KR20150085300A - Powder coating composition for top coating of aluminium sputtering wheel - Google Patents

Abstract

The present invention relates to a powder paint composition for top-coating aluminium sputtering wheels, which has high transparency, represents vivid colors of sputtering and maintains transparency even though a cleansing detergent is used wherein the powder paint composition for top-coating aluminium sputtering wheels is made by mixing 72-80 parts by weight of at least one acrylic resin, 16-24 parts by weight of an acrylic curing agent and 2-4 parts by weight of an additive.

Description

[0001] Powder coating composition for aluminum sputtering wheel [0002]

The present invention relates to a powder coating composition for an aluminum sputtering wheel having high transparency, capable of expressing sputtering hues well, and free from deterioration of transparency due to a cleaning detergent.

Generally, a wheel supporting an automobile tire is divided into an iron wheel bent by a steel plate, that is, an aluminum wheel made of a cast iron wheel and aluminum. Currently, it is common to use aluminum wheels on most vehicles.

Aluminum is not only beautiful, but also lightweight, easy to handle, and has high thermal conductivity, so it can quickly absorb and release the heat generated by the tire due to friction with the ground during traveling, thus preventing overheating of the tire.

In addition, since the aluminum wheel has a strong strength, it is not easily crushed or broken like a cast iron wheel when the tire is broken in the middle of running.

The functionally excellent aluminum wheel was used for the top coating work to protect the sputtering film after forming the sputtering film of metal such as aluminum, nickel, chromium and the like. However, since the transparency of the top coating was low, the sputtering color could not be expressed properly, Deterioration of transparency due to detergent occurred.

Korean Registered Patent No. 10-0971290 (registered on July 13, 2010)

Disclosure of Invention Technical Problem [8] The present invention has been made in order to solve the above problems, and it is an object of the present invention to provide a sputtering membrane excellent in transparency and excellent in hue of a sputtering film, It is an object of the present invention to provide a thermosetting acrylic powder coating which is applicable to a sputtering coating giving a plating texture.

In order to achieve the above object, the powder coating composition for aluminum sputter wheel top according to the present invention comprises 72 to 80 parts by weight of at least one acrylic resin, 16 to 24 parts by weight of an acrylic hardener, and 2 to 4 parts by weight of an additive.

In this case, the acrylic resin is an acrylic resin having an epoxide ring end group.

The acrylic resin is characterized by having an epoxy equivalent of 300 to 700 and at least one acrylic resin having the same or different hardness classifications.

Also, the acrylic hardener is Dodecanedioic acid (DDDA).

The acrylic curing agent has an equivalent weight of 450 to 530.

The additive is characterized by containing at least one of a dispersant, a pinhole inhibitor and a light stabilizer.

The powder coating composition for an aluminum sputtering wheel according to the present invention is formed by sputtering a metal such as aluminum, nickel or chromium on an aluminum wheel, painting and heat-treating the acrylic powder transparent paint according to the present invention on the surface thereof, And excellent corrosion resistance and water resistance can be obtained.

In addition, it is possible to improve the quality of the aluminum wheel with a beauty that is almost equal to that of the chrome-plated aluminum wheel while minimizing environmental damage.

Also, it is excellent in corrosion resistance, acid resistance and abrasion resistance against cleaning detergent or brine without deteriorating the luster and hue of the sputtered surface, and is advantageous in terms of manufacturing cost as well as environment friendliness compared to a chrome wheel.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the powder coating composition for aluminum sputter wheel top according to the present invention will be described in detail.

Generally, in the wheel manufacturing process, an aluminum ingot is cast by a press to form a wheel, and then the following post-processing is performed.

(1) Material preparation step

This step is a step of removing foreign substances on the aluminum wheel surface by shooting a shot ball on the surface of the aluminum wheel while the aluminum ingot is processed into a wheel shape and improving the adhesion of the paint. Is shot with a shot ball and removed, and in addition, it is a step for enhancing the adhesion of the coating to be described below.

(2) polishing step

In the polishing step, in order to even out the surface of the product after plating, the step of abrading the rough surface of the aluminum wheel by hitting the shot ball with the shot ball in the above step to remove the roughness of the surface, And grinding.

(3) Pre-treatment step

This step is made up of various processes. Even if foreign substances adhering to the surface of the aluminum wheel are removed as described above, the removal rate is insufficient and therefore it is necessary to completely remove the foreign substances. The reason for carrying out such a step is to improve the adhesion of the paint in the step of undercoat powder coating and top coat described below, to smooth and smooth the surface of the aluminum wheel and to improve the gloss.

The processes in this step are largely divided into a bale process, a preliminary degreasing process, a main degreasing process, a first to second water washing process, a neutralization process, a third to fourth water washing process, a coating process, a fifth to sixth water washing process, Process, and a water-drying process.

The first boiling process is a process of removing contaminants by spraying hot water of 55 ± 10 ℃ at injection pressure of 1.0 ~ 2.0kgf / ㎠ to remove contaminants such as foreign matter and oil on the surface of aluminum wheel.

Next, the aluminum wheel that has undergone the boiling process is subjected to a preliminary degreasing process. The preliminary degreasing process is performed in order to facilitate the main degreasing process as described below since the surface of the aluminum wheel surface subjected to the bushing process is activated and a surfactant component having a small concentration is adhered thereto. And spraying hot water of 占 10 占 폚 at an injection pressure of 1.0 to 2.0 kgf / cm2 to remove contaminants again.

Next, the aluminum wheel subjected to the preliminary degreasing process is subjected to this degreasing process. This degreasing process is a process of completely removing contaminants on the aluminum wheel surface by spraying a liquid detergent at 55 ± 10 ° C diluted with surfactant in hot water at a spray pressure of 1.0 to 2.0 kgf / . As described above, oil and other foreign substances on the aluminum wheel surface are completely removed when the degreasing process is performed.

Next, the first water washing step is performed to completely remove the surfactant component adhered to the surface of the aluminum wheel during the course of the main degreasing step, and the washing is performed at an injection pressure of 1.0 to 2.0 kgf / cm 2 and a conductivity of 500 or less.

The following is the second washing step. Since the surfactant attached to the surface of the aluminum wheel is not completely removed even after the first washing step, the second washing step is performed to completely remove the surfactant component on the surface of the aluminum wheel, 2.0 kgf / cm < 2 > and a conductivity of 200 / cm or less.

Next, in the neutralization step, the aluminum wheel surface is etched by using an etching solution of a sulfuric acid component at an injection pressure of 1.0 to 2.0 kgf / and an acidity of 18 to 36% on the surface of the aluminum wheel subjected to the second water washing step as described above, It is possible to secure the stability of the removal of the oxide film and the subsequent film-forming process.

이하의 이온 교환수를 사용하여 에칭액을 세척하는 공정이다.The following is the third water washing step. In the neutralization step, a third water washing step is performed to wash the etching solution remaining on the surface of the aluminum wheel. The conditions of the third water washing step are an injection pressure of 1.0 to 2.0 kgf /

Of the ion-exchanged water is used to wash the etchant.

이하의 이온 교환수를 사용하여 에칭액이 완전히 제거되도록 세척하는 공정이다.The fourth water washing step is performed to remove the etching solution more completely after the third water washing step, and the conditions are an injection pressure of 1.0 to 2.0 kgf / cm 2, a conductivity of 50

By weight of ion-exchanged water to completely remove the etching solution.

In the coating process, the surface of the aluminum wheel was etched as described above, and the non-chrome liquid having an injection pressure of 1.0 to 2.0 kgf / cm 2, an acidity of 14.5 to 10.5, and a pH of 3.5 to 4.5 was sprayed with the etchant completely removed, Thereby improving the corrosion resistance and adhesion. The reason why the non-chromium solution is used in the coating process is to improve the adhesion of the coating.

이하의 이온 교환수를 사용하여 잔존하는 피막액인 논크롬액을 세척하는 공정이다.In the subsequent fifth water washing step, the spraying pressure of 1.0 to 2.0 kgf / cm 2, the conductivity of 100 to 100 kgf / cm 2 to remove the coating liquid remaining on the surface of the aluminum wheel,

By using the following ion-exchanged water to wash the remaining non-chromium liquid.

이하의 이온 교환수를 사용하여 잔존하는 피막액인 논크롬액을 완전히 세척하는 공정이다.In the sixth washing step, a spraying pressure of 1.0 to 2.0 kgf / cm 2 and a conductivity of 40

By using the following ion-exchanged water to completely wash the remaining non-chromium liquid.

The following pure water washing process is a process for finally cleaning the surface of the aluminum wheel that has been subjected to the sixth washing process as described above and uses ion exchange water having a spraying pressure of 1.0 to 2.0 kgf / cm 2 and a purity (specific resistance) of 0.5 M? / Cm or more Thereby finally cleaning the surface of the aluminum wheel.

The water drying process is a process for removing water remaining on the surface of the aluminum wheel after completion of washing of the aluminum wheel as described above, and completely removing water remaining on the aluminum wheel at a temperature of 140 ± 10 ° C. The pre-treatment step is completed by passing through a water drying step.

The above processes are a general process for producing aluminum wheels, and are a series of processes performed before the undercoating of the present invention.

(4) Substrate coating step

The powder coating process is a process after the pretreatment step consisting of the above-mentioned processes. The powder coating of gray or black powder is applied to the surface of the aluminum wheel by corona electrostatic painting for the purpose of lowering, Lt; / RTI > for 45 minutes.

(5) The intermediate painting step

The intermediate painting step is intended to improve the leveling of the surface of the aluminum wheel, that is, smooth, smooth and glossy, in a dried state after the mixed powder coating is painted on the surface of the aluminum wheel through the undercoating step, Is applied by air spray method and painted in the setting room.

(6) Sputtering step

Specifically, argon (Ar), which is an inert gas, is placed in a vacuum chamber, and electrons emitted from a cathode collide with argon gas to ionize argon, thereby forming an aluminum wheel surface So that a thin film is formed on the surface of the aluminum wheel by exchange of momentum with atoms protruding from the aluminum wheel.

(7) Phase step

The aluminum wheel that has undergone the sputtering process as described above is finally subjected to the upper phase and all the steps are terminated.

In the above-mentioned step, an acrylic powder or an acrylic liquid paint is used to form a transparent coating on the surface of the aluminum wheel. Specifically, the aluminum wheel subjected to the above-described multi-step process and fixing is excellent in surface gloss and has corrosion resistance against salt or brine And acid resistance and abrasion resistance, so that it is possible to increase the production cost as well as the eco-friendly added value corresponding to the chrome wheel.

The present invention provides a powder coating composition for phase inversion which is directly related to the above phase powder coating step and used in this step.

As described above, the present invention provides a top coat paint for protecting a sputtering film which is used in a phase step of an aluminum wheel and which satisfies various physical properties required for a coating material of an aluminum wheel and exhibits excellent metal plating texture.

The powder coating material for an aluminum sputtering wheel according to the present invention comprises 72 to 80 parts by weight of an acrylic resin, 16 to 24 parts by weight of an acryl hardener, and 2 to 4 parts by weight of an additive.

The resin used in the composition of the present invention is an acrylic resin having an epoxide ring end group. In the present invention, one or more kinds of acrylic resins having an epoxy equivalent of 300 to 700 and different curing conditions may be used.

An acrylic hardener is used as a hardener, and Dodecanedioic Acid (DDDA), which is a typical acrylic hardener, is selected and used.

As the acrylic hardener, an acrylic hardener having an epoxy equivalent of 450 to 530 g / eq is used. If the equivalent amount of the acrylic hardener is less than the above range, the dispersibility is lowered. On the contrary, if the above range is exceeded, the hardenability is lowered.

The acrylic hardener is mixed with 16 to 24 parts by weight. If the content of the curing agent is less than the above range, the curing property is lowered and the curing is not properly performed. On the other hand, if the content exceeds the above range, the physical properties of the coating film are lowered.

The additive includes at least one of a dispersant, a pinhole inhibitor, and a light stabilizer.

These additives are used for the purpose of improving the fluidity of the coating material, preventing cratering in which a small crater-shaped hole of the coating film appears, preventing pinholes, controlling sagging, etc., A dispersing agent for prevention of cretering, a photostabilizer and a pinhole inhibitor for minimizing external ultraviolet rays and heat.

The additive is used in an amount of 2 to 4 parts by weight, depending on the intended use.

If the content of the additive is less than the above range, an appropriate effect according to the use of the additive can not be obtained. On the contrary, even if the content exceeds the above range, the increase in the effect is insignificant and uneconomical. In some cases, The additive is preferably used in an amount of 2 to 4 parts by weight, depending on the application.

Hereinafter, a process for preparing the powder coating composition for sputtering in accordance with the present invention will be described.

Step 1

Each composition is weighed, and the acrylic resin, the acrylic hardener, and the additive are improved by using an instrument such as an electronic scale so as to have the composition ratio as described above, and then the mixture is put into a pre-mixer.

Step 2

As a preliminary mixing step, a composition charged into a premixer (Prism Pilot 15) is mixed at 1,000 to 2,000 rpm for 1 to 2 minutes at a high speed.

Step 3

The third step is a dispersion step in which the preliminarily mixed compositions are melt-dispersed using a melt dispersion machine (TwinScrew, ZSK-25) at a temperature of 90 to 100 ° C, and a dispersion is obtained in the form of a chip of an appropriate thickness .

The third step may be carried out twice depending on the dispersed state.

Step 4

In the fourth step, as the crushing step, the prepared chip is cooled and pulverized, and the coarsely pulverized chips are finely pulverized using a pulverizer such as ACM pulverizer or turbo mill. At this time, the particle size of the pulverized powder coating material is pulverized To have an average particle size of 30 to 40 mu m.

Step 5

The fifth step is a filtration step. The pulverized powder coating particles are classified by a vibration classifier (Seebeck) of 60 to 200 mesh to remove the oversized particles, thereby completing the preparation of the powder coating.

The temperature of the melt-extruder is very important in the third step in the production of the paint as described above. When the temperature of the dispersing machine is too high, the curing reaction proceeds in the dispersing machine to cause gelation within the dispersing machine and the storage stability is lowered. Therefore, the temperature of the melting dispersing machine is 90 to 100 ℃ temperature should be maintained.

The color of the sputtering film can be displayed with excellent transparency for the purpose of the present invention and discoloration does not occur even in the cleaning agent to which the strongly acidic solution such as hydrofluoric acid (HF) is added, and for the sputtering coating which gives the metal plating texture, 72 to 80 parts by weight, 16 to 24 parts by weight of an acrylic hardener, and 2 to 4 parts by weight of an additive.

The powder coating composition prepared as described above is applied by electrostatic spray coating so as to have a dry film thickness of about 70 to 100 μm.

The above method is the same as the coating method of the existing powder coating material, and the coated coating material is heat-cured in the indirect hot air type drying furnace.

Examples of the powder coating for the aluminum sputtering wheel of the present invention prepared as described above and comparative examples outside the composition range of the present invention were constructed as follows and comparative tests were conducted.

[Table 1] Raw material composition and content

 ① Acrylic resin: Epoxy Equivalent 540 (Anderson Development Company)

 ② Acrylic hardener: acid value 490 (Dupont)

 (3) Dispersant: PV-5 (Estron chemical), 570 FL (Troy)

 ④ UV-A / Hals: Tinivin 144 (CIBA)

⑤ Pinhole inhibitor: Benzoin (Estron chemical)

The starch product thus mixed was melt-dispersed using a melt-extruder (extruder or kneader, etc.) while heating at 90 to 100 ° C, and then cooled and cooled to form a chip using a compression roller.

The prepared chips were pulverized into particles having a size of 5 to 105 mu m by a pulverizer to prepare the powder coating material of the present invention. The average particle size of the powder coating material of the present invention was adjusted to 33 mu m.

The powder coating material of the present example was coated on an aluminum wheel pretreated with a corona electrostatic powder coating device at an average film thickness of 70 to 100 mu m and then held in a hot air circulating electric oven set at 190 DEG C for 45 minutes to cure . Due to the size, thickness and weight of the wheel, the actual temperature and time for the wheel material to be heated even under these conditions is about 160 ° C for about 20 minutes.

Apply an undercoat paint to the aluminum wheel to a dry film thickness of 70 to 100 μm and cure at 210 ° C for 45 minutes. Thereafter, a liquid transparent coating material was applied to a dry film thickness of about 20 μm, cured at 140 ° C. for 30 minutes, and then coated to a thickness of 0.1 μm using a plasma sputtering system to a dry film thickness of 0.1 μm, The powder coating material of this example is coated and cured at 160 DEG C for 20 minutes so that the thickness is about 70 to 100 mu m.

The aluminum wheel manufactured in the above manner was allowed to stand for 24 hours, and then the gloss and mechanical properties of the coating film were tested. The test method and results are shown in Table 2 below.

[Table 2] Physical properties test items and test methods for paint for wheel

Cleaning test: After spraying the wheel cleaner containing fluoric acid for 4 minutes, wash it with clean water, check the discoloration after air blowing.

Table 3 shows the results of comparison with the coated aluminum wheels of Examples and Comparative Examples of the present invention.

[Table 3] Test results of physical properties of paints for wheel

In these comparisons, the appearance measurement indicates the extent to which the plating texture is realized, and the adhesion, corrosion resistance and moisture resistance show adhesion and corrosion resistance between the formed sputtering layer and the coating layer under the powder coating and the sputtering layer.

Gloss and appearance are comparative evaluation of other products as compared with Comparative Example 1 which is designed as a general-purpose acrylic resin system.

In the case of Example 1 and Example 2 according to the present invention, the physical property test standard of the paint for a wheel is satisfied, and the adhesion with the sputtering film is excellent. Further, by maintaining interlayer adhesion with the sputtering film, there is an effect of improving the salt water repellency and moisture resistance of the product.

As a result of the above test results, it can be seen that the powder coating material of the present invention achieves excellent plating texture unlike the conventional powder coating material, and is remarkably superior in corrosion resistance and moisture resistance than conventional powder coating materials.

The powder coating composition for the aluminum sputtering wheel according to the present invention has been described above.

It will be understood by those skilled in the art that the technical features of the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

Therefore, it should be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, Ranges and equivalents thereof are to be construed as being included within the scope of the present invention.

Claims (6)

72 to 80 parts by weight of at least one acrylic resin, 16 to 24 parts by weight of an acrylic hardener, and 2 to 4 parts by weight of an additive.
The method according to claim 1,
Wherein the acrylic resin is an acrylic resin having an epoxide ring end group.
The method according to claim 1,
Wherein the acrylic resin is an acrylic resin having an epoxy equivalent of 300 to 700 and at least one acrylic resin having the same or different hardness classifications.
The method according to claim 1,
Wherein the acrylic hardener is Dodecanedioic acid (DDDA).
The method according to claim 1 or 4,
Wherein the acrylic hardener has an equivalent weight of 450 to 530. 5. The powder coating composition for an aluminum sputter wheel as claimed in claim 1,
The method according to claim 1,
Wherein the additive comprises at least one of a dispersant, a pinhole inhibitor and a light stabilizer.