CA1299135C - Process for electrolytically coloring aluminum material - Google Patents
Process for electrolytically coloring aluminum materialInfo
- Publication number
- CA1299135C CA1299135C CA000528589A CA528589A CA1299135C CA 1299135 C CA1299135 C CA 1299135C CA 000528589 A CA000528589 A CA 000528589A CA 528589 A CA528589 A CA 528589A CA 1299135 C CA1299135 C CA 1299135C
- Authority
- CA
- Canada
- Prior art keywords
- aluminum material
- material substrate
- substrate according
- nickel
- electrolytically coloring
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Electroplating And Plating Baths Therefor (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process for electrolytically coloring aluminum material in which the aluminum material is subjected to an anodic treatment to form an anodic coating thereon, the resultant anodized aluminum is subjected to an AC, DC or AC-DC
electrolytic treatment in an electrolytic coloring bath containing a coloring agent comprising at least a nickel salt and a zinc salt, a chelating reagent for nickel ions, a supporting electrolyte and adjusted to above pH 4.5 to produce a colored aluminum material having a desired color ranging from a gray series to black.
A process for electrolytically coloring aluminum material in which the aluminum material is subjected to an anodic treatment to form an anodic coating thereon, the resultant anodized aluminum is subjected to an AC, DC or AC-DC
electrolytic treatment in an electrolytic coloring bath containing a coloring agent comprising at least a nickel salt and a zinc salt, a chelating reagent for nickel ions, a supporting electrolyte and adjusted to above pH 4.5 to produce a colored aluminum material having a desired color ranging from a gray series to black.
Description
lZ9913S
The present invention relates to a process for elec-trolytically coloring aluminum or an aluminum alloy hereafter generally called "aluminum material~, in which, firstly, the aluminum material is sub;ected to an anodizing treatment to form an anodized aluminum material, and, secondly, the anodized aluminum material is subjected to an electrolytic coloring treatment simply by adjusting electrolytic conditions, and thereby there is produced on the anodized surface thereof a desired color ranging from any gray of a gray series through the gray series, to black.
In U.S. Pat~nt No. 3,382,160 there is disclosed a ~ h~s beer~
'~ process in which after the aluminum material ~ subjected to an electrolytic treatment in a sulfuric acid bath so as to form an anodic coating thereon, the resultant anodized alu-minum material is sub;ected to an electrolytic treatment in an electrolytic coloring bath containing such metallic salts as a nickel salt, a cobalt salt, or a stannous salt such that such salts may be pr0cipitatad in innumerable fine pores of the anodic coating thereof to produce a bronze color series thereon.
This electrolytic coloring of the anodized aluminum material is called a "secondary electrolytically coloring pro-cess" and has been widely used for manufacturing colored alu-minum material products for building, construction and other applications. However, all of the colored aluminum products obtained industrially by using various types of conventional electrolytic coloring baths as mentioned above have only lim-ited colors or tints ranging from a bronze series to black, and consequently cannot meet the latest demand for diversified or varied colored alumin~m products.
The present invention provides for an improvement in electrolytic coloring bath compositions for achieving not only ~299135 improvement in the corrosion resisting properties and abrasion resisting properties of aluminum products, but also obtaining varied colored aluminum products. According to the present invention the so-called second~ electrolytic treatment is carried out using an electrolytic coloring hath containing a combination of a nickel salt and a zinc salt, as an essential coloring agent, preferably, in a specific weight ratio thereo~, of l.0 to 0~5, additionally containing chelating reagent for nickel ions and a suitable supporting electrolyte.
According to the present invention there is provided a process for electrolytically coloring an aluminum material substrate comprising: (a) anodizing an aluminum material substrate; (b) introducing said anodized aluminum material into a bath comprising a nickel salt, a zinc salt, a chelating reagent for nickel ions and magnesium sulfate, at a pH of 4.5 or greater, and in which the compounding ratio of nickel salt to zinc salt is 1:0.1 to 0.5; and (c) electrolyzing said substrate.
Thus, according to the pre~ent invention, firstly an aluminum material is subjected to an anodic treatment to ~em an anodic coating thereon, and, secondly, the resultant anodized aluminum material is subjected to an electrolytic coloring treatment in an electrolytic coloring bath containing, as principal constituents, a nickel salt, preferably, nickel sulfate, ammonium nickel sulfate, or nickel sulphamate, and a zinc salt, preferably zinc sulfate or zinc chloride, and additionally containing, as a chelating reagent for nickel ions at least one type selected from the group comprising gluconic acid, malonic acid, sulfosalicylic acid, tartaric acid, citric aci.d, sulfophthalic acid, sulfamlc acid and boric acid and as a supporting electrolyte, ammonium sulfate and magnesium sul-fate and adjusted to a pH of at least 4.5, so that the precip-itated and dispersed degree of particles of the nickel salt into the fine pores of the anodic coating can be increased, and thereby there can be produced varied colored aluminum products having such a color range of from a gray series including a pure gray or a gray slightly tinged with blusish green to black which range it has not been possible to produce using the conventional electrolytic coloring process. In addition, it has also been found that the corrosion resisting properties of the colored coating of the aluminum product thus r ~
produced io better than those of the colored aluminum product having the bronze series colored coating obtained by the conventional process as above, and the abrasion resisting properties and the covering power produced by the process are also excellent as compared with the conventional processes.
' " c ~- e lq ,l, .,~ .~
The term "mas]~ing reagent" for nickel ions has the same meaning as that used in analytical chemistry, and refers to any chemical compound that acts to stabilize nickel ions in the base so that electrolytic deposition speed of nickel ions may be appropriate when the nickel ions are deposited together with the electrolytic deposition of the zinc ions as described below.
Further, the nickel salt and the zinc salt consti-tuting the principal constituents of the bath act to give to the aluminum material a desired color selected from the colors or tints in the range of from a gray series to black as a result of being with the progress of the deposition thereof in the fine pores of the anodic coating of the aluminum material at the time of the secondary electrolytic coloring treatment.
In this case, when a small amo~mt of molybdate is added to the principal coloring constituents, this acts to assist in giving the gray series to the aluminum material while the secondary electrolytic treatment is being carried out.
Accordingly, it is effective to add, as the principal constituents, in a bath a small amount of molybdate, such as ammonium molybdate, beside the nickel salt and the zinc salt.
For carrying out the secondary electrolytic treatment, there is used a direct current, an alternating current of dual currents of ~C and DC. It has been found preferable that the voltage used be about 10-30 V, and the bath temperature about 15-30C.
When the pH value of the electrolytic coloring bath is adjusted to below 4.5, it becomes difficult to effect the codeposition of the metals into the fine pores of the anodic coating, and consequently the coloring effect of this invention cannot be fully obtained. Accordingly, it is desirable that the pH value should be adjusted to be kept above 4.5, and preferably within the range of 5-9.
The reason why the colored coating of aluminum material ranging from a simple gray through a gray series to black which has excellent corrosion resisting properties can be obtained by the process of the present invention is considered to be as follows:-Aluminum itself is an extremely basic metal, and has a strong negative polarity automatically at the time of use in the electrolytic treatment. Accordingly, metallic positive ions in the bath are strongly attracted to the aluminum, while forming a concentration gradient thereof in the bath.
In this sense, the secondary electrolytic coloring process is similar to a plating technique, and according to detailed reports (Electrochemistry 45, No. 2, 1977 and 47 No. 2, 1979 by Mr. Kurachi Mitsuo et al. on codeposition from a plating ba-th containing, as its princlpal constituents, nickel sulfate and zinc sulfate, but adjusted to p~ 2-4, there is some description relating to the codeposition of the nickel and zinc metals, but there can hardly be obtained gray colored plated products.
According to this invention, in spite of the fact that where the electrolytic coloring bath is so prepared as to contain a nickel salt and a zinc salt in the concentration ratio of 1:0.25 and to adjust its pH to 6.5, for instance, it has been found by a chemical analysis that the ratio or deposited nickel metal and deposited zinc metal in the fine pores or cells of the anodic coating of the aluminum material w2~ 1:1 (atomic ratio) as a result of applying to the forego-ing bath an alternating current at 14 v for 3 minutes, and a gray colored aluminum product is obtained. From the above, it is considered that on the codeposition of the zinc and nickel, the deposition of zinc is superior to the deposition of nickel, and when the AC electrolysis is further continued or the deposition condition is properly ad~usted, the deposition rate of the zinc is further increased and at the same tlme the dispersibility of nickel salt is increased, and thereby a desired varied color of a gray series can be obtained adjustably.
Mr. Kurachi Mitsuo et al. reported his study about the codeposited materials in the foregoing reports, in which he presumed that they are intermetallic compounds, such as NiZn3 or Ni5Zn21, and also in the foregoing process of this invention these intermetallic compounds are considered to be contained among such materials deposited in the anodic coating that give thereto varied colors in the range of from a gray series to black of this invention.
1299~5 The corrosion resisting properties of the colored aluminum material obtained by the process of the present invention are better than-~ha~ of the colored aluminum material obtained by the conventional nickel salt electrolytic bath. This is considered to be due to the fact that the C~, ~ /" ,!, "~
presence of the m~6~-lng reagent for nickel ions in the bath causes the zinc to deposit preferentially on the anodic coating of the aluminum and protect the aluminum from corrosion. The inventor has made a CASS anticorrosion test according to JIS - H 8681, on the colored aluminum product obtained by the process of this invention and the colored aluminum product obtained by the conventional nickel salt electrolytic bath, for 8 hours, 16 hours, 24 hours and 32 hours to obtain the results as shown in the following Table 1.
Each sample to be tested was 9 microns in coating thickness, and the secondary electrolytic treatment for producing each sample was carried out at 15 V of AC, for 3 minutes.
Table 1 CASS test time ¦ Bath of the process Conventional bath of the present invention 8 hours R.N. 10 R.N. 10 16 hours R.N. 10 R.N. 10 24 hours R.N. 10 R.N. 9.8 32 hours ~ R.N. 10 R.N. 9.5 "R.N." stand for Rating Number.
It is appreciated from the results of Table 1 that the colored aluminum material obtained by the process of this invention was R.N. 10, even after 32 hours from the starting of the test, and did not display any corrosion, whereas the conventional one was R.N ! 9 . 8 after the lapse of time of 24 hours and displayed a slight corrosion, and thus the corrosion ~299~35 thereof was advanced with time.
The present invention will be further illustrated by way of the following Examples.
Example 1 A sheet of 2S aluminum material was subjected to an anodic treatment by a conventional method, for instance, in sulfuric acid bath containing 15% by weight of sulfuric acid at ambient temperature for 30 to 50 minutes, with a direct current, to form thereon an anodic coating of 10 ~m in thickness. Then, with nickel as the other polarity electrode, the same was subjected to an AC secondary electrolytic treatment in an electrolytic coloring bath (pH
6.5) comprising 30 g/~ of boric acid, 20 g/~ of nickel sulfate, 6 g/Q of zinc sulfate, 25 g/Q of magnesium sulfate and 40 g/Q of a~monium sulfate. There was produced a light gray colored aluminum material finish at 17 V, for 2 minutes, a slight blue-greenish gray colored one at the same voltage, for 4 minutes, and a black colored one at 15 V for 12 minutes, respectively.
Example 2 A 43S aluminum material was subjected to an anodic treatment in a sulfuric acid bath by the conventional method as above to form thereon an anodic coating of 15 ~m in thickness. Then, with carbon as the other polarity electrode, the same was subjected to an AC secondary electrolytic treatment in an electrolytic coloring bath (pH
7.3) comprising 20 g/~ of sulfamic acid, 25 g/~ of nickel sulfamate, 5 g/~ of zinc chloride, 0.5 g/~ of ammonium molybdate, 25 g/Q of magnesium sulfate and 30 g/~ of ammonium p ~2991~5 sulfate. There was produced a light gray colored aluminum material finish at 17 V for 30 seconds, a gray colored one at the same voltage as above for 1 minute, a deep gray colored one at the same voltage for 3 minutes, and a black colored one at 14 v for 13 minutes.
Example 3 An _ l,lO0 P - H 24 aluminum material was subjected to an anodic treatment in a sulfuric acid bath by a conven-tional method to form an anodic coating of 10 microns in thickness. Then, with nickel as the other polarity electrode, nr.~ I~e r I C~ I
,~^ the ~a~e was subjected to an AC secondary electrolytic treatment in a coloring electrolytic bath (pH 7.8) comprising 20 g/Q of sulfosalicylic acid, 20 g/~ of nickel sulfate, 4 g/Q of zinc sulfate, 25 g/~ of magnesium sulfate and 40 g~R
of ammonium sulfate.
As a result, there was produced a light gray colored aluminum material finish at 15 V for l minute, a simple gray colored one at the same voltage as above for 2 minutes, a slight blue-greenish deep gray colored one at the same voltage for 3 minutes and a black colored one at the same voltage for 12 minutes.
Example 4 An _ 6,063S - T 5 aluminum material was subjected to an anodic treatment in a sulfuric acid bath by a conventional method to form an anodic coating of 15 micron thickness.
~ er ~
Then, with nickel as the other polarity electrode, the ~
was sub;ected to an AC secondary electrolytic treatment in an electrolytic coloring bath (pH 5.3) comprising 15 g/~ of sul-fophthalic acid 30 g/~ of nickel sulfate, 6 g~ of zinc sul-fate, 30 g/~ of magnesium sulfate and 25 g/~Q of ammonium sulfate. As a result, there was produced a simple gray colored aluminum material finish at 18 V for 2 minutes, and a black colored one at the same voltage as above for ten minutes.
Example 5 The same aluminum material as used in Example 4 was 1299~35 used and the same was treated with the same manner as in Example 4 except for that the anodized aluminum materlal was subjected to a DC secondary electrolytic treatment at 10 V for 40 seconds. A colored aluminum material finish having gray tinged with slight blue-green was obtained.
Example 6 A 2S aluminum material was sub;ected to an anodic treatment in a sulfuric acid bath by a conventional method to form an anodic coating of about 14 ~m in thickness. Then, f er ~
with carbon as the other polarity electrode, the~e was sub-jected to a secondary electrolytic treatment at an AC and DC
double currents in an electrolytic coloring bath (pH 7.5) com-prising 30 g/~ of gluconic acid, 25 g/~ of nickel sulfate, 15 g/~ of ammonium sulfate, 25 g/JQ of magnesium sulfate and 5 g/~ of zinc sulfate. As a result, there was produced a blue-greenish gray colored aluminum material finish at 10 V
for 2 minutes and a simple gray colored one at 12 V for 2 minutes and a black colored one at 14 V for 7 minutes.
The present invention relates to a process for elec-trolytically coloring aluminum or an aluminum alloy hereafter generally called "aluminum material~, in which, firstly, the aluminum material is sub;ected to an anodizing treatment to form an anodized aluminum material, and, secondly, the anodized aluminum material is subjected to an electrolytic coloring treatment simply by adjusting electrolytic conditions, and thereby there is produced on the anodized surface thereof a desired color ranging from any gray of a gray series through the gray series, to black.
In U.S. Pat~nt No. 3,382,160 there is disclosed a ~ h~s beer~
'~ process in which after the aluminum material ~ subjected to an electrolytic treatment in a sulfuric acid bath so as to form an anodic coating thereon, the resultant anodized alu-minum material is sub;ected to an electrolytic treatment in an electrolytic coloring bath containing such metallic salts as a nickel salt, a cobalt salt, or a stannous salt such that such salts may be pr0cipitatad in innumerable fine pores of the anodic coating thereof to produce a bronze color series thereon.
This electrolytic coloring of the anodized aluminum material is called a "secondary electrolytically coloring pro-cess" and has been widely used for manufacturing colored alu-minum material products for building, construction and other applications. However, all of the colored aluminum products obtained industrially by using various types of conventional electrolytic coloring baths as mentioned above have only lim-ited colors or tints ranging from a bronze series to black, and consequently cannot meet the latest demand for diversified or varied colored alumin~m products.
The present invention provides for an improvement in electrolytic coloring bath compositions for achieving not only ~299135 improvement in the corrosion resisting properties and abrasion resisting properties of aluminum products, but also obtaining varied colored aluminum products. According to the present invention the so-called second~ electrolytic treatment is carried out using an electrolytic coloring hath containing a combination of a nickel salt and a zinc salt, as an essential coloring agent, preferably, in a specific weight ratio thereo~, of l.0 to 0~5, additionally containing chelating reagent for nickel ions and a suitable supporting electrolyte.
According to the present invention there is provided a process for electrolytically coloring an aluminum material substrate comprising: (a) anodizing an aluminum material substrate; (b) introducing said anodized aluminum material into a bath comprising a nickel salt, a zinc salt, a chelating reagent for nickel ions and magnesium sulfate, at a pH of 4.5 or greater, and in which the compounding ratio of nickel salt to zinc salt is 1:0.1 to 0.5; and (c) electrolyzing said substrate.
Thus, according to the pre~ent invention, firstly an aluminum material is subjected to an anodic treatment to ~em an anodic coating thereon, and, secondly, the resultant anodized aluminum material is subjected to an electrolytic coloring treatment in an electrolytic coloring bath containing, as principal constituents, a nickel salt, preferably, nickel sulfate, ammonium nickel sulfate, or nickel sulphamate, and a zinc salt, preferably zinc sulfate or zinc chloride, and additionally containing, as a chelating reagent for nickel ions at least one type selected from the group comprising gluconic acid, malonic acid, sulfosalicylic acid, tartaric acid, citric aci.d, sulfophthalic acid, sulfamlc acid and boric acid and as a supporting electrolyte, ammonium sulfate and magnesium sul-fate and adjusted to a pH of at least 4.5, so that the precip-itated and dispersed degree of particles of the nickel salt into the fine pores of the anodic coating can be increased, and thereby there can be produced varied colored aluminum products having such a color range of from a gray series including a pure gray or a gray slightly tinged with blusish green to black which range it has not been possible to produce using the conventional electrolytic coloring process. In addition, it has also been found that the corrosion resisting properties of the colored coating of the aluminum product thus r ~
produced io better than those of the colored aluminum product having the bronze series colored coating obtained by the conventional process as above, and the abrasion resisting properties and the covering power produced by the process are also excellent as compared with the conventional processes.
' " c ~- e lq ,l, .,~ .~
The term "mas]~ing reagent" for nickel ions has the same meaning as that used in analytical chemistry, and refers to any chemical compound that acts to stabilize nickel ions in the base so that electrolytic deposition speed of nickel ions may be appropriate when the nickel ions are deposited together with the electrolytic deposition of the zinc ions as described below.
Further, the nickel salt and the zinc salt consti-tuting the principal constituents of the bath act to give to the aluminum material a desired color selected from the colors or tints in the range of from a gray series to black as a result of being with the progress of the deposition thereof in the fine pores of the anodic coating of the aluminum material at the time of the secondary electrolytic coloring treatment.
In this case, when a small amo~mt of molybdate is added to the principal coloring constituents, this acts to assist in giving the gray series to the aluminum material while the secondary electrolytic treatment is being carried out.
Accordingly, it is effective to add, as the principal constituents, in a bath a small amount of molybdate, such as ammonium molybdate, beside the nickel salt and the zinc salt.
For carrying out the secondary electrolytic treatment, there is used a direct current, an alternating current of dual currents of ~C and DC. It has been found preferable that the voltage used be about 10-30 V, and the bath temperature about 15-30C.
When the pH value of the electrolytic coloring bath is adjusted to below 4.5, it becomes difficult to effect the codeposition of the metals into the fine pores of the anodic coating, and consequently the coloring effect of this invention cannot be fully obtained. Accordingly, it is desirable that the pH value should be adjusted to be kept above 4.5, and preferably within the range of 5-9.
The reason why the colored coating of aluminum material ranging from a simple gray through a gray series to black which has excellent corrosion resisting properties can be obtained by the process of the present invention is considered to be as follows:-Aluminum itself is an extremely basic metal, and has a strong negative polarity automatically at the time of use in the electrolytic treatment. Accordingly, metallic positive ions in the bath are strongly attracted to the aluminum, while forming a concentration gradient thereof in the bath.
In this sense, the secondary electrolytic coloring process is similar to a plating technique, and according to detailed reports (Electrochemistry 45, No. 2, 1977 and 47 No. 2, 1979 by Mr. Kurachi Mitsuo et al. on codeposition from a plating ba-th containing, as its princlpal constituents, nickel sulfate and zinc sulfate, but adjusted to p~ 2-4, there is some description relating to the codeposition of the nickel and zinc metals, but there can hardly be obtained gray colored plated products.
According to this invention, in spite of the fact that where the electrolytic coloring bath is so prepared as to contain a nickel salt and a zinc salt in the concentration ratio of 1:0.25 and to adjust its pH to 6.5, for instance, it has been found by a chemical analysis that the ratio or deposited nickel metal and deposited zinc metal in the fine pores or cells of the anodic coating of the aluminum material w2~ 1:1 (atomic ratio) as a result of applying to the forego-ing bath an alternating current at 14 v for 3 minutes, and a gray colored aluminum product is obtained. From the above, it is considered that on the codeposition of the zinc and nickel, the deposition of zinc is superior to the deposition of nickel, and when the AC electrolysis is further continued or the deposition condition is properly ad~usted, the deposition rate of the zinc is further increased and at the same tlme the dispersibility of nickel salt is increased, and thereby a desired varied color of a gray series can be obtained adjustably.
Mr. Kurachi Mitsuo et al. reported his study about the codeposited materials in the foregoing reports, in which he presumed that they are intermetallic compounds, such as NiZn3 or Ni5Zn21, and also in the foregoing process of this invention these intermetallic compounds are considered to be contained among such materials deposited in the anodic coating that give thereto varied colors in the range of from a gray series to black of this invention.
1299~5 The corrosion resisting properties of the colored aluminum material obtained by the process of the present invention are better than-~ha~ of the colored aluminum material obtained by the conventional nickel salt electrolytic bath. This is considered to be due to the fact that the C~, ~ /" ,!, "~
presence of the m~6~-lng reagent for nickel ions in the bath causes the zinc to deposit preferentially on the anodic coating of the aluminum and protect the aluminum from corrosion. The inventor has made a CASS anticorrosion test according to JIS - H 8681, on the colored aluminum product obtained by the process of this invention and the colored aluminum product obtained by the conventional nickel salt electrolytic bath, for 8 hours, 16 hours, 24 hours and 32 hours to obtain the results as shown in the following Table 1.
Each sample to be tested was 9 microns in coating thickness, and the secondary electrolytic treatment for producing each sample was carried out at 15 V of AC, for 3 minutes.
Table 1 CASS test time ¦ Bath of the process Conventional bath of the present invention 8 hours R.N. 10 R.N. 10 16 hours R.N. 10 R.N. 10 24 hours R.N. 10 R.N. 9.8 32 hours ~ R.N. 10 R.N. 9.5 "R.N." stand for Rating Number.
It is appreciated from the results of Table 1 that the colored aluminum material obtained by the process of this invention was R.N. 10, even after 32 hours from the starting of the test, and did not display any corrosion, whereas the conventional one was R.N ! 9 . 8 after the lapse of time of 24 hours and displayed a slight corrosion, and thus the corrosion ~299~35 thereof was advanced with time.
The present invention will be further illustrated by way of the following Examples.
Example 1 A sheet of 2S aluminum material was subjected to an anodic treatment by a conventional method, for instance, in sulfuric acid bath containing 15% by weight of sulfuric acid at ambient temperature for 30 to 50 minutes, with a direct current, to form thereon an anodic coating of 10 ~m in thickness. Then, with nickel as the other polarity electrode, the same was subjected to an AC secondary electrolytic treatment in an electrolytic coloring bath (pH
6.5) comprising 30 g/~ of boric acid, 20 g/~ of nickel sulfate, 6 g/Q of zinc sulfate, 25 g/Q of magnesium sulfate and 40 g/Q of a~monium sulfate. There was produced a light gray colored aluminum material finish at 17 V, for 2 minutes, a slight blue-greenish gray colored one at the same voltage, for 4 minutes, and a black colored one at 15 V for 12 minutes, respectively.
Example 2 A 43S aluminum material was subjected to an anodic treatment in a sulfuric acid bath by the conventional method as above to form thereon an anodic coating of 15 ~m in thickness. Then, with carbon as the other polarity electrode, the same was subjected to an AC secondary electrolytic treatment in an electrolytic coloring bath (pH
7.3) comprising 20 g/~ of sulfamic acid, 25 g/~ of nickel sulfamate, 5 g/~ of zinc chloride, 0.5 g/~ of ammonium molybdate, 25 g/Q of magnesium sulfate and 30 g/~ of ammonium p ~2991~5 sulfate. There was produced a light gray colored aluminum material finish at 17 V for 30 seconds, a gray colored one at the same voltage as above for 1 minute, a deep gray colored one at the same voltage for 3 minutes, and a black colored one at 14 v for 13 minutes.
Example 3 An _ l,lO0 P - H 24 aluminum material was subjected to an anodic treatment in a sulfuric acid bath by a conven-tional method to form an anodic coating of 10 microns in thickness. Then, with nickel as the other polarity electrode, nr.~ I~e r I C~ I
,~^ the ~a~e was subjected to an AC secondary electrolytic treatment in a coloring electrolytic bath (pH 7.8) comprising 20 g/Q of sulfosalicylic acid, 20 g/~ of nickel sulfate, 4 g/Q of zinc sulfate, 25 g/~ of magnesium sulfate and 40 g~R
of ammonium sulfate.
As a result, there was produced a light gray colored aluminum material finish at 15 V for l minute, a simple gray colored one at the same voltage as above for 2 minutes, a slight blue-greenish deep gray colored one at the same voltage for 3 minutes and a black colored one at the same voltage for 12 minutes.
Example 4 An _ 6,063S - T 5 aluminum material was subjected to an anodic treatment in a sulfuric acid bath by a conventional method to form an anodic coating of 15 micron thickness.
~ er ~
Then, with nickel as the other polarity electrode, the ~
was sub;ected to an AC secondary electrolytic treatment in an electrolytic coloring bath (pH 5.3) comprising 15 g/~ of sul-fophthalic acid 30 g/~ of nickel sulfate, 6 g~ of zinc sul-fate, 30 g/~ of magnesium sulfate and 25 g/~Q of ammonium sulfate. As a result, there was produced a simple gray colored aluminum material finish at 18 V for 2 minutes, and a black colored one at the same voltage as above for ten minutes.
Example 5 The same aluminum material as used in Example 4 was 1299~35 used and the same was treated with the same manner as in Example 4 except for that the anodized aluminum materlal was subjected to a DC secondary electrolytic treatment at 10 V for 40 seconds. A colored aluminum material finish having gray tinged with slight blue-green was obtained.
Example 6 A 2S aluminum material was sub;ected to an anodic treatment in a sulfuric acid bath by a conventional method to form an anodic coating of about 14 ~m in thickness. Then, f er ~
with carbon as the other polarity electrode, the~e was sub-jected to a secondary electrolytic treatment at an AC and DC
double currents in an electrolytic coloring bath (pH 7.5) com-prising 30 g/~ of gluconic acid, 25 g/~ of nickel sulfate, 15 g/~ of ammonium sulfate, 25 g/JQ of magnesium sulfate and 5 g/~ of zinc sulfate. As a result, there was produced a blue-greenish gray colored aluminum material finish at 10 V
for 2 minutes and a simple gray colored one at 12 V for 2 minutes and a black colored one at 14 V for 7 minutes.
Claims (27)
1. A process for electrolytically coloring an aluminum material substrate comprising: (a) anodizing an aluminum material substrate; (b) introducing said anodized aluminum material into a bath comprising a nickel salt, a zinc salt, a chelating reagent for nickel ions and magnesium sulfate, at a pH of 4.5 or greater, and in which the compounding ratio of nickel salt to zinc salt is 1:0.1 to 0.5; and (c) electrolyzing said substrate.
2. A process for electrolytically coloring an aluminum material substrate comprising: (a) anodizing an aluminum material substrate; (b) introducing said anodized aluminum material into a bath comprising a nickel salt, a zinc salt, a molybdate salt, a chelating reagent for nickel ions and magnesium sulfate, at a pH of 4.5 or greater, and in which the compounding ratio of nickel salt to zinc salt is 1:0.1 to 0.5; and (c) electrolyzing said substrate.
3. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein said nickel salt is selected from the group consisting of nickel sulfate, ammonium nickel sulfate and nickel sulfamate.
4. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein said nickel salt is selected from the group consisting of nickel sulfate, ammonium nickel sulfate and nickel sulfamate.
5. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein said zinc salt is selected from the group consisting of zinc sulfate and zinc chloride.
6. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein said zinc salt is selected from the group consisting of zinc sulfate and zinc chloride.
7. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein the molibdate salt is ammonium molybdate.
8. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein said chelating reagent for nickel ions is at least one selected from the group consisting of gluconic acid, malonic acid, sulfosalicylic acid, tartaric acid, citric acid, sulfophthalic acid, sulfamic acid, and boric acid.
9. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein said chelating reagent for nickel ions is at least one selected from the group consisting of gluconic acid, malonic acid, sulfosalicylic acid, tartaric acid, citric acid, sulfophthalic acid, sulfamic acid, and boric acid.
10. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein said electrolysis process according to step (C) is performed using alternating current.
11. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein said electrolysis process according to step (C) is performed using alternating current.
12. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein said electrolysis process according to step (C) is performed using direct current.
13. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein said electrolysis process according to step (C) is performed using direct current.
14. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein said electrolysis process according to step (C) is performed using dual current of alternating and direct current.
15. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein said electrolysis process according to step (C) is performed using dual current of alternating and direct current.
16. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein the colored coating produced has a color ranging from a grey series to black.
17. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein the colored coating produced has a color ranging from a grey series to black.
18. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein the second electrode in the second electrolysis step is selected from the group consisting of carbon and nickel.
19. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein the second electrode in the second electrolysis step is selected from the group consisting of carbon and nickel.
20. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein the pH of the bath is within the range of 7.3 to 7.8.
21. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein the pH of the bath is 7.3.
22. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein the pH of the bath is 7.5.
23. A process for electrolytically coloring an aluminum material substrate according to claim 1, wherein the pH of the bath is 7.8.
24. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein the pH of the bath is within the range of 7.3 to 7.8.
25. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein the pH of the bath is 7.3.
26. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein the pH of the bath is 7.5.
27. A process for electrolytically coloring an aluminum material substrate according to claim 2, wherein the pH of the bath is 7.8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000528589A CA1299135C (en) | 1984-12-17 | 1987-01-30 | Process for electrolytically coloring aluminum material |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59264494A JPS61143593A (en) | 1984-12-17 | 1984-12-17 | Method for electrolytically coloring aluminum material |
| CA000528589A CA1299135C (en) | 1984-12-17 | 1987-01-30 | Process for electrolytically coloring aluminum material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1299135C true CA1299135C (en) | 1992-04-21 |
Family
ID=25671221
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000528589A Expired - Fee Related CA1299135C (en) | 1984-12-17 | 1987-01-30 | Process for electrolytically coloring aluminum material |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1299135C (en) |
-
1987
- 1987-01-30 CA CA000528589A patent/CA1299135C/en not_active Expired - Fee Related
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4021315A (en) | Process for electrolytic coloring of the anodic oxide film on aluminum or aluminum base alloys | |
| CA2028107A1 (en) | Process for surface treatment of aluminum or aluminum alloy | |
| DE2638305A1 (en) | METHODS AND MEANS FOR CHEMICAL SURFACE FINISHING OF METALS | |
| US4470897A (en) | Method of electroplating a corrosion-resistant zinc-containing deposit | |
| Sheasby et al. | The electrolytic colouring of anodized aluminium | |
| US20060257683A1 (en) | Stainless steel electrolytic coating | |
| CA1129805A (en) | Electrodeposition of ruthenium-iridium alloy | |
| KR890001378B1 (en) | Method of making an article having a layer of a nickelphosphorus alloy and coated with a protective layer | |
| US3664932A (en) | Objects of aluminum and alloys of aluminum having colored coatings and process | |
| US3795590A (en) | Process for coloring aluminum and alloys of aluminum having an anodized surface | |
| US4806226A (en) | Process for electrolytically coloring aluminum material | |
| US4299671A (en) | Bath composition and method for electrodepositing cobalt-zinc alloys simulating a chromium plating | |
| CA1299135C (en) | Process for electrolytically coloring aluminum material | |
| GB2116588A (en) | Electroplated zinc-cobalt alloy | |
| US4591416A (en) | Chromate composition and process for treating zinc-nickel alloys | |
| US2355505A (en) | Electrodeposition of bright zinc | |
| EP0121361B1 (en) | Colouring process for anodized aluminium products | |
| JPS6141998B2 (en) | ||
| JPS604920B2 (en) | Method for manufacturing black rhodium plated articles with good wear resistance | |
| EP0843027B1 (en) | Method for electrolytically coloring aluminum material | |
| US4138294A (en) | Acid zinc electroplating process and composition | |
| US2307551A (en) | Method of producing a white, platinumlike color chromium plate and the product thereof and bath therefor | |
| EP0229665B1 (en) | Specular product of golden tone and method for manufacturing same | |
| EP0607119B1 (en) | Process for deposing layers of or containing lead, electrolyte for carrying out the process and use of tensides in acidic lead electrolytes | |
| RU2377344C1 (en) | Electrolyte and method to apply tin-cobalt alloy coats |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |