U.S. patent application number 12/208440 was filed with the patent office on 2009-06-18 for surface treatment process for coloring metal articles.
This patent application is currently assigned to SHENZHEN FUTAIHONG PRECISION INDUSTRY CO., LTD.. Invention is credited to LIANG-YU CAO, LI-XIA HU, FA-HONG ZENG.
Application Number | 20090152120 12/208440 |
Document ID | / |
Family ID | 40751784 |
Filed Date | 2009-06-18 |
United States Patent
Application |
20090152120 |
Kind Code |
A1 |
CAO; LIANG-YU ; et
al. |
June 18, 2009 |
SURFACE TREATMENT PROCESS FOR COLORING METAL ARTICLES
Abstract
A surface treatment process for coloring metal articles includes
following steps. In a first step, a metal article is anodized to
form a first anodic oxide layer including a first portion and a
second portion on the original metal article. In a second step, the
anodized metal article is dyed. In a third step, the first portion
of the first anodic oxide layer is removed from the anodized metal
article to partially expose a metal body of the anodized metal
article. In a fourth step, the exposed metal body of the anodized
metal article is anodized to form a second anodic oxide layer. In a
fifth step, the exposed metal body of the metal article is
dyed.
Inventors: |
CAO; LIANG-YU; (Shenzhen
City, CN) ; ZENG; FA-HONG; (Shenzhen City, CN)
; HU; LI-XIA; (Shenzhen City, CN) |
Correspondence
Address: |
PCE INDUSTRY, INC.;ATT. Steven Reiss
458 E. LAMBERT ROAD
FULLERTON
CA
92835
US
|
Assignee: |
SHENZHEN FUTAIHONG PRECISION
INDUSTRY CO., LTD.
ShenZhen City
CN
FIH (HONG KONG) LIMITED
Kowloon
HK
|
Family ID: |
40751784 |
Appl. No.: |
12/208440 |
Filed: |
September 11, 2008 |
Current U.S.
Class: |
205/173 |
Current CPC
Class: |
C25D 11/02 20130101;
C25D 11/30 20130101; C25D 11/26 20130101; C25D 11/34 20130101; C25D
11/246 20130101; C25D 11/243 20130101; C25D 5/02 20130101 |
Class at
Publication: |
205/173 |
International
Class: |
C25D 11/22 20060101
C25D011/22 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 14, 2007 |
CN |
200710203082.X |
Claims
1. A surface treatment process for coloring metal articles,
comprising: providing a metal article; anodizing the metal article,
thereby forming a first anodic oxide layer on the original metal
article; dyeing the anodized metal article; coating the first
anodic oxide layer with a light curable ink; attaching a flexible
film to the anodized metal article, with the flexible film covering
the light curable ink coating, the flexible film having a
transparent portion and a patterned portion, the patterned portion
being exposed and opaque to light; exposing the metal article to
cure the light curable ink coating covered by the transparent
portion of flexible film, with the light curable ink coating
covered by the patterned portion of flexible film remaining
uncured; removing the uncured light curable ink coating, thereby
the first anodic oxide layer having a first portion exposed to the
environment and a second portion covered by the cured light
sensitive coating; removing the first portion of the first anodic
oxide layer form the anodized metal article, thereby exposing a
metal body of the anodized metal article to the environment;
anodizing the exposed metal body; and dyeing the exposed metal
body.
2. The surface treatment process as claimed in claim 1, wherein the
metal article is made of a metal selected from the group consisting
of aluminum, titanium, magnesium, steel, and any alloy thereof.
3. The surface treatment process as claimed in claim 1, further
comprising pretreatment pre-treating pre-anodized article by
degreasing the surface of the metal article and then polishing the
surface of the metal article.
4. The surface treatment process as claimed in claim 1, wherein the
anodizing process is carried out in an electrolyte containing about
180 to 200 g/l sulphuric acid and metal ions less than 20 g/l, at a
direct current of about 11 volts to 13 volts for 30 to 50
minutes.
5. The surface treatment process as claimed in claim 1, wherein the
thickness of the light curable ink coating is about 10 to 50
microns.
6. The surface treatment process as claimed in claim 1, wherein
during the step of exposing the metal article to cure the light
curable ink coating, the anodized metal article is exposed using an
exposure machine at exposure energy of about 100 to 150
mj/cm.sup.2.
7. The surface treatment process as claimed in claim 1, wherein the
step of removing the uncured light curable ink coating is carried
out in a photographic developer.
8. The surface treatment process as claimed in claim 1, wherein the
first portion of the first anodic oxide layer is removed from the
anodized metal article by a chemical etching process.
9. The surface treatment process as claimed in claim 8, wherein
during the chemical etching process, the anodized metal article is
immersed into sodium hydroxide solution at a concentration of about
40 g/l.
10. The surface treatment process as claimed in claim 1, further
comprising a step of removing the cured light curable coating
covering the second portion of the first anodic oxide layer by
using a release agent.
11. A surface treatment process for coloring metal articles,
comprising steps of: anodizing a metal article, thereby forming a
first anodic oxide layer including a first portion and a second
portion on the original metal article; dyeing the anodized metal
article; removing a portion of the first anodic oxide layer from
the anodized metal article to partially expose a portion of the
metal body of the anodized metal article; anodizing the exposed
metal body of the anodized metal article to form a second anodic
oxide layer; and dyeing the exposed metal body of the metal
article.
12. The surface treatment process as claimed in claim 11, further
comprising a step of applying a protective ink coating onto the
first anodic oxide layer before removing the first portion of the
first anodic oxide layer, the protective ink coating covering the
second portion of the first anodic oxide layer.
13. The surface treatment process as claimed in claim 12, wherein
the step of applying a protective ink coating comprising: forming a
light curable ink coating onto the first anodic oxide layer;
attaching a flexible film to the anodized metal article, with the
flexible film covering the light curable ink coating, the flexible
having a transparent portion and a patterned portion, the patterned
portion being exposed and opaque to light; exposing the metal
article to cure the light curable ink coating covered by the
transparent portion of flexible film, with the light curable ink
coating covered by the patterned portion of flexible film remaining
uncured; removing the uncured light curable ink coating.
14. The surface treatment process as claimed in claim 11, wherein
the metal article is made of a metal selected from the group
consisting of aluminum, titanium, magnesium, steel, and any alloy
thereof.
15. The surface treatment process as claimed in claim 11, further
comprising pre-treating the pre-anodized material by degreasing the
surface of the metal article and then polishing the surface of the
metal article.
16. The surface treatment process as claimed in claim 13, wherein
the thickness of the light curable ink coating is about 10 to 50
microns.
17. The surface treatment process as claimed in claim 13, wherein
the first portion of the first anodic oxide layer is removed from
the anodized metal article by a chemical etching process.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to surface treatment processes
for coloring metal articles.
[0003] 2. Description of Related Art
[0004] Metal articles made of, e.g., aluminum, magnesium, titanium,
or alloys thereof, have various mechanical attributes making them
popular for a wide range of applications and in many industries
such as housings for mobile devices. Metal articles usually undergo
surface treatment for improving decorative quality or surface
durability.
[0005] Anodizing is a surface treatment carried out in an anodizing
solution for improving the decorative quality and/or surface
durability of the metal articles. During anodization of the metal
articles, a porous anodic oxide film is formed over the surface of
the metal articles. The anodized metal articles are often
subsequently colored to obtain decorative appearances. The coloring
of the metal articles can be carried out in a dye solution.
However, the color of the paint particles cannot be altered during
coloring of the metal articles. Thus only a single-color appearance
can be obtained by a combination of the anodizing process and the
coloring process. However, consumers desire multi-colored metal
articles.
[0006] Therefore, a surface treatment process for coloring metal
articles is desired.
DETAILED DESCRIPTION OF THE INVENTION
[0007] In a present embodiment, a surface treatment process for
coloring metal articles may include the following steps.
[0008] In a first step, a metal article made of at least one of
steel, aluminum, titanium, magnesium, or alloys thereof is
provided. Degreased using an alkali-based cleaning solution removes
oil stains on the metal article.
[0009] In a second step, the metal article is chemically polished
to smooth and clear its surface. During the chemical polishing
step, the metal article 10 is immersed in a chemical polishing
solution typically containing phosphoric acid and sulfuric acid.
Chemical-mechanical polishing (CMP) processes are well known.
[0010] In a third step, the metal article is processed in a first
anodizing process carried out in an electrolyte containing about
180 to 200 g/l (gram per liter) sulphuric acid and metal ions less
than about 20 g/l, using a direct current in an approximate range
from 11 volts to 13 volts for 30 to 50 minutes. As electrolysis
proceeds, a first anodic metal oxide layer grows on the metal
article. After anodizing, the surface of the anodized metal article
is effectively the first anodic oxide layer on the original metal
article.
[0011] In a fourth step, the metal article is colored in a first
dyeing process. The first dyeing process can be a chemical coloring
process.
[0012] In a fifth step, the anodized metal article is processed
using in a first sealing process to improve anti-contamination
performance and anti-corrosion performance of the first anodic
oxide layer of the anodized metal article. The first sealing
process is carried out, for example in a nickel salt solution, e.g.
nickel acetate or nickel fluoride.
[0013] In a sixth step, the anodized metal article is coated by a
light curable ink to form a light curable coating with a thickness
of about 10 to 50 microns. The light curable coating may entirely
cover the first anodic oxide layer of the anodized metal
article.
[0014] In a seventh step, a flexible film is provided. The flexible
film includes a transparent portion and a patterned portion. The
patterned portion has been exposed and has a light opaque coating
formed thereon. The flexible film is applied onto the anodized
metal article to cover the light curable coating. A vacuum
generator can be employed to draw out the air contained between the
flexible film and the anodized metal article, thereby enabling the
flexible film to be closely attached to the anodized metal
article.
[0015] In an eighth step, the anodized metal article is exposed
using an exposure machine at exposure energy of about 100 to 150
mj/cm.sup.2 (micron joule per square centimeters). During exposure
of the anodized metal article, one portion of the light curable
coating covered by the transparent portion of the flexible film is
cured. The other portion of the light curable coating covered by
the patterned portion of the flexible film remains uncured.
[0016] In a ninth step, the flexible film is removed from the
anodized metal article. The anodized metal article is then immersed
into a photographic developer to remove the uncured light curable
coating. Thus, the first anodic oxide layer has a first portion
exposed to the environment and a second portion covered by the
cured light curable coating.
[0017] In a tenth step, the first portion of the first anodic oxide
layer is removed from the anodized metal article by a chemical
etching process. During the chemical etching process, the anodized
metal article is immersed into a chemical etching solution, e.g.,
sodium hydroxide solution at a concentration of about 40 g/l, to
remove the first portion of the first anodic oxide layer, thereby
exposing the metal body of the anodized metal article. The cured
light curable coating may protect the second portion of the first
anodic oxide layer from being removed. Understandably, a laser
etching process can also be employed to remove the first portion of
the first anodic oxide layer.
[0018] In an eleventh step, the anodized metal article is processed
in a second anodizing process. The exposed metal body of the
anodized metal article is anodized, thereby forming a second anodic
oxide layer on the exposed metal body of the anodized metal
article.
[0019] In a twelfth step, the metal article is colored in a second
dyeing process, to color the surface of the anodized metal article
defined by the second anodic oxide layer. The second dyeing process
can be a chemical coloring process.
[0020] In a thirteenth step, the second anodic oxide layer of the
anodized metal article is sealed in a second sealing process that
may be carried out in a nickel salt solution, e.g. nickel acetate
or nickel fluoride.
[0021] In a fourteenth step, the cured light curable coating
covering the second portion of the first anodic oxide layer is
removed by a release agent. As the metal article is processed in
two different dyeing processes (i.e., the first dyeing process and
the second dyeing process), a metal article with a surface having
two-colors can be obtained.
[0022] It should be understood that the steps 6-14 can be repeated,
as desired to thereby obtain a metal article having a surface with
more than two colors.
[0023] It should be also understood, however, that even though
numerous characteristics and advantages of the present embodiments
have been set forth in the foregoing description, together with
details of the structures and functions of the embodiments, the
disclosure is illustrative only, and changes may be made in detail,
especially in matters of shape, size, and arrangement of parts
within the principles of the invention to the full extent indicated
by the broad general meaning of the terms in which the appended
claims are expressed.
* * * * *