JPH0588314B2

JPH0588314B2 -

Info

Publication number: JPH0588314B2
Application number: JP7125086A
Authority: JP
Inventors: Yoshihide Sano; Soei Koizumi; Yasuhiro Okano; Takeshi Ataya; Masaaki Yamashita; Yasuhisa Tajiri; Akira Enatsu; Takahiro Kubota
Original assignee: Nippon Kokan Ltd
Current assignee: JFE Engineering Corp
Priority date: 1985-06-24
Filing date: 1986-03-31
Publication date: 1993-12-21
Also published as: JPS6289879A

Description

[Brief explanation of drawings]

第１図はSb³⁺濃度と白色度の関係グラフ、第
２図はCo²⁺濃度と白色度の関係グラフ、第３図
はPHと白色度の関係グラフ、第４図はNi²⁺／
Sb³⁺モル比と白色度の関係グラフ、第５図は
Co²⁺／Sb³⁺モル比と白色度の関係グラフ、第６
図はFe³⁺／Sb³⁺モル比と白色度の関係グラフ、
第７図は塩水噴霧時間と白錆発生面積の関係グラ
フである。 Figure 1 is a graph of the relationship between Sb ³⁺ concentration and whiteness, Figure 2 is a graph of the relationship between Co ²⁺ concentration and whiteness, Figure 3 is a graph of the relationship between PH and whiteness, and Figure 4 is a graph of Ni ²⁺ /
Figure 5 is a graph showing the relationship between Sb ³⁺ molar ratio and whiteness.
Relationship graph between Co ²⁺ /Sb ³⁺ molar ratio and whiteness, 6th
The figure is a graph of the relationship between Fe ³⁺ /Sb ³⁺ molar ratio and whiteness.
FIG. 7 is a graph showing the relationship between the salt water spray time and the area where white rust occurs.

Claims

[Claims] 1 Contains 0.2 to 5 g/l of antimony ions a and 10 to 100 g/l of one or more metal ions selected from metal ions b consisting of nickel ions, iron ions, and cobalt ions. A blackening treatment solution for zinc or zinc alloy comprising an acidic aqueous solution having the metal ion b/antimony ion a molar ratio of 5 to 110 and a pH of 6 or less. 2. The blackening treatment solution for zinc or zinc alloy according to claim 1, wherein the metal ion b/antimony ion a molar ratio is 25 to 70. 3 Zinc or zinc alloy, antimony ion a
0.2 to 5 g/l and 10 to 100 g/l of one or more types selected from metal ion b consisting of nickel ion, iron ion, and cobalt ion, and the metal ion b/the antimony ion A black zinc or zinc alloy, characterized in that it is treated with an acidic aqueous solution having a molar ratio of 5 to 110 and a pH of 6 or less to form a black film, and then a phosphoric acid film is applied to the surface thereof. processing method. 4. The method for blackening zinc or zinc alloy according to claim 3, wherein the metal ion b/antimony ion a molar ratio is 25 to 70. 5 Zinc or zinc alloy, antimony ion a
0.2 to 5 g/l and 10 to 100 g/l of one or more types selected from metal ion b consisting of nickel ion, iron ion, and cobalt ion, and the metal ion b/the antimony ion After forming a black film by treating with an acidic aqueous solution having a molar ratio of 25 to 70 and a pH of 6 or less,
A method for blackening zinc or zinc alloy, which comprises applying a chromate film with a Cr film amount of 1 to 1000 mg/m ² on the surface thereof. 6 Zinc or zinc alloy, antimony ion a
0.2 to 5 g/l and 10 to 100 g/l of one or more types selected from metal ion b consisting of nickel ion, iron ion, and cobalt ion, and the metal ion b/the antimony ion After forming a black film by treating with an acidic aqueous solution having a molar ratio of 25 to 70 and a pH of 6 or less,
1. A method for blackening zinc or zinc alloy, comprising applying an alkali silicate film with a thickness of 0.01 to 3 μm on the surface thereof. 7 Zinc or zinc alloy, antimony ion a
0.2 to 5 g/l and 10 to 100 g/l of one or more types selected from metal ion b consisting of nickel ion, iron ion, and cobalt ion, and the metal ion b/the antimony ion After forming a black film by treating with an acidic aqueous solution having a molar ratio of 25 to 70 and a pH of 6 or less,
A method for blackening zinc or zinc alloy, the method comprising applying a resin film to the surface of the zinc or zinc alloy. 8 Zinc or zinc alloy, antimony ion a
0.2 to 5 g/l and 10 to 100 g/l of one or more types selected from metal ion b consisting of nickel ion, iron ion, and cobalt ion, and the metal ion b/the antimony ion After forming a black film by treating with an acidic aqueous solution having a molar ratio of 25 to 70 and a pH of 6 or less,
A method for blackening zinc or zinc alloy, which comprises applying a chromate film with a Cr film amount of 1 to 1000 mg/m ² on the surface thereof, and further applying a resin film thereon. [Industrial Application Field] The present invention relates to a blackening treatment liquid used for continuously and quickly treating zinc or zinc alloys, particularly zinc or zinc alloy metal strip steel sheets, to form a black film on the surface thereof. and its method. The zinc or zinc alloy used in the present invention includes Al, Co, Cr, Ni, Mg,
It also includes those plated with one or more metals selected from In, Ti, Pb, Sn, Mo, Fe, and Mn. [Prior Art] Recently, attempts have been made to continuously and quickly blacken zinc or zinc alloy metal strip steel sheets, or to apply them to automobile parts, electronic parts, refrigerator parts, etc. by subjecting them to blackening treatment or further clear coating them. As a blackening treatment method, a black chromate method is disclosed in Japanese Patent Application Laid-Open No. 193376/1982, but this method uses silver salt in the treatment solution, which is expensive and cannot be carried out in a short time. This is not desirable. Furthermore, Japanese Patent Publication No. 45-27690 describes a method for producing a black matte coating on the surface of a metal object. The method involves a first stage treatment in which the surface of the metal object is contacted with an acidic aqueous solution of a trivalent antimony salt to deposit a black antimony deposit, followed by a second stage treatment in which a phosphate protective coating is deposited thereon. However, since the blackness of the film is not sufficient in this first stage treatment and the film is uneven, it is not possible to obtain a good black film even after the second stage treatment, making it impractical. [Problems to be Solved by the Invention] The present invention is an improved antimony-containing acidic aqueous solution that can be processed in a short time and is inexpensive. The object of the present invention is to provide a blackening treatment solution and method for obtaining a film. [Means for Solving the Problems] The blackening treatment solution that achieves the object of the present invention contains antimony ions a of 0.2 to 5.0 g/l and metal ions b consisting of nickel ions, iron ions, and cobalt ions. It contains 10 to 100 g/l of one or more selected types, and the molar ratio of the metal ion b/the antimony ion a is 5 to 100 g/l.
110 is preferably 25 to 70, and is an aqueous solution with a pH of 6 or less. If fluoride ions are added to this aqueous solution, a uniform black film can be formed in a shorter time. Antimony ions are derived from soluble salts such as antimony potassium tartrate, antimony trichloride, and antimony pentachloride, and their concentration is 0.2 to 5.0 g/l.
used in If it is less than 0.2 g/l, it is insufficient to form a black film in a short time, and if it exceeds 5.0 g/l, the adhesion of the black film formed will be poor, which is not preferred. Nickel, iron, and cobalt metal ions include nickel carbonate, nickel nitrate, nickel chloride, nickel oxide, nickel sulfate, ferrous nitrate, and ferric nitrate.
Inorganic salts such as iron, ferrous chloride, ferric chloride, ferrous sulfate, ferric sulfate, cobalt carbonate, cobalt chloride, cobalt nitrate, cobalt sulfate, nickel acetate, ferric ammonium citric acid, cobalt acetate, etc. derived from organic compounds. In order to obtain a film with a high degree of blackness, the concentration of metal ions should be 10 to 10%.
100g/l, preferably 18g/l or more is required,
Further, the metal ion/antimony ion molar ratio is in the range of 5 to 110, preferably 25 to 70. Considering economic aspects, the upper limit of the metal ion concentration should be below 100 g/l, preferably below 50 g/l. Among the metal ions of nickel, iron, and cobalt, nickel ions are most preferred from the viewpoint of film reactivity. The fluoride ion is derived from hydrofluoric acid, hydrosilicic acid, hydroborofluoric acid, etc., and is used at a concentration of 1 to 60 g/l, preferably 3 to 60 g/l.
It is 30g/l. If it is less than 1 g/l, the uniformity of the film will be poor, and if it exceeds 60 g/l, the adhesion of the black film formed will deteriorate, and equipment will be severely corroded and the working environment will be poor. The pH of the blackening treatment liquid may be adjusted using an inorganic acid such as hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, hydrofluoric acid, or fluoroboric acid, or an organic acid such as acetic acid. A complexing agent such as tartaric acid, citric acid, malic acid, oxalic acid, succinic acid or salts thereof may be added to the blackening treatment liquid in order to stabilize the treatment liquid and prevent sludge from adhering to the object to be treated. I can do it. The amount of the complexing agent to be added is 0.1 to 40 g/l, taking into account the effects and economy of addition. The blackening treatment liquid of the present invention utilizes a substitution reaction between zinc of the material to be treated and antimony, nickel, iron, and cobalt, and is greatly influenced by treatment time and liquid temperature. The higher the liquid temperature, the faster the reaction rate, so it is preferably room temperature or higher. In particular, if a strip-plated steel plate is treated continuously, the treatment time will be 10 seconds or less, so in that case it is preferably 30°C or higher. The upper limit of the liquid temperature is preferably 80° C. or lower in consideration of moisture evaporation, safety, energy saving, etc. The black film formed by the blackening treatment liquid of the present invention has insufficient corrosion resistance and adhesion. In order to improve this corrosion resistance and adhesion, a chromate film, a phosphate film, an alkali silicate film, or a resin film is applied after the blackening treatment and washing with water. If a phosphate film is applied after blackening treatment, the degree of blackness will increase. The improvement in fingerprint resistance can be achieved by applying a resin film or a film containing an alkali silicate as a main component to the surface of the film. The resin film in the present invention is a known film formed by treatment with an aqueous solution of a water-soluble, emulsion-type or dispersion-type organic polymer resin, such as the film disclosed in Japanese Patent Publication No. 60-33192. Examples of such resins include currently used vinyl-based resins such as vinyl acetate, vinyl chloride, and vinylidene chloride, as well as their copolymers, acrylic acid, methacrylic acid, acrylic esters, methacrylic esters, and hydroxyacrylic acid. , acrylic systems such as hydroxyacrylic acid esters and their copolymers, alkyd systems, epoxy systems, urea systems, fluorine systems, urethane systems, ester systems, styrene systems, olefin systems and their copolymers,
Examples include resins such as synthetic rubbers such as butadiene and natural polymers. An inorganic substance such as a chromium compound or silica can be added to this organic polymer resin aqueous liquid as necessary. The chromate film is, for example, a film disclosed in JP-A-50-28444 and JP-A-60-218483, and is preferably formed using a partially reduced chromic acid aqueous solution. Alternatively, resin or silica particles (silica sol, fumed silica) having a size of several tens to several thousand angstroms may be contained. The weight ratio of Cr ³⁺ /Cr ⁶⁺ in the chromic acid aqueous solution is reduced to 1/1 by reducing it with an organic or inorganic reducing agent such as sugar or alcohol.
The pH of the aqueous solution should preferably be ~1/3, and the pH of the aqueous solution should be in the range of 1.5 to 4.0. If the amount of chromate film is too large, the black film will be hidden and the blackness will be weakened, and if it is too small, the effect of the chromate film will be weakened.
Film amount: 1 to 1000 mg/m ² , preferably 10 to 1000 mg/m 2
200mg/ ^m2 . For example, a film containing an alkali silicate as a main component is disclosed in Japanese Patent Publication No. 57-2274,
It can be obtained by treatment with an aqueous solution containing an alkali silicate as a main component represented by the general formula M ₂ O, nSiO ₂ (M: Na, K, Li, ammonium or amine, n: 2-20). , If necessary, a chromium compound such as chromic acid is further added to this. The amount of the alkali silicate film is set to 0.01 to 3 μm for the same reason as the chromate film. The phosphate film has a pH of 2.5 to 5, and contains zinc monophosphate, calcium zinc phosphate, aluminum phosphate, manganese monophosphate, sodium monophosphate, ammonium monophosphate, etc. as the main components. A phosphate aqueous solution is used, but a zinc phosphate aqueous solution is preferred in order to form a strong film with the best adhesion. For example, the phosphate aqueous solution described in Japanese Patent Publication No. 42-12130 is used. In the present invention, the first stage black film and the second stage black film are used.
A corrosion-resistant film is formed by the step chromate film, phosphate film, alkali silicate film, or resin film, but a third stage treatment is added, that is, black film → paint-on chromate film → resin film or By applying an alkali silicate film, black film → phosphate film → resin film → coated chromate film, or alkali silicate film on the surface of zinc or zinc alloy, a film with even better corrosion resistance can be obtained. One example of the treatment steps of the blackening treatment method of the present invention is:
It is as follows. (Degreasing → Water washing) → 1st stage treatment →
Water washing → [Surface conditioning with titanium colloid aqueous solution]
→ 2nd stage treatment → washing with water → [3rd stage treatment] → drying Here, the steps in [ ] are performed as necessary. The first, second, and third stage treatment conditions range from room temperature to
Treated at 90°C for any length of time by spraying, dipping, roll coating, etc. In addition to the above, known treatment aqueous solutions such as tannic acid aqueous solution and phytic acid aqueous solution may be used in the second and third stage treatments. [Operation] When zinc or zinc alloy is brought into contact with the blackening treatment solution of the present invention, Sb, Ni, Co, and Fe ions in the treatment solution are transferred to the surface of zinc or zinc alloy through a substitution reaction with Zn of the material. Depart. However, during the reaction, Sb and
Due to the difference in standard electrode potential between Ni, Co, or Fe and Zn, the precipitation and dissolution reactions proceed selectively and stepwise. That is, Sb, Ni (or Co, Fe), and Zn are easily precipitated in this order, and Zn, Ni (or Co, Fe), and Sb are easily dissolved in that order. The substitution reaction does not result in the precipitation of only Sb or the dissolution of only Zn, but rather the precipitation of Sb, Ni (or
Metals such as Co, Fe), and Zn repeatedly precipitate and dissolve, resulting in a film with a structure that absorbs light. When setting the conditions for the blackening treatment solution, the whiteness [W (Lab)] of the film was measured using a color computer manufactured by Suga Test Instruments Co., Ltd., as a measure of the degree of blackness. The whiteness is W (Lab) = 100−
[(100-L) ² +a ² +b ² ] It is expressed as ^1/2 , and the smaller the W value, the closer to black it becomes. The liquid temperature was 50℃ with various Sb ³⁺ concentrations.
Figure 1 shows the whiteness of the film formed by immersing a galvanized steel sheet with a zinc coating of 20 g/m ² in an acidic hydrochloric acid solution containing 15 g/l of Ni ²⁺ ^and 2-4 g/l of SiF ₆ for 10 seconds. . As can be seen from this figure, an Sb ³⁺ concentration of 0.2 g/l or more, preferably 1.3 g/l or more is required to obtain a black film. At a liquid temperature of 50℃ with various Co ²⁺ concentrations
A galvanized steel sheet with a zinc coating of ²⁰ g/m ² was treated with an acidic aqueous solution of hydrochloric acid containing 1.5 g/l of Sb ³⁺ and 2-4 g/l of SiF ₆ .
Figure 2 shows the whiteness of the film formed by the second spray treatment. As can be seen from this figure, in order to obtain a black film, the Co ²⁺ concentration must be at least 10 g/l, preferably
It turns out that 18g/l or more is required. Also Ni ²⁺ ,
Fe ³⁺ also shows almost the same value as Co ²⁺ . Sb ³⁺ 1.5g/l at 50°C with various pH changes,
In an aqueous solution containing Fe ³⁺ 20g/l, the amount of zinc deposited is 20g/l.
Figure ³ shows the whiteness of the film formed by spraying a 5-second galvanized steel sheet. From this figure, it can be seen that in order to obtain a black film, it is best to keep the pH of the treated aqueous solution at 6 or less. A zinc coating of 20 g/m ² was prepared using a hydrochloric acid aqueous solution containing ^2-4 g/l of SiF ₆ at a temperature of 50°C with various concentrations of Sb ³⁺ and Ni ²⁺ , Co ²⁺ , and Fe ³⁺ . Figure 4 shows the relationship between the molar ratio of Ni ²⁺ and Sb ³⁺ in the treatment solution to the whiteness of the film formed by spraying a galvanized steel sheet for 5 seconds, and the molar ratio of Co ²⁺ and Sb ³⁺ Figure 5 shows the relationship between , and Figure 6 shows the relationship between the molar ratio of Fe ³⁺ and Sb ³⁺ .
This is shown graphically in the figure. From these figures, it can be seen that metal ions of Ni ²⁺ , Co ²⁺ or Fe ³⁺ / Sb ³⁺ in the treated aqueous solution
It has been found that a molar ratio of 5 to 110, preferably 25 to 70, is suitable for obtaining a black film. [Example 1] Electrogalvanized steel sheet, containing 4 g/l of mantimonyl potassium tartrate in terms of Sb and 10 g/l of cobalt acetate in terms of Co, and having a pH of 1.5 and 50 to
Dip in an acidic solution of hydrochloric acid heated to 60℃ for 10 seconds to form a black film, wash with water, and then soak at 55-65℃.
Immersed in an aqueous solution (Bonderite 3300, manufactured by Nippon Parkerizing Co., Ltd.) mainly composed of zinc phosphate for zinc with a total acidity of 20 points for 10 seconds, washed with water, dried, and subjected to appearance evaluation and film adhesion testing. The results are shown in Table 1. [Example 2] Electrolytic galvanized steel sheet was coated with antimony trichloride.
0.5g/l in terms of Sb and ferrous sulfate in terms of Fe.
25g/l, and had a pH of 1.3 and was heated to 55-65°C, immersed for 7 seconds to form a black film, washed with water, and then heated to 55-65°C. It was immersed in an aqueous solution (Bonderite 3300, manufactured by Nippon Parkerizing Co., Ltd.) mainly composed of zinc phosphate with a total acidity of 25 points for 7 seconds, then rinsed with water, and then soaked in a 0.1 g/l chromic acid aqueous solution at 60 to 70°C. Table 1 shows the results of immersion for 3 seconds, draining, drying, appearance evaluation and film adhesion test. [Example 3] Electrolytic galvanized steel sheets and alloyed hot-dip galvanized steel sheets were treated with antimonyl potassium tartrate of 1.5 g/l in terms of SB and nickel chloride of 30 g/l in terms of Ni.
and a hydrochloric acid aqueous solution containing 10 g/l of silicic acid in terms of F and having a pH of 1.5 and heated to 60 to 70°C for 5 seconds (for electrogalvanized steel sheets) to 10 seconds (for alloys). (For hot-dip galvanized steel sheets) Dip to form a black film, wash with water, and then heat to 60 to 70°C in an aqueous solution containing zinc phosphate as the main component (Bonderite 3300) with a total acidity of 15 points. (manufactured by Nippon Parkerizing Co., Ltd.) for 10 seconds and rinsed with water.
Table 1 shows the results of drying, appearance evaluation and adhesion test. [Comparative Example 1] An electrogalvanized steel sheet containing 1 g/l of mantimonyl potassium tartrate in terms of Sb and a pH of 1.5.
Dip for 10 seconds in an acidic solution of hydrochloric acid heated to 50 to 60℃ to form a black film, wash with water, and then
An aqueous solution mainly composed of zinc phosphate for zinc with a total acidity of 20 points (Bonderite
3300. (manufactured by Nippon Parkerizing Co., Ltd.) for 10 seconds, washed with water, dried, and subjected to appearance evaluation and adhesion test. Table 1 shows the results. [Comparative Example 2] Only the first stage treatment of Example 1 was performed, the results were washed with water, dried, and subjected to appearance judgment and adhesion test.
Shown in the table. [Table] [Example 4] Adding antimonyl potassium tartrate to aqueous hydrochloric acid solution
3g/l in terms of Sb and nickel nitrate in terms of Ni.
30 g/l and 5 g/l of silicic acid in terms of F, the Ni ²⁺ /Sb ³⁺ molar ratio of the aqueous solution was 21, and the PH was
Prepare a bath with the blackening treatment solution adjusted to 1.7, and heat it to 50-55℃.
It was heated to A galvanized steel sheet was immersed in this treatment solution for 10 seconds to form a black film, washed with water, and dried. [Example 5] A galvanized steel sheet was subjected to the treatment of Example 4 except for the drying step, and then the solid content concentration was 20 g/l,
A coated chromate treatment aqueous solution with a weight ratio of Cr ³⁺ /Cr ⁶⁺ of 2/3 and pH adjusted to 2.5 with KOH was applied, and dried after roll pass. [Example 6] A galvanized steel sheet was treated as in Example 4 except for the drying step, and then an aqueous acrylic resin solution (Watersol S744, manufactured by Dainippon Ink Co., Ltd.) was applied and dried to a dry film thickness of 1 μm. . [Example 7] A galvanized steel sheet was subjected to the treatment of Example 4 except for the drying process, and then lithium silicate (Li ₂ O ₄ ,
8SiO ₂ ) aqueous solution was applied using a roll coater and dried. [Example 8] A galvanized steel sheet was subjected to the treatment of Example 4 excluding the drying step, and then heated to 60 to 65 ° C. A phosphate film treatment aqueous solution (Bonderite 3300 (manufactured by Nippon Parkerizing Co., Ltd.) for 10 seconds, washed with water, and dried. [Example 9] After applying the treatment of Example 5 to a galvanized steel sheet, coating with the acrylic resin aqueous solution of Example 6,
I did drying. [Example 10] A galvanized steel sheet was subjected to the treatment of Example 5, and then coated with the lithium silicate aqueous solution of Example 7 and dried. [Example 11] A galvanized steel sheet was subjected to the treatment of Example 8 except for drying, and then coated with the aqueous acrylic resin solution of Example 6 and dried. [Example 12] A galvanized steel sheet was subjected to the treatment of Example 8 except for drying, and then coated with the coating type chromate treatment aqueous solution of Example 5 and dried. [Example 13] A galvanized steel sheet was subjected to the treatment of Example 8 except for drying, and then coated with the lithium silicate aqueous solution of Example 7 and dried. [Comparative Example 3] A galvanized steel sheet was treated in the same manner as in Example 4, except that the blackening treatment liquid did not contain nickel nitrate. [Comparative Example 4] Concentration of nickel nitrate in blackening treatment solution in terms of Ni
A galvanized steel sheet was treated in the same manner as in Example 4, except that the Ni ²⁺ /Sb ³⁺ molar ratio was 5 g/l and 10. [Comparative Example 5] Mantimonyl potassium tartrate in the blackening treatment solution was
1g/l in terms of Sb, 60g/l in terms of Ni nitrate
A galvanized steel sheet was treated in the same manner as in Example 4, except that the Ni ²⁺ /Sb ³⁺ molar ratio was 120. [Comparative Example 6] Mantimonyl potassium tartrate in the blackening treatment solution was
4.6g/l in terms of Sb, nickel nitrate in terms of Ni
A galvanized steel sheet was treated in the same manner as in Example 4, except that the Ni ²⁺ /Sb ³⁺ molar ratio was 10 g/l and 4.5. Examples 4, 5, 6, 7, 8, 9, 10, 11,
Regarding the galvanized steel sheets treated in Comparative Examples 12, 13 and Comparative Examples 3, 4, 5, and 6, the results of the fingerprint resistance test are shown in Table 2, and the results of the film adhesion test are shown in Table 3. Table 4 shows the results of the whiteness measurement, and FIG. 7 shows the results of the salt spray test. [Table] [Table] [Table] [Table] [Table] [Effects of the invention] The present invention can form a black film on the surface of zinc or zinc alloy in a short time, and does not use silver salt in the treatment solution. Therefore, it can be constructed at a lower cost than the conventional black chromate method. Also, special public service in 1977-
The method for forming a black matte coating described in Japanese Patent No. 27690 also allows a black and uniform coating to be formed on the surface of zinc or zinc alloy. Moreover, since a chromate film, phosphate film, alkali silicate film, or resin film is further applied on the black film, it is also excellent in terms of fingerprint resistance, film adhesion, and corrosion resistance.