TWI618761B - Method for surface treatment of composite article - Google Patents

Abstract

A surface treatment method for a composite member, which is suitable for surface treatment of a composite member made of metal and plastic, the composite member having an exposed metal surface and a plastic surface, the method comprising the steps of: covering the entire surface of the composite member Lacquering to form a protective layer; electrolytically removing the protective layer of the metal surface to expose the metal surface and retain the protective layer on the plastic surface; in the state where the plastic surface is covered with the protective layer, the physical gas phase Depositing a metal layer on the surface of the metal; and immersing the composite in a paint stripper to remove the protective layer on the surface of the plastic and simultaneously removing the protective layer deposited on the protective layer during the physical vapor deposition process Metal layer.

Description

Surface treatment method of composite parts

The invention relates to a surface treatment method, in particular to a surface treatment method for a metal and non-metal composite component.

In the existing electronic products, a composite member made of metal and plastic is commonly used, for example, a casing, usually after the metal is formed, and then the formed metal member and the plastic are molded into a composite member.

In order to make the metal surface can present different colors and make the appearance of the object more beautiful, the metal surface can usually be plated with a physical vapor deposition (PVD) process, and the metal of different materials can exhibit different metallic colors.

If the metal layer is plated on the metal surface of the composite by the physical vapor deposition process, the plastic surface is also plated with a metal layer, which not only affects the color of the plastic surface, but also makes the function of the plastic itself incapable of appearing. For example, insulation function.

Therefore, how to form a metal layer on the metal surface of the composite member by the physical vapor deposition process and keep the plastic surface not plated to the metal layer is a problem to be solved.

It is an object of the present invention to provide a surface treatment method for a composite member which can solve the aforementioned problems.

Therefore, in some embodiments, the surface treatment method of the composite member of the present invention is suitable for surface treatment of a composite member made of metal and plastic, the composite member having an exposed metal surface and a plastic surface, the method comprising the following steps :. Coating the protective lacquer on the entire surface of the composite member to form a protective layer; electrolytically removing the protective layer of the metal surface to expose the metal surface and retain the protective layer on the plastic surface; coating the plastic surface to protect the surface a metal layer is coated on the surface of the metal by a physical vapor deposition process; and the composite is immersed in a paint stripper to remove the protective layer on the surface of the plastic while removing the physical vapor phase A metal layer deposited on the protective layer during the deposition process.

Thus, in some embodiments, the composite member has an adjacent metal surface and a non-metallic surface, the method comprising the steps of: at least the adjacent metal of the composite member The surface and the non-metal surface are coated with a protective layer; the protective layer of the metal surface is electrolytically removed to expose the metal surface and retain the protective layer on the non-metal surface; and the non-metal surface is covered with the protective layer, Coating a metal layer on the metal surface and the non-metal surface; and removing the protective layer on the non-metal surface and the metal layer on the protective layer.

The invention has at least the following effects: by electrolytically removing the protective layer of the metal surface, the metal surface can be completely exposed and the plastic surface can be completely protected by the protective layer, so that after the metal surface is formed into a metal layer, the protective layer for removing the plastic surface can be utilized. The metal layer of the plastic surface is removed. In this way, after the metal surface of the composite member is plated with the metal layer, the plastic surface can still maintain the original appearance without losing its original function and appearance color.

Referring to FIG. 1 and FIG. 2, an embodiment of a surface treatment method for a composite member of the present invention is suitable for surface treatment of a composite member made of metal and plastic. The composite member has an exposed metal surface and a plastic surface, and the method includes the following step:

Step S1, coating the entire surface of the composite member with a protective lacquer to form a protective layer;

Step S2, removing the protective layer of the metal surface by electrolysis to expose the metal surface and retain a protective layer on the plastic surface;

Step S3, coating a metal layer on the metal surface by a physical vapor deposition process in a state where the plastic surface is covered with a protective layer;

In step S4, the composite member is immersed in a paint stripper to remove the protective layer on the plastic surface and simultaneously remove the metal layer deposited on the protective layer in the physical vapor deposition process.

Referring to FIG. 2, in the embodiment, a composite member including a metal plate 1 and a plastic block 2, and the metal plate 1 and the plastic block 2 each have a metal surface 10 and a plastic surface 20 adjacent to each other as an example to explain the implementation steps. And in this case, the composite member can be a casing of an electronic device.

Before the step S1 is performed, the composite member may be first washed and dried to remove surface dirt and impurities.

In step S1, a protective layer 3 is formed on the entire surface of the composite member by, for example, coating a protective lacquer, that is, the surface 10 of the metal plate 1 and the surface 20 of the plastic block 2 are covered with a protective lacquer, and on the surface 10 of the metal plate 1 A protective layer 3 is formed with the surface 20 of the plastic block 2. The protective paint can be sprayed onto the surface of the composite by spraying. The protective paint may be, for example, a enamel paint, a polyurethane (PU) paint, an epoxy resin (EPOXY) paint, an Acrylic paint, a high temperature resistant paint containing boron nitride titanium oxide, a Teflon paint, or the like. Spray the protective paint evenly on the surface of the composite part about 5 to 50 microns, then dry and cure in the environment of 100 to 180 degrees Celsius. If the UV-curable paint is used, it can be dried in the environment of 70 degrees Celsius before using ultraviolet rays. The light source is solidified.

In step S2, the protective layer 3 of the metal surface 10 is electrolytically removed to expose the metal surface 10 and retain the protective layer 3 on the plastic surface 20. Specifically, in step S2, the composite member coated with the protective layer 3 is placed in an electrolytic cell (not shown), and the metal plate 1 is used as an electrode and the surface 10 of the metal plate 1 is made of a metal conductive property. The protective layer 3 is electrolyzed and removed. At the same time, since the plastic block 2 is not electrically conductive, the protective layer 3 of the surface 20 of the plastic block 2 can be retained. In the present embodiment, the components used in the electrolytic solution include barium carbonate, sodium hydroxide, potassium hydroxide, a surfactant, and the like, and the components are environmentally friendly, and do not contain an organic solvent such as an ether, an alcohol, or an aromatic solvent. By removing the protective layer 3 of the metal surface 10 by electrolysis, the metal surface 10 and the plastic surface 20 can be accurately distinguished, and the protective layer 3 of the metal surface 10 can be completely removed without damaging the protective layer 3 of the plastic surface 20. The plastic surface 20 is allowed to be completely protected.

In addition, in a variant embodiment, a protective layer 3 may also be formed on the surface of the composite member by using, for example, a masking tape, a masking tape, a UV-type dry film or other suitable non-metallic material or product or method, and the metal surface may also be removed by electrolysis. 10 protective layer 3.

After the step S2 is completed, the composite member can be washed and dried to remove the residual electrolyte and impurities on the surface of the composite member.

In step S3, a metal layer 4 is coated on the metal surface 10 by a physical vapor deposition (PVD) process in a state where the plastic surface 20 is covered with the protective layer 3. Specifically, after the composite member is subjected to an electrolytic process, the surface 10 of the metal plate 1 is exposed, and the surface 20 of the plastic block 2 is still covered with the protective layer 3. Generally, in the physical vapor deposition process, the entire surface of the composite member is deposited. The metal layer 4, that is, on the surface 10 of the metal plate 1 and the protective layer 3 covering the surface 20 of the plastic block 2, deposits a metal layer 4. The physical vapor deposition process may be, for example, evaporation or sputtering, and the metal layer 4 formed by the physical vapor deposition process may have a strong bonding force with the surface of the object to be plated (for example, the metal plate 1 of the embodiment), and may be plated. The film layer is more widely used, and the formed film layer has more and more color types, and is suitable for improving the appearance decorative property of the object to be plated, and the film formed by the general physical vapor deposition process has better corrosion resistance. Sex and abrasion resistance, long service life.

In step S4, the composite member is immersed in a paint stripper to remove the protective layer 3 of the plastic surface 20 and simultaneously remove the metal layer 4 deposited on the protective layer 3 in the physical vapor deposition process. In this embodiment, the paint stripper is a commercially available paint remover, and the paint remover corresponding to the protective paint may be selected, and the composite member is dipped in the paint strip for about 5 to 30 minutes to make the plastic block 2 The protective layer 3 of the surface 20 is detached, and at the same time, the metal layer 4 on the protective layer 3 is separated from the surface of the plastic block 2 together with the protective layer 3, so that the surface 10 of the metal plate 1 is covered with the metal layer 4, and in the plastic block. The surface 20 does not cover the metal layer 4 to maintain its original surface, thereby not affecting the appearance and function of the plastic surface 20.

After step S4, the composite member can be further cleaned and dried to remove the paint remover and impurities on the residual surface.

In this embodiment, the material of the metal plate 1 may be, for example, a copper alloy, a magnesium alloy, a titanium alloy or a stainless steel, but is not limited thereto. In a variant embodiment, the composite member may also be made of a metal and other non-metallic materials, such as non-conductive materials such as glass, wood, ceramics, and the like. That is, the plastic material of the embodiment can be replaced by other non-metal materials. In a variant embodiment, the method of coating the metal layer 4 may employ, for example, water plating.

In summary, by removing the protective layer 3 of the metal surface 10 by electrolysis, it can be ensured that the metal surface 10 can be completely exposed and the plastic surface 20 can be completely protected by the protective layer 3, so that the metal surface 10 can be removed after forming the metal layer 4. The protective layer 3 of the plastic surface 20 removes the metal layer 4 of the plastic surface 20. Thus, after the metal surface 20 of the composite member is plated with the metal layer 4, the plastic surface 10 can still maintain the original appearance without losing its original function and appearance color.

Furthermore, the present invention also discloses a surface treatment method for a composite member, comprising the steps of: providing a composite member having an adjacent metal surface 10 and a non-metal surface 20; adjacent metal surfaces of the composite member 10 and the non-metallic surface 20 form a non-metallic layer, such as the aforementioned protective layer 3; and the non-metallic layer of the metal surface 10 is electrolytically removed to expose the metal surface 10 and continue to retain the non-metallic layer on the non-metallic surface 20. In other words, by utilizing the characteristics of the electrolytic reaction occurring only on the metal surface, the present invention can precisely define the boundary between the adjacent metal surface 10 and the non-metal surface 20 to remove only the non-metal layer on the metal surface 10 without affecting The non-metallic layer of the non-metallic surface 20 is destroyed.

However, the above is only the embodiment of the present invention, and the scope of the invention is not limited thereto, and all the equivalent equivalent changes and modifications according to the scope of the patent application and the patent specification of the present invention are still The scope of the invention is covered.

S1‧‧‧ steps
S2‧‧‧ steps
S3‧‧‧ steps
S4‧‧‧ steps
1‧‧‧Metal sheet
2‧‧‧ plastic block
3‧‧‧Protective layer
4‧‧‧metal layer
10‧‧‧Metal surface
20‧‧‧Plastic surface

Other features and advantages of the present invention will be apparent from the embodiments of the present invention, wherein: Figure 1 is a flow block diagram of an embodiment of a surface treatment method for a composite member of the present invention; and Figure 2 is A schematic flow diagram of an embodiment.

Claims (10)

A surface treatment method for a composite member, which is suitable for surface treatment of a composite member made of metal and plastic, the composite member having an exposed metal surface and a plastic surface, the method comprising the steps of: covering the entire surface of the composite member Lacquering to form a protective layer; electrolytically removing the protective layer of the metal surface to expose the metal surface and retain the protective layer on the plastic surface; in the state where the plastic surface is covered with the protective layer, the physical gas phase Depositing a metal layer on the surface of the metal; and immersing the composite in a paint stripper to remove the protective layer on the surface of the plastic and simultaneously removing the protective layer deposited on the protective layer during the physical vapor deposition process Metal layer. The surface treatment method of the composite member according to claim 1, further comprising the step of washing and drying the composite member before forming the protective layer. The surface treatment method of the composite member according to claim 2, further comprising the step of washing and drying the composite member after electrolytically removing the protective layer of the metal surface. The surface treatment method of the composite member according to claim 3, further comprising the step of washing and drying the composite member after removing the protective layer on the plastic surface. The surface treatment method of the composite member according to claim 1, wherein the protective layer is formed by spraying. A surface treatment method for a composite member, the composite member having an adjacent metal surface and a non-metal surface, the method comprising the steps of: coating a protective layer on the adjacent metal surface and the non-metal surface of the composite member; Removing the protective layer of the metal surface by electrolysis to expose the metal surface and retain the protective layer on the non-metal surface; and coating the metal surface and the non-metal surface in a state where the non-metal surface is covered with the protective layer a metal layer; and the protective layer on the non-metallic surface and the metal layer on the protective layer. A surface treatment method for an electronic device casing, the casing having an adjacent metal surface and a non-metal surface, the method comprising the steps of: covering the adjacent metal surface and the non-metal surface of the casing Removing the protective layer of the metal surface by electrolysis to expose the metal surface and retain the protective layer on the non-metal surface; in the state where the non-metal surface is coated with the protective layer, on the metal surface and the non-metal surface Depositing a metal layer; and removing the protective layer on the non-metal surface and the metal layer on the protective layer. A surface treatment method for a composite member, the composite member having an adjacent metal surface and a non-metal surface, the method comprising the steps of: coating a protective layer on the adjacent metal surface and the non-metal surface of the composite member; The composite member is placed in an electrolytic cell to electrolytically remove the protective layer on the metal surface; in the state in which the non-metal surface is coated with the protective layer, a metal layer is coated on the metal surface and the non-metal surface; and the non-metal is removed The protective layer on the metal surface and the metal layer on the protective layer. A surface treatment method for a composite member, comprising the steps of: providing a composite member having an adjacent metal surface and a non-metal surface; forming a non-metal on the adjacent metal surface and non-metal surface of the composite member And removing the non-metallic layer of the metal surface by electrolysis to expose the metal surface and retain the non-metal layer on the non-metal surface. A surface treatment method for a composite member, comprising the steps of: providing a composite member having an adjacent metal surface and a non-metal surface; forming a non-metal on the adjacent metal surface and non-metal surface of the composite member And placing the composite into an electrolytic cell to electrolytically remove the non-metallic layer of the metal surface and retain the non-metallic layer on the non-metallic surface.