the object to be wound around the roller on another roller.

According to the present invention having such a configuration, the number of processes required to form the surface roughness of the workpiece is reduced, and there is an advantage in that the workpiece can be manufactured having a uniform and wide roughness surface.

Hereinafter, a configuration of a plasma apparatus applied to the present invention will be described in detail with reference to FIGS. 1 and 2.

Figure 1 is a schematic diagram showing the internal configuration of the vacuum plasma apparatus applied to the method of forming a super water-repellent surface through the plasma treatment according to the present invention, Figure 2 is a method of forming a super water-repellent surface through the plasma treatment according to the present invention A schematic diagram showing the internal construction of an atmospheric pressure plasma apparatus applied is shown.

As shown in these figures, in order to form the super water-repellent surface through the plasma treatment according to the present invention, as shown in Figure 1 to generate a plasma on the surface of the workpiece inside the vacuum chamber, or to the workpiece (W) This is possible by generating a plasma on the surface.

Looking at the configuration of the plasma apparatus for generating a plasma on the surface of the workpiece (W), first, a pair of vacuum chamber (C) for making the surroundings of the workpiece (W) in a vacuum atmosphere is required, The pair of vacuum chambers C are installed to communicate with each other inside.

The vacuum chamber C is provided with electrodes 10 electrically insulated from the vacuum chamber C and capable of selectively applying power.

The electrode 10 generates a plasma by applying a negative bias from the power supply device 30 provided outside the vacuum chamber C. The surface of the electrode 10 has a surface above the electrode 10. The workpiece W to be etched is positioned.

The surface of the workpiece W is continuously etched by the plasma generated inside the vacuum chamber C. For this purpose, the roller 20 is provided inside the pair of vacuum chambers C.

That is, the roller 20 is the first roller 22 located on the left side of the pair of rollers 20 is wound and supplied to the workpiece (W) to be etched on the outer circumferential surface, and in the first roller 22 It is comprised including the 2nd roller 24 by which the to-be-processed object W which was supplied and etched was wound up.

Therefore, when plasma is generated in the vacuum chamber C, the cations included in the plasma etch the surface of the workpiece W flowing from the first roller 22 to the second roller 24. Continuous etching of the workpiece W becomes possible.

In addition, various configurations may be selectively provided in the vacuum chamber C to generate plasma.

That is, a separate electrode 10 may be further provided to increase the plasma density inside the vacuum chamber C. The antenna 40 may be provided above the electrode 10 and the antenna 40 may be spaced apart from the electrode 10. It may be connected to the external power supply device 30 to generate a plasma. In addition, a microwave generally used in a microwave oven may be applied outside the vacuum chamber C to generate plasma.

The upper end of the vacuum chamber (C) is provided with a reaction gas inlet (50) that is centrally punctured and selectively shielded so that the interior of the vacuum chamber (C) communicates with the outside. The reaction gas inlet 50 is configured to increase the etching efficiency when etching the surface of the workpiece W using plasma.

That is, the reaction gas inlet 50 is a reaction gas (not shown) made of oxygen, nitrogen, water (moisture), argon, helium, hydrogen, fluorine carbide, and a mixed gas thereof flows into the vacuum chamber (C). The role is to guide.

Therefore, when the reaction gas is introduced into the vacuum chamber C through the reaction gas inlet 50, the plasma generated between the antenna 40 and the electrode 10 further performs surface etching of the workpiece W. Will be activated.

A hydrophobic member inlet 60 is formed at an upper end of the vacuum chamber C on the right side of the vacuum chamber C so that the inside of the vacuum chamber C communicates with the outside. The hydrophobic member inlet 60 guides the hydrophobic member coupled to the surface of the workpiece W to be introduced regardless of whether the ambient atmosphere is a vacuum or an atmosphere when the surface of the workpiece W is etched. The interior of the vacuum chamber (C) is in communication with the outside.

That is, when the material of the workpiece W is hydrophobic, it may have superhydrophobicity only by etching the surface by plasma (coating of the hydrophobic member, if necessary), but the material of the workpiece W is In the case of hydrophilicity, it is impossible to change the properties so as to have hydrophobicity only by forming the protrusions by plasma etching. Therefore, the hydrophobic member having hydrophobicity is attached to the surface of the workpiece W to be bonded.

The hydrophobic member is composed of a gas or a molecule including at least one of a fluorine group, a methyl group, and a chlorine group, and is introduced to the upper side of the object W through the hydrophobic member inlet 60.

FIG. 2 schematically shows a device for generating a plasma in an atmospheric atmosphere. In order to etch the surface of the workpiece W using the plasma in the atmospheric atmosphere, a pair of facing electrodes 10 are spaced apart from each other. Located above and below the furnace, one side of the electrode 10 is provided with a dielectric 70, and the lower surface of the dielectric 70 is provided with the workpiece (W).

That is, the schematic diagram shown in FIG. 2 illustrates a plasma generating apparatus which is widely known as a Dielectric Barrier Discharge (DIV) method. In order to stabilize the plasma generating apparatus, a power supply unit 30 is provided at one side of the power supply 30. ) Is generally provided with a power cut-off means (not shown) to selectively cut off power when an arc occurs, and detailed description thereof will be omitted.

However, as shown in FIG. 2, the plasma is generated in an air atmosphere, and when the surface of the workpiece W is etched, a pair of rollers 20 may also be provided to continuously work. The upper surface of the processed material W is preferably installed to be close to the dielectric 70 attached to the lower surface of the electrode 10 located above the pair of electrodes 10.

Hereinafter, a first embodiment of forming a roughness on the surface of the workpiece W using the plasma generator configured as described above will be described with reference to FIGS. 1, 3A, 4, and 5.

Figure 3a is a flow chart showing a process performed in a vacuum atmosphere in the method of forming a super water-repellent surface through the plasma treatment according to the present invention.

In the first embodiment of the present invention, the workpiece (W) is formed of a Teflon (PTFE) resin, and the workpiece (W) is installed in the vacuum chamber (C) and etched in a vacuum atmosphere.

First, the processing object installation step (S100) for mounting the processing object W on the upper surface of the electrode 10 is performed. When the workpiece W is installed on the upper surface of the electrode 10, the vacuum forming step S200 is performed by maintaining the degree of vacuum in the vacuum chamber C at 2 × 10 ⁻⁶ torr or less.

Thereafter, a plasma generation step (S300) is performed to generate a plasma by applying a 150 W power source and a negative bias of −11 V / cm 2 to the electrode 10.

At the same time as the plasma generation step (S300) is performed, the surface of the workpiece (W) is etched to go through the surface etching step (S400), the surface etching step (S400) is carried out for two hours.

At this time, in the surface etching step (S400) by winding the workpiece W wound on the first roller 22 to the second roller 24 so that the surface of the workpiece (W) can be continuously etched. do.

After the surface etching step S400, a hydrophobic member (not shown) is introduced into the vacuum chamber C through the hydrophobic member inlet 60, and the hydrophobic member is coupled to the surface of the workpiece W using a plasma. Hydrophobization step (S500) is performed.

In the first embodiment of the present invention, the hydrophobic member is CHF 3, and the degree of vacuum in the vacuum chamber C is 8 to 9 × 10 ⁻² torr while the hydrophobic member is introduced into the vacuum chamber C for 15 minutes. Was maintained. Then, 150W of power and a negative bias of −15V / cm 2 were applied to the electrode 10 to generate plasma.

As a result of measuring the contact angle by dropping water droplets on the surface of the workpiece W formed by the first embodiment described above, as shown in FIG. 4, the surface roughness of the workpiece W was 150 °. As shown in FIG. 4, it can be seen that the average roughness is 3.15 μm.

Therefore, the surface of the workpiece W according to the first embodiment has a contact angle with water of 140 ° or more, so that the surface of the workpiece W has a superplasticity.

Hereinafter, a second embodiment of forming a roughness on the surface of the workpiece W using the plasma generator configured as described above will be described with reference to FIGS. 2, 3B, 6 and 7.

In the second embodiment of the present invention, the workpiece (W) is applied to a plate formed of acrylic (PMMA) resin, the plasma etching process of the surface of the workpiece (W) was performed in the atmosphere.

Looking at the roughness forming process of the surface of the workpiece (W) according to the second embodiment, first to install the workpiece (S100) to be installed so that the workpiece (W) is located below the dielectric (70). Will be implemented.

When the workpiece W is installed under the dielectric 70, 0.8 kV to 2.5 kV of power is applied to the electrode 10 located above the pair of electrodes 10 to generate plasma for 10 minutes. (Plasma generation step: S300).

Plasma is generated below the workpiece W and at the same time, the bottom surface of the workpiece W is etched (surface etching step S400), as described above in the first embodiment. By rotating the roller 20, the object W is wound on the second roller 24, thereby enabling continuous etching.

After the hydrophobic member is introduced between the pair of electrodes 10 and the hydrophobic step of coupling the hydrophobic member to the lower surface of the workpiece (W) more precisely than the surface of the workpiece (W) by using a plasma ( S500) is optionally performed.

At this time, the hydrophobic member was applied CHF3 gas containing a fluorine group, the hydrophobization step (S500) was maintained for 5 minutes.

As a result of measuring the contact angle by dropping water droplets on the surface of the workpiece W formed by the second embodiment of the above process, as shown in FIG. It can be seen that the surface roughness is 38.6 nm when viewed as the centerline average roughness as shown in FIG. 7.

Therefore, the workpiece W having the rough surface formed through the second embodiment has a contact angle of 140 ° or more when contacted with water, thereby causing the workpiece W to exhibit superhydrophobicity.

On the other hand, in order to verify the stability of the acrylic resin made through the second embodiment of the present invention, after the UV irradiation on the surface of the workpiece (W) was measured the contact angle to water.

At this time, one lamp of 185nm wavelength and two lamps of 254nm wavelength were used simultaneously during the UV irradiation process, and the irradiation period was maintained for one week.

As a result of measuring the contact angle by dropping water droplets on the surface of the workpiece W subjected to the above UV irradiation process, as shown in FIG. 8, the contact angle was 154 °, compared with 160 ° before UV irradiation. It can be seen that only a slight change in the contact angle is shown.

The scope of the present invention is not limited to the above-exemplified embodiments, and many other modifications based on the present invention may be made by those skilled in the art within the above technical scope.

For example, in the embodiment of the present invention, although the vacuum or atmospheric pressure was performed as an environment for generating plasma, any configuration may be applied within a range in which the surface of the workpiece W is etched through the plasma.

In addition, in the embodiment of the present invention, the object to be treated is only acrylic resin and teflon resin, but any one may be applied within the range of the material which can be etched using plasma.

In the method of forming a super water-repellent surface through the plasma treatment according to the present invention as described in detail above, by generating a plasma on the surface of the workpiece under vacuum or atmospheric pressure to roughen the surface so that the contact angle with water can be 140 ° or more It was.

Therefore, since it is possible to impart hydrophobicity of the processing object by a simple process, there is an advantage that productivity is improved and manufacturing cost is significantly reduced.

Further, according to the present invention, the workpiece is configured to have hydrophobicity through the plasma regardless of the hydrophobicity or hydrophilicity of the material.

Therefore, it is possible to form a workpiece having a large area and a uniform surface roughness, and there is an advantage that can be easily applied to various fields.

Claims (6)

A to-be-processed object installing step of installing a to-be-processed object above the electrode provided in the vacuum chamber; A vacuum forming step of forming an inside of the vacuum chamber in a vacuum atmosphere; A plasma generation step of generating a plasma by supplying power to the electrode; A surface etching step of etching the surface of the object by controlling the voltage and power supply time applied to the electrode; A hydrophobic step of introducing a hydrophobic member into the vacuum chamber and coupling the hydrophobic member to the surface of the object by using a plasma; A to-be-processed object installing step of installing a to-be-processed object under the dielectric attached to the electrode in an air atmosphere; A plasma generation step of generating a plasma by supplying power to the electrode; A surface etching step of etching the surface of the object by controlling the voltage and power supply time applied to the electrode; And a hydrophobic step of introducing a hydrophobic member between the other electrode spaced below the workpiece and the workpiece, and coupling the hydrophobic member to the surface of the workpiece using a plasma. Super water-repellent surface formation method through plasma treatment The hydrophobic member according to claim 1 or 2, Method for forming a super water-repellent surface through a plasma treatment, characterized in that the gas or molecule containing at least one of fluorine group, methyl group and chlorine group. The method of claim 1 or 2, wherein in the surface etching step, A method of forming a super water-repellent surface through plasma treatment, characterized in that a reaction gas for activating the etching of the workpiece is selectively added. The method of claim 4, wherein the reaction gas, A method of forming a super water-repellent surface by plasma treatment, comprising at least one of oxygen, nitrogen, moisture, argon, helium, fluorine carbide, and chlorine carbide. According to claim 1 or 2, wherein the surface etching step, A method of forming a super water-repellent surface by plasma treatment, characterized in that the process of continuously etching the surface of the workpiece by winding the workpiece to be wound on another roller.

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