KR20230174420A - Development of Super Water-repellent (Super Oil-repellent) Aluminum 3000 Series Alloy Surface using Nanostructures - Google Patents

Abstract

The present invention relates to the development of a super water-repellent (super oil-repellent) aluminum 3000 series alloy surface using nanostructures. The method for producing an oil-repellent and water-repellent film on the 3000 series aluminum alloy surface according to the present invention is a cross-linking method represented by Chemical Formula 1. By using PDMS derivatives and organic solvents in a specific mixing ratio, water and oil repellency can be imparted, the manufacturing cost is low, and the coating film thickness can be adjusted from several to tens of nm, so it can also be applied to the coating of microstructured oxide films. , It can be useful for oil vapor recovery devices/equipment, pipes, hoods, hood parts, nozzles, pipes, etc. that require water and oil repellency.

Description

Development of Super Water-repellent (Super Oil-repellent) Aluminum 3000 Series Alloy Surface using Nanostructures}

The present invention relates to the development of a super water-repellent (super oil-repellent) aluminum 3,000 series alloy surface using nanostructures.

In general, water repellency and oil repellency refer to properties that make it difficult to get wet with water and oil, respectively. Super water repellency/super oil repellency refers to a product in the relevant field where the contact angle of water in contact with the surface of a solid is 150° or more and the contact angle of oil is 150° or more. It is generally defined as a case.

Recently, superhydrophobic surfaces with water contact angles greater than 150° have attracted considerable attention due to their importance in both basic research and practical applications. Superhydrophobicity and superoleophobicity refer to physical properties that make the surface of an object extremely difficult to get wet with water and oil, respectively. For example, plant leaves, insect wings, or bird wings have properties that allow any external contaminants to be removed without special removal work or to prevent contamination in the first place. This is because plant leaves, insect wings, and bird wings have superhydrophobic properties.

Wettability is a key surface property of solid materials, and it is largely governed by both chemical composition and geometric micro/nanostructure. Wettable surfaces have attracted much attention due to their potential applications in various fields such as oil-water separation, anti-reflection, anti-bioadhesion, anti-adhesion, anti-fouling, self-cleaning, and fluid turbulence suppression.

Meanwhile, there have been several reports on the production of superhydrophobic aluminum, but superhydrophobicity/superoleophobicity on metal substrates has not received relatively much attention.

As air pollution due to recent environmental pollution has become more serious and the occurrence of yellow dust and fine dust has increased, it is often necessary to operate ventilation devices to purify indoor air rather than opening windows to ventilate. In addition, household dust, food odor, cigarette odor, various harmful odors generated during work, and harmful substances such as carbon monoxide generated in residential facilities, business facilities, and commercial facilities such as homes, workshops, industrial sites, restaurants, offices, restrooms and bathrooms, etc. Ventilation devices are constantly operated to remove air, fine dust, and oil vapor.

These ventilation devices are generally systemized and installed in a specific location and implemented by complex facilities such as a ventilation system that automatically operates depending on the level of indoor pollution, or are installed on a wall adjacent to the outside and are window fans that simply circulate the air between the inside and outside. It is implemented by .

However, when these ventilators are used for a certain period of time, there is a problem that dust inevitably accumulates inside and outside the ventilator, which is unhygienic and requires the cumbersome task of removing the ventilator and cleaning it to remove the dust.

In particular, ventilators installed in restaurants or places where oil vapor is generated do not have any filtering device to primarily absorb oil or fine dust, so when used for a long period of time, oil and fine dust combine and flow downward, which can lead to sanitary problems. Not only can this cause serious concern, but it can also expose one to the risk of fire.

Public Patent Publication No. 10-2014-0101193

The purpose of the present invention is to provide a method for producing an oil-repellent and water-repellent film on 3000 series aluminum alloy.

Another object of the present invention is to provide a 3000 series aluminum alloy with an oil-repellent and water-repellent film produced by the above manufacturing method.

Another object of the present invention is to provide a method of manufacturing a pillar-on-pore type anodized film on the surface of a 3000 series aluminum alloy.

Another object of the present invention is to provide a 3000 series aluminum alloy with a pillar-on-pore type anodized film produced by the above manufacturing method.

In order to achieve the above purpose,

The present invention involves primary anodizing a 3000 series aluminum alloy at 30-50V for 5-15 hours, followed by etching to remove the primary anodization film (step 1). ;

secondary anodizing at 35-45 V for 1-10 minutes (step 2);

Pore widening process by immersing in 0.05-1.0M phosphoric acid (H ₃ PO ₄ ) solution for 10-60 minutes (step 3);

tertiary anodizing at 35-45 V for 1-10 minutes (step 4); and

Comprising: coating with a coating composition containing a cross-linked PDMS (polydimethylsiloxane) derivative represented by the following formula (1) and an organic solvent (step 5);

Provides a method for manufacturing oil-repellent and water-repellent films on 3000 series aluminum alloy.

[Formula 1]

(In Formula 1, x and y are each integers of 1-30.)

In the manufacturing method according to the present invention, step 1 is a pre-patterning process that involves anodizing the 3000 series aluminum alloy and then etching to remove the anodized film, thereby forming a microstructure pattern on the surface of the 3000 series aluminum alloy. This is the remaining process. An anodized film formed by post-process anodization treatment can be uniformly formed along the microstructure pattern of the surface of the metal substrate formed by the pre-patterning process.

In the manufacturing method according to the present invention, steps 2 to 4 include forming an anodized film with a pillar-on-pore (POP) structure on the surface of the 3000 series aluminum alloy through anodizing and pore expansion treatment. This is the manufacturing stage for forming. Here, the anodized film exhibits hydrophilicity, and the anodized film of the POP structure according to the present invention exhibits superhydrophilicity. Here, the coating composition according to step 5 is intended to provide oil and water repellency. By coating the micronano surface of the POP structure thinly to a monomolecular layer thickness, the micronano surface structure of the anodized film is maintained to provide oil and water repellency. The technical feature is to maximize the effect.

The 3000 series aluminum alloy may include Al 3003, Al 3004, Al 3005, Al 3015, Al 3103, Al 3104, and Al 3105.

The anodized film exhibits hydrophilicity, and in one embodiment of the present invention, the anode has a pillar-on-pore microstructure in which pillars are formed on the pore structure according to steps 1 to 4. The oxide film can exhibit super-hydrophilicity with a contact angle of 10° or less.

Preferably,

Secondary anodizing of the pre-patterned 3000 series aluminum alloy at 38-42V for 3-7 minutes (step 2);

Pore widening process by immersing in 0.05-0.15M phosphoric acid (H ₃ PO ₄ ) solution for 30-45 minutes (step 3); and

It may include tertiary anodizing treatment at 38-42V for 3-7 minutes (step 4).

More preferably,

secondary anodizing at 39-41 V for 3-5 minutes (step 2);

Pore widening process by immersing in 0.06-0.14M phosphoric acid (H ₃ PO ₄ ) solution for 33-42 minutes (step 3); and

It may include tertiary anodizing treatment at 39-41V for 3-5 minutes (step 4).

Especially preferably,

secondary anodizing at 39.5-40.5 V for 3.8-4.2 minutes (step 2);

Pore widening process by immersing in 0.095-0.105M phosphoric acid (H ₃ PO ₄ ) solution for 34-41 minutes (step 3); and

It may include a third anodizing process (step 4) at 39.5-40.5V for 3.8-4.2 minutes.

If the processing conditions of steps 2 to 4 described above are exceeded, problems may arise in which a uniform anodized film is not formed or superhydrophilicity cannot be achieved.

In the anodizing process, an anode is placed in an oxidation treatment tank containing an electrolyte at -5 to 30°C using the 3000 series aluminum alloy to be anodized as a working electrode, and then a platinum (Pt) or carbon electrode is used as the counter electrode. This may be achieved by applying a cathode and oxidizing it. The distance between the working electrode and the counter electrode may be 1-15 cm, preferably 3-12 cm, more preferably 4-10 cm, even more preferably 4.5-8 cm, especially preferably 4.75-5.25 cm. It can be cm.

Electrolytes for the first and second anodic oxidation treatments include sulfuric acid (H ₂ SO ₄ ), phosphoric acid (H ₃ PO ₄ ), oxalic acid (C ₂ H2O ₄ ), and chromic acid, respectively. Chromic acid, hydrofluoric acid, dipotassium phosphate (K ₂ HPO ₄ ), etc. can be used alone or in a mixture of two or more.

Preferably, the electrolyte solution may use 0.1-0.5M oxalic acid at -5 to 25°C, more preferably 0.27-0.33M oxalic acid at 15 to 25°C, and particularly preferably 19 to 21°C. 0.285-0.315M oxalic acid can be used.

In the coating composition used in step 5, the organic solvent may be Pentane, Hexane, Heptane, Octane, etc., alone or in a mixture of two or more. In the present invention, hexane is used as an example. (Hexane) was used.

Preferably,

The coating composition used in step 5 is,

Based on 10 parts by weight of organic solvent,

It may contain 0.01-10 parts by weight of a cross-linked polydimethylsiloxane (PDMS) derivative represented by Formula 1.

More preferably,

The coating composition used in step 5 is,

Based on 10 parts by weight of organic solvent,

It may contain 0.04-5 parts by weight of a cross-linked polydimethylsiloxane (PDMS) derivative represented by Formula 1.

Even more preferably,

The coating composition used in step 5 is,

Based on 10 parts by weight of organic solvent,

It may contain 0.04-2 parts by weight of a cross-linked polydimethylsiloxane (PDMS) derivative represented by Formula 1.

Especially preferably,

The coating composition used in step 5 is,

Based on 10 parts by weight of organic solvent,

It may contain 0.04-1 part by weight of a cross-linked polydimethylsiloxane (PDMS) derivative represented by Formula 1.

Most preferably,

The coating composition used in step 5 is,

Based on 10 parts by weight of organic solvent,

It may contain 0.05-0.17 parts by weight of a cross-linked polydimethylsiloxane (PDMS) derivative represented by Formula 1.

If the content of the cross-linked PDMS derivative represented by Formula 1 is outside the above range, oil and water repellency may be reduced, or there may be a problem of insufficient uniformity of the coating.

The coating composition according to the present invention is characterized in that it does not contain PDMS (Polydimethylsiloxane) derivative represented by the following formula (2).

[Formula 2]

(In Formula 2, m is an integer of 1-100, preferably an integer of 1-80, and more preferably an integer of 1-60.)

The coating composition may be used by methods such as drop coating, dip coating, and spin coating, but is not limited thereto.

In addition, the present invention provides a 3000 series aluminum alloy with an oil-repellent and water-repellent film produced by the above manufacturing method.

Furthermore, the present invention is a pre-patterning step (step) of first anodizing a 3000 series aluminum alloy at 30-50V for 5-15 hours and then etching to remove the primary anodization film. One);

secondary anodizing at 35-45 V for 1-10 minutes (step 2);

Pore widening process by immersing in 0.05-1.0M phosphoric acid (H ₃ PO ₄ ) solution for 10-60 minutes (step 3); and

Comprising a tertiary anodizing step (step 4) at 35-45V for 1-10 minutes,

A method of manufacturing a pillar-on-pore type anodized film on the surface of a 3000 series aluminum alloy is provided.

The pillar-on-pore type anodized film is characterized in that pillars are formed on the pore structure, and the anodized film is characterized in that it is superhydrophilic.

In addition, the present invention provides a 3000 series aluminum alloy with a pillar-on-pore type anodized film produced by the above manufacturing method.

The method for producing a superhydrophilic anodized film on a 3000 series aluminum alloy according to the present invention can produce a uniform anodized film, depending on the coating composition using a cross-linked PDMS derivative represented by Chemical Formula 1 and an organic solvent at a specific mixing ratio. Superhydrophobicity and superoleophobicity can be imparted to the anodized film, the coating composition is inexpensive to manufacture, and the coating film thickness can be adjusted to several to tens of nm, so it can also be applied to the coating of microstructured oxide films.

Figure 1 is a field emission scanning electron microscope (FE-SEM) showing the top view, cross view, and tilted view of a specimen processed from Examples 1-1 to 1-2 through tertiary anodization (step 4). It is one image.

Hereinafter, the present invention will be described in more detail through the following examples. However, the following examples are merely illustrative of the present invention, and the content of the present invention is not limited by the following examples.

<Manufacturing example> Manufacture of an anodized film with a Pillar-On-Pore (POP) structure through anodizing aluminum 3003 alloy

In order to find out the anodizing treatment conditions under which a POP-structured anodized film is formed on the surface of aluminum 3003 alloy, the following was carried out.

To manufacture an aluminum alloy anodized film, pre-patterning, pore widening (PW), and voltage modulation were performed using aluminum 3003 alloy.

The component information of the aluminum 3003 alloy (Al 3003, size 20 × 30 mm, manufacturer: Alcoa INC, USA) is as follows.

Preparation stage: Electrochemical polishing process

To remove impurities on the surface of the aluminum 3003 alloy, it was cleaned by sonicating in acetone at 20°C for 10 minutes and then in ethanol for 10 minutes.

Next, in order to obtain surface roughness, the ultrasonic cleaned aluminum 3003 alloy was placed in a mixed solution of ethanol and perchloric acid (Junsei, HClO ₄ :C ₂ H ₅ OH= 4:1 (v/v)) at room temperature (20°C). A voltage of 20V was applied and electrochemical polishing was performed for 1 minute. It was confirmed that the aluminum alloy surface after electrolytic polishing was well reflected and had a flat surface.

Step 1: Pre-patterning process through primary anodization and chemical etching

The electropolished aluminum 3003 alloy (thickness 1 mm, size 20 Secondary anodization was performed. The first anodization was performed using 0.3M oxalic acid as an electrolyte, and using a double beaker while keeping the electrolyte temperature constant at 0°C. In order to suppress interference with stable oxide growth due to local temperature rise, the mixture was stirred at a constant speed, and a voltage of 40V was applied using a constant voltage method to perform the first anodization process for 6 hours to grow an alumina layer.

The alumina layer grown through the first anodization treatment was etched by immersing it in a mixed solution of chromic acid (1.8 wt%) and phosphoric acid (6 wt%) at 65°C for 10 hours to remove the grown alumina layer. A pre-patterning process was performed.

Step 2: Secondary anodization

The pre-patterned aluminum 3003 alloy (1 mm thick, 20 Secondary anodization was performed. The secondary anodic oxidation was performed using 0.3M oxalic acid as an electrolyte, and using a double beaker while maintaining the electrolyte temperature constant at 20°C. In order to suppress interference with stable oxide growth due to local temperature rise, the mixture was stirred at a constant speed, and a secondary anodization process was performed by applying a voltage of 40V for 1-10 minutes using a constant voltage method to grow an alumina layer.

Step 3: Pore widening (PW)

The alumina layer grown through secondary anodization was subjected to a pore widening (PW) process by immersing it in a 0.1M phosphoric acid solution at 30°C for 10 to 60 minutes before performing third anodization.

Step 4: Tertiary anodization

The third anodization process was performed in the same manner as the second anodization, but the voltage application time was fixed to 4 minutes to further grow the alumina layer.

The secondary anodization (step 2), pore expansion (step 3), and tertiary anodization (step 4) processes were performed under the conditions shown in Table 1 below to produce a microstructured anodized film on the surface of aluminum 3003 alloy. did.

Secondary anodization
(Step 2) pore expansion
(Step 3) 3rd anodization
(Step 4) Voltage (V) Time (min) Time (min) Voltage (V) Time (min) Example 1-1 40 4 35 40 4 Example 1-2 40

<Experimental Example 1> Microstructure analysis of anodized film

The surface (top view), cross section (cross view), and tilted view of the specimens treated from Examples 1-1 to 1-2 in Table 1 up to the tertiary anodization (step 4) were Observations were made using a field emission scanning electron microscope (FE-SEM) system (AURIGA® small dual-bean FIB-SEM, Zeiss).

Figure 1 is a field emission scanning electron microscope (FE-SEM) showing the top view, cross view, and tilted view of a specimen processed from Examples 1-1 to 1-2 through tertiary anodization (step 4). It is one image.

As shown in Figure 1, the bottom part that appears smooth in the cross-view image of the specimen treated with pore expansion for 35 min is aluminum 3003 alloy, and the thickness of the pillar layer in the form of pores below is a film resulting from tertiary anodization. It has a porous pillar shape, and the upper part of it has a pillar shape due to a film resulting from secondary anodization and pore expansion treatment. It appears that the POP microstructure appears well in specimens treated with pore expansion of 35-40 min (especially 40 min).

From the results of Experimental Example 1, it is determined that it is preferable to perform the second anodization at an applied voltage of 40V for 4 min, pore expansion for 35-40 min, and the third anodization at an applied voltage of 40V for 4 min.

<Experimental Example 2> Evaluation of coating composition for imparting superhydrophobic and superoleophobic functionality

Coating compositions to be used for imparting superhydrophobic and superoleophobic functionality to the specimens of Examples 1-1 to 1-2 were evaluated.

Specifically, aluminum 3003 alloy was prepared as a metal substrate by subjecting it to the electrolytic polishing process described in the examples. That is, anodizing treatment was not performed.

As a coating agent on electropolished aluminum 3003 alloy, SYLGARD 184 Silicon Elastomer Curing Agent, a cross-linked PDMS derivative represented by Chemical Formula 1 (manufacturer: Dow chemical company), and SYLGARD 184 Silicon Elastomer Base, a PDMS derivative represented by Chemical Formula 2 (manufacturer: Dow chemical company) and/or hexane were dropped at 60 μL per 2.5 cm x 3 cm of substrate area, and then coated by spin coating. Spin coating conditions were performed at 1000 rpm for 30 seconds. Additionally, drop coating was performed using another coating method. In the case of drop coating, an appropriate amount of coating agent was dropped and the substrate was coated by tilting it left and right several times.

Preparation Examples 2-1 to 2-4 used a mixture of hexane, base material (Formula 2), and curing agent (Formula 1) as a coating agent,

Preparation Examples 2-5 to 2-10 used a mixture of hexane and a curing agent (Formula 1) as a coating agent.

Next, the coated substrate was heat treated in an oven at 300°C for 30 minutes to complete curing.

For reference, the coating compositions of Preparation Examples 2-1 to 2-10 below are the compositions used in the inventor's earlier application (Application No. 10-2021-0085454).

Manufacturing example Coating composition (weight ratio) coating
method coating liquid
usage
(μL/7.5cm ² ) hexane coating agent
(SYLGARD 184) Base
(subject) Curing agent
(hardener) 2-1 10 One 0.1 drop 65 2-2 10 One 0.1 spin 65 2-3 10 2 0.2 drop 65 2-4 10 2 0.2 spin 65 2-5 10 0 One drop 65 2-6 10 0 One spin 65 2-7 10 0 One spin 65 2-8 10 0 One drop 85 2-9 10 0 0.5 drop 85 2-10 10 0 0.1 drop 85

[Formula 1: Curing agent]

In Formula 1, x and y are each integers of 1-30.

[Formula 2: Base]

In Formula 2, m is an integer of 1-100.

For the specimens of Preparation Examples 2-1 to 2-10, water (purified water) and oil (cooking oil) were respectively dropped to evaluate the contact angle and contact hysteresis angle, and the results are shown in Table 3 below.

Here, 'contact angle hysteresis' refers to placing a sample on the stage of a device whose tilt is finely adjustable, dropping water or oil on the sample, then gradually adding a tilt to the stage, and allowing the water or oil to flow. The angle of inclination at which it begins to fall is measured. In other words, the lower the contact hysteresis angle, the better the water/oil repellency. For example, if the contact hysteresis angle is 1°, water or oil will flow out even if the sample is tilted just 1°, and if the contact hysteresis angle is 90°, water or oil will not flow out even if the sample is tilted at 90°.

Table 3 below shows the results of evaluating water and oil repellency after coating the coating solution according to Preparation Examples 2-1 to 2-10 on an unanodized sample of an aluminum 3003 alloy substrate without a microstructure oxide film formed on the surface. .

Non -anodized substrate water oil Contact angle (0 seconds) Contact hysteresis angle Contact angle (60 seconds) Contact hysteresis angle Manufacturing Example 2-1 107.59±1.31° 29.11±0.44° 60.56±0.43° 25.74±0.41° Manufacturing Example 2-2 104.57±0.35° 25.65±0.58° 61.05±0.67° 26.95±0.64° Manufacturing Example 2-3 99.57±0.22° 27.43±0.75° 57.05±1.05° 27.56±0.37° Manufacturing Example 2-4 100.28±1.24° 27.91±0.94° 54.87±1.44° 27.79±0.09° Manufacturing Example 2-5 102.66±0.80° 22.20±0.58° 60.79±1.38° 22.12±0.37° Manufacturing Example 2-6 100.87±3.00° 28.32±0.85° 58.44±6.00° 28.52±2.90° Manufacturing Example 2-7 103.96±2.83° 24.19±0.24° 59.62±1.43° 24.86±1.40° Manufacturing Example 2-8 114.13±2.53° 20.07±0.41° 58.84±3.10° 20.60±0.20° Manufacturing Example 2-9 113.22±1.47° 19.94±2.20° 54.55±8.12° 13.75±1.02° Manufacturing Example 2-10 114.63±0.18° 13.66±0.42° 55.01±2.48° 10.65±0.92° Uncoated 77.72±4.64° 41.26±4.31° 31.67±6.02° 33.57±0.68°

As shown in Table 3, Preparation Example 2-10 had the lowest contact hysteresis angle, confirming that it had excellent water/oil repellency. Based on the results, the coating composition according to Preparation Example 2-10 was used in Experimental Example 3, which will be described later.

<Experimental Example 3> Evaluation of water and oil repellency of samples coated with the coating composition of Preparation Example 2-10 on the samples of Examples 1-1 to 1-2

The coating composition of Preparation Example 2-10 was coated using the aluminum 3003 alloy on which the microstructured anodized film obtained in Examples 1-1 and 1-2 was formed as a base. The detailed coating process was carried out in the same manner as in Experimental Example 2 above.

For the coated specimens (Examples 2-1 to 2-2), water (purified water) and oil (cooking oil) were dropped respectively to evaluate the contact angle and contact hysteresis angle, and the results are shown in Table 4 below. It was.

Here, when a metal substrate is anodized to form a POP-type microstructure on the surface, a superhydrophilic oxide film is formed. This is an effect caused by the oxygen atoms and microstructure contained in the oxide film, and the microstructure oxide film has a monomolecular film level. If the microstructure is maintained by applying a thin hydrophobic coating, superhydrophobicity can be realized.

water (°) Oil (°) Contact angle (0 seconds) contact hysteresis angle Contact angle (0 seconds) contact hysteresis angle Example 2-1 165.88±18.61 9.78±0.47 73.46±1.11 15.27±1.92 Example 2-2 173.79±12.71 3.19±0.64 75.23±1.04 13.31±1.04

As shown in Table 4, it was confirmed that the contact hysteresis angles of Examples 2-1 and 2-2 exhibited initial water-repellent and initial oil-repellent properties, and in particular, it was confirmed that Example 2-2 showed excellent effects. .

<Experimental Example 4> Derivation of the optimal mixing ratio of the cross-linked PDMS derivative of Formula 1 and hexane suitable for coating on a substrate with a microstructured oxide film

Through the results of Experimental Examples 2 and 3, it was found that the coating composition sample of Preparation Example 2-10 had excellent coating properties, significantly excellent water repellency and oil repellency, and formed a coating film thickness thin enough to maintain the microstructure. I was able to confirm.

Therefore, in this Experimental Example 4, a contact hysteresis angle experiment was conducted in the same manner as in Experimental Example 3 to derive the optimal mixing ratio of the cross-linked PDMS derivative of Formula 1 and hexane suitable for coating on a substrate with a microstructured oxide film, and the results were It is shown in Table 5.

In Table 5 below, the curing agent and hexane of the coating agent are measured and expressed by weight ratio, and the base material used was aluminum 3003 alloy with a POP-type microstructure oxide film obtained in Example 1-2, and was subjected to plasma treatment in the same manner as Preparation Example 2-10. Samples were prepared by drop coating without treatment.

Example Coating mixing weight ratio Contact hysteresis angle (°) hexane hardener
(Formula 1) water oil 3-1 10 0.01 17.92 ± 0.12 19.3 ± 0.45 3-2 10 0.03 17.71 ± 0.79 18.4 ± 0.41 3-3 10 0.05 3.27 ± 0.46 13.44 ± 0.36 3-4 10 0.07 3.25 ± 0.75 13.38 ± 0.54 3-5 10 0.1 3.19 ± 0.64 13.31 ± 1.04 3-6 10 0.13 3.36 ± 0.57 13.44 ± 0.28 3-7 10 0.15 3.41 ± 0.17 14.31 ± 0.41 3-8 10 0.17 3.55 ± 0.54 14.62 ± 0.52 3-9 10 0.20 15.77 ± 0.41 20.7 ± 0.86

As shown in Table 5, in Examples 3-3 to 3-8, a coating film thickness thin enough to maintain the microstructure was formed, and the coating film was formed uniformly over the entire substrate, showing significantly excellent water and oil repellency. was able to confirm. On the other hand, in the case of Examples 3-1 to 3-2, the curing agent content was too low, so it is expected that a coating film was not formed on part of the substrate, and in the case of Example 3-9, the curing agent content was too high, and it was too thick to maintain the microstructure. A coating film is expected to be formed.

<Experimental Example 5> Contact angle evaluation of Examples 1-1 to 1-2

The contact angles for water (purified water) and oil (cooking oil) were measured for the specimens of Examples 1-1 to 1-2 without coating, and the results are shown in Table 6 below.

Contact angle (°) Pore expansion time (min) water oil Example 1-1 35 8.9 ± 3.45 None Example 1-2 40 None None

* None: This means that measurement is impossible because the contact angle is close to 0.

As shown in Table 2, it was confirmed that both Examples 1-1 and 1-2 had a contact angle to water and oil of 10° or less, indicating superhydrophilicity.

So far, the present invention has been examined focusing on its preferred embodiments. A person skilled in the art to which the present invention pertains will understand that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an explanatory perspective rather than a limited perspective. The scope of the present invention is set forth in particular in the claims rather than the foregoing description, and all differences within the equivalent scope should be construed as being included in the present invention.

Claims (18)

A pre-patterning step (step 1) in which the 3000 series aluminum alloy is subjected to primary anodization at 30-50V for 5-15 hours and then etched to remove the primary anodization film;
secondary anodizing at 35-45 V for 1-10 minutes (step 2);
Pore widening process by immersing in 0.05-1.0M phosphoric acid (H ₃ PO ₄ ) solution for 10-60 minutes (step 3);
tertiary anodizing at 35-45 V for 1-10 minutes (step 4); and
Comprising: coating with a coating composition containing a cross-linked polydimethylsiloxane (PDMS) derivative represented by the following formula (1) and an organic solvent (step 5);
Method for manufacturing oil-repellent and water-repellent films on 3000 series aluminum alloy.
[Formula 1]

(In Formula 1, x and y are each integers of 1-30.)
According to paragraph 1,
A manufacturing method, characterized in that the 3000 series aluminum alloy is at least one selected from the group consisting of Al 3003, Al 3004, Al 3005, Al 3015, Al 3103, Al 3104, and Al 3105.
According to paragraph 1,
A manufacturing method characterized in that the anodized film formed on the surface of the 3000 series aluminum alloy through steps 1 to 4 is in the form of a pillar-on-pore with pillars formed on the pore structure.
According to paragraph 1,
secondary anodizing at 38-42V for 3-7 minutes (step 2);
Pore widening process by immersing in 0.05-0.15M phosphoric acid (H ₃ PO ₄ ) solution for 30-45 minutes (step 3); and
A manufacturing method comprising the step of performing tertiary anodization at 38-42V for 3-7 minutes (step 4).
According to paragraph 4,
secondary anodizing at 39-41 V for 3-5 minutes (step 2);
Pore widening process by immersing in 0.06-0.14M phosphoric acid (H ₃ PO ₄ ) solution for 33-42 minutes (step 3); and
A manufacturing method comprising the step of tertiary anodization at 39-41V for 3-5 minutes (step 4).
According to clause 5,
secondary anodizing at 39.5-40.5 V for 3.8-4.2 minutes (step 2);
Pore widening process by immersing in 0.095-0.105M phosphoric acid (H ₃ PO ₄ ) solution for 34-41 minutes (step 3); and
A manufacturing method comprising the step of tertiary anodization at 39.5-40.5V for 3.8-4.2 minutes (step 4).
According to paragraph 1,
A manufacturing method characterized in that the organic solvent in Step 5 is one of Pentane, Hexane, Heptane, and Octane.
According to paragraph 1,
The coating composition used in step 5 is,
Based on 10 parts by weight of organic solvent,
A manufacturing method comprising 0.01-10 parts by weight of a cross-linked polydimethylsiloxane (PDMS) derivative represented by Formula 1.
According to clause 8,
The coating composition used in step 5 is,
Based on 10 parts by weight of organic solvent,
A manufacturing method comprising 0.04-5 parts by weight of a cross-linked PDMS (polydimethylsiloxane) derivative represented by Formula 1.
According to clause 9,
The coating composition used in step 5 is,
Based on 10 parts by weight of organic solvent,
A manufacturing method comprising 0.04-2 parts by weight of a cross-linked polydimethylsiloxane (PDMS) derivative represented by Formula 1.
According to clause 10,
The coating composition used in step 5 is,
Based on 10 parts by weight of organic solvent,
A manufacturing method comprising 0.04-1 part by weight of a cross-linked polydimethylsiloxane (PDMS) derivative represented by Formula 1.
According to clause 11,
The coating composition used in step 5 is,
Based on 10 parts by weight of organic solvent,
A manufacturing method comprising 0.05-0.17 parts by weight of a cross-linked polydimethylsiloxane (PDMS) derivative represented by Formula 1.
According to paragraph 1,
A manufacturing method characterized in that the coating composition used in step 5 does not include PDMS (Polydimethylsiloxane) derivative represented by the following formula (2).
[Formula 2]

(In Formula 2 above, m is an integer of 1-100.)
A 3000 series aluminum alloy with an oil-repellent and water-repellent film manufactured by the manufacturing method of claim 1.
A pre-patterning step (step 1) in which the 3000 series aluminum alloy is subjected to primary anodization at 30-50V for 5-15 hours and then etched to remove the primary anodization film;
secondary anodizing at 35-45 V for 1-10 minutes (step 2);
Pore widening process by immersing in 0.05-1.0M phosphoric acid (H ₃ PO ₄ ) solution for 10-60 minutes (step 3); and
Comprising: tertiary anodizing treatment at 35-45V for 1-10 minutes (step 4);
Method of manufacturing a pillar-on-pore type anodized film on the surface of 3000 series aluminum alloy.
According to clause 15,
A manufacturing method wherein the pillar-on-pore type anodized film has pillars formed on the pore structure.
According to clause 15,
A manufacturing method wherein the anodized film is superhydrophilic.
A 3000 series aluminum alloy with a pillar-on-pore type anodized film manufactured by the manufacturing method of claim 15.