AU2005200840B2 - Metallic coating composition for chroming substrates - Google Patents

Description

S(followed by page I a)

IAUSTRALIA

SPATENTS ACT, 1990 SCOMPLETE SPECIFICATION FOR A STANDARD PATENT

ORIGINAL

Name of Applicant: GOODRICH TECHNOLOGY CORPORATION Regulation 3.2 Actual Inventor: Address for service in Australia: Invention Title: Gary D. Goodrich A J PARK, Level 11, 60 Marcus Clarke Street, Canberra ACT 2601, Australia METALLIC COATING COMPOSTION FOR CHROMING

SUBSTRATES

Divisional of Application No. 2002214620 dated 18 October 2001 The following statement is a full description of this invention, including the best method of performing it known to us.

308154_ I.DOC

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SPECIFICATION

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BACKGROUND OF THE INVENTION This invention relates generally to a process for providing a chrome finish onto substrates. Particularly, the invention relates to a process for vacuum metalizing chromium onto metal substrates. Specifically, this invention relates to a two step vacuum metalization 00oo S process for chroming aluminum and steel substrates for automotive parts, for example, for r providing a chrome layer on automatic parts such as vehicle wheels, hub caps, bumpers, and 0 the like.

SThe metalization process of the present invention has specific and sequential steps to produce chromed aluminum and steel automotive parts having superior chrome adhesion characteristics to prevent delaminations and having chemical and road hazard resistant qualities. Although the disclosure herein discusses the process of metalizing chromium in the production of vehicle wheels, other chroming processes as well as the chroming of other metal substrates are within the purview of this invention.

In the past, aluminum and steel vehicle wheels, for example, have traditionally been electroplated to produce chrome wheels. These prior art processes require the wheel rim to be polished to provide a very smooth surface for the chrome plating to be effective. Further, the wheels are pretreated in hazardous chemicals to provide a clean and homogeneous surface for adherence of the chrome plating. The wheels are then coated with up to three different metal coatings with each step requiring the wheel to be submerged in hazardous solutions. The failme rate of these prior art processes is generally high. Additionally, should the chrome plated surface be damaged, corrosion or rust will typically begin rapidly, causing the chrome plating to delaminate from the wheel surface.

Another alternative prior art process has been developed which applies the chrome coating by vacuum metalization, thereby eliminating the application of the decorative coating using hazardous solutions. This prior art process entails applying one or two primer coat compositions to provide a smooth surface and to provide a suitable adhesion for the Cr to be applied. The wheel is then placed into a vacuum metalization chamber where a decorative coating is applied. Subsequently, a coating is applied to protect the metalized layer from environmental elements. The process produces chrome-like finishes on wheels, but not equal to the quality of the plating process and as such has not been accepted by the wheel manufacturers in the United States.

19-MAY-2008 16:32 FROM TO 0061262837999 P.04/12 00 00 In this specification where reference has been made to patent specifications, other external 0 documents, or other sources of information, this is generally for the purpose of providing a context for discussing the features of the invention. Unless specifically stated otherwise, reference to such external documents or such sources of information is not to be construed as an admission that such documents or such sources of information, in any jurisdiction, are prior art or form part of the common general knowledge in the art.

At least preferred embodiments of the present invention have gone some way towards Sovercoming the difficulties and the shortcomings of the prior art. An object of at least preferred "0 embodiments of the present invention is to provide a true chrome finish on wheels and the like that o will be resistant to harsh climatic conditions, or to at least provide the public with a useful choice.

l t A further objective of at least preferred embodiments is to eliminate hazardous materials used 0 O during the application process and to greatly reduce the potential for delamination should the coating be damaged, impacted or scratched, as has been a problem with the prior art, or to at least provide the public with a useful choice. This process is also applicable to any substrate where a durable, decorative, chrome finish is desired on automotive parts, for example, on vehicle wheels, bumpers, hub caps, and the like. Particularly, the object of at least preferred embodiments of the invention is to provide a vacuum metalization process for chroming metal substrates, such as aluminium and steel substrates, or to at least provide the public with a useful choice.

SUMMARY OF THE INVENTION In one aspect, the invention as claimed broadly consists in a coating composition for a prepared aluminium or steel substrate comprising: a) a base coating, said base coating being a hybrid epoxy thermosetting powder coating; b) a first stabilizing metallic layer applied to said base coating via a physical vapour deposition process, said first stabilizing metallic layer comprising a mixture of approximately 80 wt% Nickel and 20 wt% Chromium; c) a second metallic layer applied to said first stabilizing metallic layer, via a physical vapour deposition process, said second metallic layer comprising at least approximately 99.9% pure Chromium; and d) a top protective layer applied to said second metallic layer, said top protective layer being an acrylic thermosetting powder coating.

In another aspect, a coating composition for an aluminium substrate comprising a) an organic base coating; b) a first metallic layer, said first metallic layer comprising a mixture of approximately 50-80 wt Nickel and approximately 50-20 wt Chromium; c) a second metallic 14&'03-1 2 COMS ID No: ARCS-191048 Received by IP Australia: Time 13:28 Date 2008-05-19 19-1AY-2008 16:32 FROM TO 0061262837999 P.05/12 00 o layer applied to said first metallic layer, said second metallic layer comprising at least approximately C 99.9% pure Chromium; and d) an organic top protective coating applied to said second metallic layer.

SIn another aspect, the invention as claimed broadly consists in a coating composition for a substrate comprising: a) a base layer, said base layer being an organic coating selected from the group of organic coatings consisting of hybrid epoxy thermosetting powder coatings and liquid ecoatings; b) a first metallic layer applied on said base layer, said first metallic layer comprising a 0 mixture of approximately 70-80 wt Nickel and approximately 30-20 wt Chromium; c) a 00 0 second metallic layer applied to said first metallic layer, said second metallic layer comprising at least Sapproximately 99.9% pure Chromium; and d) a top layer applied to said second metallic layer, said top layer being selected from the group of organic layers consisting of acrylic thermosetting powder 0 coatings and e-coatings.

There is disclosed herein a process for chroming aluminium and steel substrates. The process of the invention utilizes a vacuum metalizing process which, preferably, comprises four stages: a cleaning or preparation stage utilizing a number of steps, a base coat application stage, a two-step Physical Vapor Deposition (PVD) stage, and a top coat application stage. Each stage utilizes specific process steps and uses particular formulations under specific process step parameters.

An alminm or steel substrate or object, for example a vehicle wheel, to receive a decorativ chme coating is first cleaned to eliminate contaminatnm. The cleaning stage begins by smoothing th wheel to provide a uniform suface roughness. Nxt, a series of washes are perfined to the wheel; if the wheel is almmima in composition, an al in iedeionized wate sohution wash, followed by a deionized (DI) wate rinse, followed by a an-Chromate/DI water solution coating, and flished with another DI water rinse. If the wheel is of a steel composition, tfh non-Cbromate/DI water solution coating is replaced by an Iron Phosphate/city water solution conversion coating followed by a city water rinse. la the cleaning step for either the lumium or steel composition, he wheel is rinsed with a final DI water rinse. The wheel Is then dried using high-pressu filtred air and is subsequenty placed in an ovn to be outgassed. Last, the wheel is allowed to cool down.

The base coat applied in the base coat application stage is preferably an organic, mhemtosting powder or the like and provides a smooth surface for Nickel/Cmrnmim adhesion, however, aninr iccompound may be lized. Altematively, the base coat may be coprised of an lectroplaed coatig, or coatin The wheel and base coat are heated to permit t coating to l t h and flow vetly across the surfaces of the wheel The tepratue is i- i -vt 31 COMS ID No: ARCS-191048 Received by IP Australia: Time 13:28 Date 2008-05-19 thea increased so that the organic powder will crosslink and solidify. The wheel temperature is c' then reduced in preparation for the two-step PVD stage.

To begin the two-step PVD stage, the wheel is placed into a PVD chamber to receive the chrome coating layer. The PVD stage consists of two steps. Both steps take place in 5 vacuum conditions and by a sputtering or similar process, for example. The first step comprises sputtering an approximately 80% Nickel (Ni) and 20% Chromium (Cr) base metal layer onto the base coat on the wheel. The second step comprises sputtering an approximately 00 099.9% pure Chromium layer onto the metal base layer. As known in the art, various PVD and C CVD processes are known utilizing metallic targets in vacuum conditions. Any such known 0 'o processes may be utilized to deposit the Nickel/Chromium and Chromium layers according to CN the teachings of the invention.

The protective top coat applied in the topcoat application stage is preferably a clear, organic, thermosetting powder, although an inorganic compound and means to produce a colored finish may also be utilized. Alternatively, the top coat may be comprised of an electroplated coating, or e-coating. The top coat is applied to the wheel to cover the Chromium layer and is subsequently heated to cause crosslinking and solidification. The wheel is then permitted to cool down.

The vacuum metalization process of the present invention permits a decorative, chrome coating to be applied to a metal object, for example an aluminum or steel wheel, in an environmentally compatible manner without the use of hazardous chemicals and which is resistant to harsh climatic conditions and delamination. These and other benefits of this invention will become clear fom the following description by reference to the drawings.

It is to be understood that all percentages referred to herein are weight percent.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a flow diagram showing the steps of the process of the present invention; and FIGURE 2 is a cross-sectional view of a substrate showing the layers formed thereon from the process of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a process of chroming aluminum and steel substrates, and particularly to the vacuum metalization of chromium onto aluminum or steel substrates.

The process of this invention provides a decorative and durable chrome finish for aluminum or kn Ssteel objects, for example vehicle wheels, hub caps, bumpers, or the like which is conducted in San environmentally compatible manner.

O Although it is within the purview of this invention to provide a vacuum metalization I process for chroming aluminum and steel substrates to produce articles exhibiting strong adhesion qualities of the metalized chrome and useful for a variety of articles, the chroming of an aluminum or steel wheel for automotive use will be used herein to describe the process stages and steps of the invention.

0 SReferring to Figure 1, the four steps comprising the process of the present invention are set forth. The four general steps of the process are as follows: 1) Cleaning or Preparation SStage, 2) Base Coat Application Stage, 3) Two-Step PVD Stage and 4) Top Coat Application SStage.

CLEANING AND PREPARATION STAGE The Cleaning and Preparation Stage 1 as shown in the process flow diagram of Figure 1 is comprised of process steps la-ll. The surface of the substrate is initially smoothed to a roughness not greater than approximately 1.5 mils by any industry accepted process In other words, the smoothness of the substrate surface preferably does not exceed approximately mils, measuring from the valleys to the peaks on the substrate surface. The substrate, for example a wheel, is then placed into a high-pressure blast cabinet, where the surface is roughed evenly with a polishing type blast media with coarseness not greater than approximately a 120 grit This process step provides a substrate surface that is congenial for the adhesion of the base coat application.

The substrate or wheel is next put through a multi-step, spray washer type, pretreatment process, depending on whether the substrate is aluminum or steel, to ensure that all contamination has been removed from the substrate and to provide proper adhesion of the base coat (Ic-li). During the pretreatment process the wheel is held in the vertical position to ensure complete coverage and to prevent puddling in any recessed areas. The first step (Ic) of the pretreatment is an approximately 60 second wash cycle of an approximately 3% to 6% solution, Alkaline and deionized water, is applied at a temperature of approximately 140 0

F.

This cleaning step is to remove any contamination that may be present on the substrate surface.

The next step (ld) is an approximately 30-second cycle of deionized water rinse, applied at ambient temperature. If the wheel is constructed of aluminum, the next step (le) is an approximately 60 second cycle of an approximately 1% to 3% solution, non-Chromate conversion and deionized water coating, is applied at approximately 140F, to insure proper adhesion of the base coat. If the wheel is constructed of steel, the next step (If) is an O approximately 180-second wash cycle of an approximately solution, Iron Phosphate c' and city water conversion coating, applied at approximately 1400F, to insure proper adhesion of the base coat, followed by a city water approximately 60-second rinse step applied at ambient temperature. The next step (Ih) is an approximately 30 second cycle of deionized c s 5 water rinse, applied at ambient temperature and the following step (li) is a final approximately separate deionized water rinse. The deionized water used in the rinse/wash steps

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z- preferably has a mineral content no greater than approximately 25 ppm to ensure that no 00 S contamination is present in any of the solutions or rinses.

cN Excess water is next blown off by filtered air before entering a dry-off oven The wheel is heated in the dry-off oven to a temperature of approximately 275*F to 350°F (1k).

C The latter step serves two purposes: it evaporates any moisture on the wheel left from the pretreatment process and it causes the pores in the aluminum or steel to outgas any contamination and/or trapped vapors. This step insures that the contamination and/or trapped vapors will not release during the heating steps required in the base and top coat application stages. The wheel then enters a cool down chamber where filtered air cools the wheels to an approximate temperature range of approximately 150WF to 250°F in preparation for the base coat application.

The wheel preferably exits the cool down chamber directly into a pressurized clean room, wherein the atmosphere consists of particulates not greater than approximately 10,000 ppm. Personnel working within the clean room should preferably be required to wear a clean room suite and dust mask to prevent introduction of additional airborne contamination from their clothes, body hair, and the like. The remaining steps are also carred out in this clean room environment and under these conditions to protect from airborne contamination. The cleaning and preparation stage steps set forth above are exemplary to provide a proper metal surface for the remaining stages of the process of the invention.

BASE COAT APPLICATION STAGE The Base Coat Application Stage 2 is shown in Figure I to be comprised of steps 2a- 2d. The base coat preferably consists of a hybrid epoxy, thermosetting powder coating or the like. However, the base coat used in this step may be comprised of an organic or inorganic chemical composition. The base coating may also be comprised of an electroplated coating or e-coating. E-coatings ar generally applied in liquid form via an electroplating process whereby the substrate is either submerged in a dip tank under specified electrically charged conditions or is sprayed with the liquid e-coating material and then heated for curing purposes.

O Referring to Figure 1, the wheel is coated in the horizontal face up position to ensure N even and smooth coverage By applying the powder at the elevated temperature of aC approximately 150°F to 250°F, the powder begins to melt on the wheel upon application. This t process step accomplishes several advantages: it ensures that all areas are coated and that the pores of the aluminum or steel are still in an outgased stage, it enables a thinner coat to be applied, and it reduces the time to preheat the metal in the next step. The desired thickness of the base coat is approximately 1.5 to 5.0 mils. The wheel is next preheated to an approximate o temperature range of 285°F to 310°F after which it remains in that temperature range for a period of approximately 8 to 12 minutes During this phase step the powder continues to melt and flow evenly across all wheel surfaces. Temperature fluctuations above the desired range will cause the flow-out process to stop, while fluctuations below can cause thermal shock and effect the smoothness of the surface. Variations in time, outside the parameters will typically result in an uneven, wavy or orange peal type finishes.

The wheel is next preheated to a temperature range of approximately 445F to 4750F, after which it remains at that temperature for a period of approximately 13 to 20 minutes (2c).

During this step the powder crosslinks and solidifies. If the temperature or time is reduced, typically evidenced by a light, transparent brown appearance, the surface will experience some movement during the curing of the top coat stage and thereby cause cracking in the Cr coating.

If the temperature or time exceeds the parameters as typically evidenced by a black, nontransparent appearance, the surface will become too brittle and may separate from the wheel during the top coat stage and/or reduce its ability to absorb impacts causing premature coating failure. A properly cured base coat has a dark, transparent brown appearance on completion of the base coat curing. The wheel is next cooled to a temperature range of approximately 100F to 250°F, in preparation for the metalization process By keeping the wheel at an elevated temperature, the metalization layers adhere better to the organic base coat, for example, and it provides a brighter (lighter color) to the Cr coating.

TWO-STEP PVD STAGE The wheel is next placed into a Physical Vapor Deposition (PVD) chamber for metalization. The chamber is equipped with Ni/Cr targets and Cr targets. Sufficient targets are arranged so that one of each type target will cover 100% of the wheel as the wheel is rotated on its axes in the chamber, to ensure complete coverage. The pressure in the chamber is then reduced to a pressure of approximately 0.2 to 0.75 mTorr to evacuate any moisture, outgas chamber walls and wheel base coat, and to create a vacuum environment. Argon, of approximately 99.99% purity is then injected into the chamber to bring the pressure up to N approximately 2.5 to 3.5 mTorr, in order to create a plasma environment At this step a Sbase metal layer consisting of approximately 50% to 80% Ni and approximately 50% to Cr is applied by sputtering for approximately 10 to 20 seconds at approximately 700 volt, 17 c s 5 amps and 12 kW. These process step parameters are exemplary and vary depending upon the type of PVD machine and power supply utilized in the PVD machine. For example, changes in the power supply would change the time and voltage required. A lower content of Ni and a 00oo 0 higher content of Cr in a target will produce a lighter color on the second (Cr) metalization S layer. The base metal coating of this invention step provides a stable base for the Cr to be applied over. Samples without the Ni/Cr base developed cacks in the final step of heating the N wheel to cure the top coat The pressure in the chamber is then reduced to a pressure of approximately 1.5 to mTorr, in preparation for applying the Cr metal coating. Cr of approximately 99.99% purity is then applied by sputtering for approximately 5 to 10 seconds at approximately 620 volts, 19 amps and 12 kW (step 3b). These process steps are exemplary depending upon PVD machine type, power supply, size of targets and chamber pressure, etc. During the Ni/Cr application the Cr target will be charged in a range of approximately 0.25 kW to 0.3 kW, and during the Cr application the Ni/Cr target is charged in a range of approximately 0.04 kW to 0.05 kW to prevent contamination from each other. The desired thickness of the combined two metal layers is about 350 A to 600 A. On completion ofthe base and top coat the chamber is vented back to atmospheric pressure using compressed air that is heated, dried and filtered. Using the processed air to vent the chamber prevents contamination of the chamber's interior. The wheel is then removed from the vacuum chamber for application of the protective, clear organic top coat, for example. The two-step PVD stage set forth herein is exemplary and the NiCr and Cr layers may be deposited onto the prepared substrate surface in any known manner including for example, by Arc, CVD or similar methods of vacuum metalization. The important aspect of this stage being the use of the sequential NiCr and Cr layers onto the prepared substrate surface.

As known in the art, various PVD and CVD processes are known utilizing metallic targets in vacuum conditions and employing magnetrons to produce magnetic fields for concentrating the deposit of the metal ions to the object For example, a planar magnetron configuration has been found suitable in the two-step PVD process of the present invention.

Thus, a planar magnetron sputtering source or one having a flat or planar shaped target has been found suitable in accordance with the process of this invention. However, other vacuum o metalization processes may also be utilized in the chroming of aluminum and steel substrates c- process of this invention.

TOPCOAT APPLICATION STAGE SThe Topcoat Application Stage 4 as shown in Figure 1 comprises steps 4a-4c. The c-i clear organic top coat application preferably consists of an acrylic, thermosetting powder coating or the like. The purpose of the topcoat is to provide protection to the metal coatings, wear resistance and UV protection. The topcoat may have an organic or inorganic chemical 00 S composition. The top coating may also be comprised of an electroplated coating or e-coating.

-N The e-coating provides a scratch resistant top coat for the chrome layer applied in the two-step o PVD process of the invention. Ecoatings are generally applied in liquid form via an 0 electroplating process whereby the chromed substrate is either submerged in a dip tank under specified electrically charged conditions or is sprayed with the liquid e-coating material and then heated for curing purposes.

The wheel is coated in the horizontal face up position to ensure even and smooth 1- coverage The desired thickness of the coating is in a range of approximately 2.0 to mils. The clear top coat is applied at a temperature range between approximately 80 0 F to 200F. Temperatures exceeding these parameters will cause the Cr layer to darken After application of the clear top coat, the wheel is preheated to an approximate temperature range of 320F to 360 0 F, after which it will remain at that temperature for a period of approximately to 20 minutes During this method step, the powder will crosslink and solidify. The wheel then enters a cool down chamber where filtered air cools the wheels to ambient temperature (4c).

Figure 2 shows a cross-section of the layers formed on the chromed substrate 10 as a result of the process steps of the present invention. The wheel or substrate 11 is shown to have a base coat layer 12, a Ni/Cr metal layer 13, a Cr layer 14, and a top coat layer 15. The base coat 12 is preferably a hybrid epoxy, thermosetting powder or the like. The Ni/Cr layer 13 and the Cr layer 14 are fonned in the two-step PVD process and are, together, preferably approximately 350A to 600 A in thickness. The top coat is preferably an acrylic, thermosetting powder coating or the like, however, organic or inorganic top coat compositions may be utilized as previously discussed.

The discussion above regarding the base coat application stage and the top coat application stage, particularly with respect to Figure 1, relates respectively to the application of a hybrid epoxy, thermosetting powder coating for the base coat and the application of an 19-MY-2008 16:33 FROM TO 0061262837999 P.06/12 Sacrylic thenostting powder coating for the top coat The application of these base coat and 0 -top coat formulations require specific process parameters, temperatures times, etc., as set forth in Figure 1. As also discussed hein, other base coat and top coat fonulations may also Sbe used in the metalization process of the invention. The application parameters of these base coat and top coat formulations would be diffrent from those discussed with respect to Figre 1 and are generally set by the manufacturcs of the coating fonnulations.

Although a clear top coat has been discussed in the process of the invention, various colored tints may also be utilized on the chromed layer produced in this invention. Far 00 0 example, the top coat itself may be tinted with a color, or a color may be provided to the object itself during the PVD process. For example, the itroducion of a gas such as Argon, Nitroge Sor the like in the PVD process, as Iown in the art, will produce a specified color to the object SA wheel coated using the process of the present invention produced the following test results: 1) Salt Spray Test (ASTM B-117) 480+ Hours 2) Adhesion (ASTMD-3359) 100% 3) Pencil Hardness (ASTM D-3363) H-2H 4) Thermal Cycle (GM 264M) Passed In summary, the process of the ptesent invention provides a Preparation Stage a Base Coat Application Stage 2, a Two-Step D Stage 3, and a Top Coat Appcation Stage 4. The process produces a chrome coating on a surface, preferably alminum or steel, of an object suoh as vehicle wheels, hub caps, bampers and the le, on which it is desirable to have a decorative chrome finish. The process of bis invention is conducted without the use of hazardous chemicals, maling it enviomentavly friendly, and produces a hrome finish which is rsistant to the elements and has a redced potential for delaminatim As many changes are possible to the embodiments of the processes of this invention utilizing the teachings thereof, the descriptions above, and the accompanying drawing should be interpreted in the illustrative and not in the limited sense.

The term "comprising" as used in this specification means "consisting at least in part of'.

When interpreting each statement in this specification that includes the term "comprising", features other than that or those prefaced by the term may also be present. Related terms such as "comprise" and "comprises" are to be interpreted in the same manner.

9 COMS ID No: ARCS-191048 Received by IP Australia: Time 13:28 Date 2008-05-19

Claims (3)

19-MY-2008 16:33 FROM TO 0061262837999 P.07.12 0 0 THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS: O 1. A coating composition for a prepared aluminium or steel substrate comprising a) a base coating, said base coating being a hybrid epoxy thermosettiig powder coating; b) a first stabilizing metallic layer applied to said base coating via a physical vapour deposition process, said first stabilizing metallic layer comprising a mixture of approximately wt% Nickel and 20 wt% Chromium; o c) a second metallic layer applied to said first stabilizing metallic layer, via a physical vapour 00 deposition process, said second metallic layer comprising at least approximately 99.9% pure o Chromium; and V) d) a top protective layer applied to said second metallic layer, said top protective layer being 0 o an acrylic thernosetting powder coating. 2. The coating composition of claim 1, wherein said top protective layer is cured at an approximate range of 320-360 0 F. 3. The coating composition of claim 1, wherein said coating composition has a color and wherein said color is provided in said second metallic layer. 4. A coating composition for an aluminium substrate comprising: a) an organic base coating; b) a first metallic layer, said first metallic layer comprising a mixture of approximately

50-80 wt Nickel and approximately 50-20 wt Chromium; c) a second metallic layer applied to said first metallic layer, said second metallic layer comprising at least approximately 99.9% pure Chromium; and d) an organic top protective coating applied to said second metallic layer. The coating composition of claim 4, wherein said top protective coating is selected from the group of protective coatings consisting of acrylic thermosetting powder coatings and e-coatings. 6. The coating composition of claim 4, wherein said base coating is selected from the group of base coatings consisting of hybrid epoxy thermosetting powder coatings, e-coatings and combinations thereof.

146206. .DOC COMS ID No: ARCS-191048 Received by IP Australia: Time 13:28 Date 2008-05-19 19-F)Y-2008 16:33 FROM TO 0061262837q99 P.08/12 0 0 7. The coating composition of claim 4, wherein said first metallic layer and said second O metallic layer are applied via a vapour deposition process. 8. The coating composition of claim 4, wherein said coating composition has a color and wherein said color is provided in said second metallic layer. 9. A coating composition for a substrate comprising: 0 a) a base layer, said base layer being an organic coating selected from the group of organic 0 coatings consisting of hybrid epoxy thermosetting powder coatings and liquid e-coatings; o b) a first metallic layer applied on said base layer, said first metallic layer comprising a t) mixture of approximately 70-80 wt Nickel and approximately 30-20 wt Chromium; o c) a second metallic layer applied to said first metallic layer, said second metallic layer comprising at least approximately 99.9% pure Chromium; and d) a top layer applied to said second metallic layer, said top layer being selected from the group of organic layers consisting of acrylic thermosetting powder coatings and e-coatings. The coating composition of claim 9, wherein said first metallic layer comprises a mixture of approximately 80 wt Nickel and 20 wt Chromium. 11. The coating composition of claim 9, wherein said first metallic layer and said second metallic layer are applied via a physical vapour deposition process and wherein said top layer is selected from the group of layers consisting of acrylic thermosetting powder coatings coatings and e-coatings and wherein said base layer is selected from the group of base layers consisting of hybrid epoxy thermosetting powder coatings, e-coatings and combinations thereof. 12. The coating composition of claim 9, wherein said top layer is an acrylic thermosetting powder coating and wherein said base layer is a hybrid epoxy thernosetting powder coating. 13. The coating composition of claim 9, wherein said substrate is a metaL 14. The coating composition of claim 1, wherein the metal is aluminium or steel. The coating composition of claim 9, wherein said coating composition has a color. 11 1421)63_ .lL)CX COMS ID No: ARCS-191048 Received by IP Australia: Time 13:28 Date 2008-05-19 P. 09/12 19-MAY-2008 16:33 FROM TO 0061262837999 00 0 0 ci 0 00 0 0 ci 0 0 ci The coating composition of claim 15, wherein said color is provided in said top layer. A coating composition of any one of claims 1 to 16, substantially as herein described. 12 1462)6, 1.l)(l: COMS ID No: ARCS-191048 Received by IP Australia: Time 13:28 Date 2008-05-19