JPH05171489A - Liquid composition for plating - Google Patents

Abstract

PURPOSE:To provide a liq. composition for plating without need to heat a bath to a high temp., without need for a high-temp. jet, capable of obtaining a high current density under the easily controllable bath conditions in low-speed agitation at the low temp. of 30 deg.C bath temp., for example, and suitable for high-speed (short time) plating in an acidic or weakly acidic plating bath. CONSTITUTION:This acidic or weakly acidic liq. composition consists essentially of a metal ion, a conductive acid or its salt and a nonionic surfactant or an ionic surfactant having a polyalkylene group, and at least one kind of phenanthroline compd. is incorporated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition liquid for plating, and more specifically, a composition liquid for plating (hereinafter referred to as "high speed plating" by those skilled in the art. Plating bath or simply referred to as a plating solution).

[0002]

2. Description of the Related Art Recently, in a plating factory, continuous plating treatment of an object to be plated (plating material) has been desired in order to improve productivity, and high-speed plating is partially performed. For high-speed plating, it is necessary to apply a large current to the plating bath so that the bath has a high current density. In conventional high-speed plating, for example, tin plating for obtaining a tin steel plate, a high-speed jet is applied to the plating bath to make the plating bath in a fluid state and a large current is applied to the bath.

Further, as a conventional technique for plating at a high current density, (a) a nonionic surfactant, a cationic surfactant, a heterocyclic compound (or a derivative thereof such as 8-oxyquinoline), and 1,4- or 1,7
-A solder plating bath containing dihydroxynaphthalene and having a high current density of 110 A / dm ² (Japanese Patent Laid-Open No. 1-96
(391, JP-A-1-96392, JP-A-1-56490), (b) α-naphtholsulfonic acid ethylene oxide adduct and polyoxyalkylene cumylphenol as stable and low foaming components at high bath temperature. Using ether (both surfactants), current density 100A / dm ²
Solder plating baths that can be used up to a certain degree (JP-A-3-94093 and JP-A-3-94094), (c) Alkylpyridinium salt and unsaturated carbonyl compound are included, and high temperature of 50 ° C or more and about 3 m / sec. Current density of 100 due to the high-speed jet flow of
A tin plating bath (Japanese Patent Publication No. 1-20240) corresponding to A / dm ² is known.

[0004]

However, the above-mentioned conventional plating bath for high-speed plating has a high-speed jet (10 to 10).
High-speed plating at a high current density cannot be achieved unless the liquid flow control is performed by applying 30 m / sec), and the liquid flow control for obtaining a stable plating film is difficult and requires skill. Further, it is disclosed that the plating bath of the prior art (a) mentioned above contains 1,4- or 1,7-dihydroxynaphthalene to cope with a high current density up to 110 A / dm ² , but it is an essential component. Since nitrogen-containing heterocyclic compounds such as 8-oxyquinoline used as are expensive and carcinogenic, they are difficult to carry out. Further, the plating baths of the prior arts (b) and (c) must be a high-speed jet stream at high temperature, which makes it difficult to manage the bath.

The object of the present invention has been made in view of the above-mentioned conventional problems. Needless to say, the drug used is inexpensive and has no carcinogenicity, and it is not necessary to raise the bath temperature to a high temperature. And it does not require a high-speed jet, for example, room temperature 30 ° C
Under easy-to-manage bath conditions in low-temperature low-speed stirring of
It is an object of the present invention to provide a plating composition liquid which can obtain a high current density and is suitable for high speed (short time) plating of an acidic plating bath or a weakly acidic plating bath.

[0006]

Means for Solving the Problems In the study of high speed plating, the present inventor has selected a metal ion and a conductive acid or a salt thereof, and a nonionic surfactant or an ionic surfactant having a polyoxyalkylene group. Including the plating bath composition,
As a result of an experiment, they have found that high-speed plating with extremely high current density tolerance is possible when a phenanthroline-based compound is contained, and the present invention has been achieved.

That is, the invention for achieving the above-mentioned object includes a metal ion, a conductive acid or a salt thereof, and a nonionic surfactant or an ionic surfactant having a polyoxyalkylene group. It is characterized in that it is based on an acidic or weakly acidic composition liquid and contains at least one phenanthroline compound.

Plating using the above-mentioned acidic or weakly acidic composition liquid is mainly for tin plating and solder (tin-plating).
Lead alloy) plating and zinc plating. These platings can be applied as bright plating or dull or semi-bright plating.

The composition of the plating solution for tin plating or solder plating is basically a divalent tin salt, stannous sulfate,
Stannous chloride, stannous borofluoride, stannous alkanol sulfonate, or stannous methane sulfonate, stannous phenol sulfonate, stannous cresol sulfonate, stannous acetate, and the like, and Examples of the lead salt include lead chloride, lead borofluoride, lead alkanol sulfonate, lead methane sulfonate, lead phenol sulfonate, lead cresol sulfonate, lead acetate, lead oxide and the like. Then, as the conductive acid or salt, sulfuric acid, hydrochloric acid, borofluoric acid, acetic acid, alkanol sulfonic acid, methane sulfonic acid, phenol sulfonic acid, cresol sulfonic acid, citric acid, malic acid, tartaric acid, boric acid, etc. One or more selected from acids and their ammonium salts, sodium salts, potassium salts and the like can be used.

The composition of the plating solution for zinc plating is
Examples of the zinc salt include zinc chloride, zinc sulfate, zinc acetate, zinc carbonate, zinc oxide, and the like, and conductive acids or salts include acids such as hydrochloric acid, sulfuric acid, acetic acid, and boric acid, and their ammonium salts, sodium. One kind or two or more kinds selected from salt, potassium salt and the like can be used.

The nonionic or ionic surfactant is contained in the plating bath at a concentration of 0.5 to 40 g / L.

Examples of the nonionic surfactant include polyoxyalkylene alkylphenol ether, polyoxyalkylene higher alcohol ether, polyoxyalkylene-α- or β-naphthol ether, polyoxyalkylene-mono-, di- or tri-styrene. Phenol ethers, polyoxyethylene-polyoxypropylene block polymers, polyoxyethylene-polyoxypropylene condensates of ethinonediamine, polyoxyalkylene-added alkylamines, polyoxyalkylene-added alkylamides and the like are used.

Examples of the ionic surfactant having a polyoxyalkylene group include anionic surfactants such as alkylphenoxypolyoxyalkyleneethylsulfonic acid and its salts, higher alcohol polyoxyalkyleneethylsulfonic acid and its salts, and the like. A cationic surfactant such as N, N-dipolyoxyalkylene-N, N-dialkylammonium hydrochloride is used.

In the plating bath, other cationic surfactants, amphoteric surfactants such as N-monoalkyl-N-trimethylammonium salt, N, N-dialkyl-N-dimethylammonium salt, Cationic surfactants such as N-alkyl-isoquinolinium salts, 1-alkyl-1-hydroxyethyl-imidazolium salts, 1-hydroxyethyl-1-carboxyalkylene-2-alkylimidazolium betaines, N, N-dimethyl- N-
An amphoteric surfactant such as alkyl betaine can be added if necessary. The surfactant is used in a total bath concentration of 0.5 to 40 g / L, and a desirable concentration is 1 to 30 g / L.

Although not necessary for zinc plating, tin plating,
In solder plating, it is preferable to use an antioxidant such as catechol or hydroquinone together in order to prevent oxidation of tin (Sn ²⁺ ). The concentration of these antioxidants in the bath is 0.05 to 20 g / L, and the desirable concentration range is 0.1 to
It is 15 g / L.

Bright plating in tin plating and solder plating is carried out by using aromatic carbonyl compounds such as benzaldehyde, o-chlorobenzaldehyde, tolualdehyde, anisaldehyde, cinnamaldehyde, 2,5-dimethoxybenzaldehyde, as a brightening component.
-Or 2-aromatic aldehydes such as naphthaldehyde,
Aromatic ketones such as benzylideneacetone and alkyl naphthyl ketones are used. Also, as an auxiliary brightener component,
Aliphatic aldehydes such as formaldehyde and acetaldehyde, o-, m- or p-aminophenol, aromatic amines such as sulfanilic acid and the like can be used.
These gloss imparting components and auxiliary brightener components may be used alone or in combination of two or more, and may be used in any combination as required.

Also in galvanization, if necessary, as auxiliary brightening agents, aliphatic amines such as polyethyleneimine, amines such as epihalohydrin reaction products of aliphatic amines, and aromatic carboxylic acid compounds such as benzoic acid salts (ammonium, Potassium or sodium salt), chloro-substituted benzoic acid salt (ammonium, potassium or sodium salt) and the like can be used.

The gloss imparting component and the auxiliary glossing agent component are 0.005 to 5 g / L in the bath in the gloss imparting component,
The desirable concentration is 0.01 to 2 g / L, the auxiliary brightener component is 0.01 to 30 g / L in the bath, and the desirable concentration is 0.05 to 15 g / L.

The phenanthroline compound is 1,1
0-phenanthroline, 2,9-dimethylphenanthroline, 3,4,7,8-tetramethylphenanthroline, 4,7-dihydroxyphenanthroline, 4,7-
Diphenyl-1,10-phenanthroline (basophenanthroline), 4,7-diphenyl-2,9-dimethylphenanthroline (basocuproine), 4,7-diphenyl-1,10-phenanthroline-disulfonic acid and its salts (basophenanthroline disulfonic acid) And its salts), 4,7-diphenyl-2,9-dimethyl-1,1
0-phenanthroline-disulfonic acid and its salt (basocuproine disulfonic acid and its salt) and the like are used.

The phenanthroline compound can be used alone or in combination of at least one kind selected from the compounds exemplified above. The concentration of the phenanthroline compound in the plating bath is 0.0001 to 10 g /
L, and preferably 0.001 to 1 g / L. If the amount of the phenanthroline compound is less than 0.0001 g / L, the high current density durability cannot be obtained in the plating bath, and if it exceeds 10 g / L, the electrodeposition of the plating film is extremely suppressed and a predetermined film thickness is obtained. Absent.

As can be seen from the above-mentioned use concentration, the characteristics of the phenanthroline-based compound are slightly different depending on the structure of the compound, but the addition of a very small amount is generally effective, and in the matte or semi-glossy bath, several ppm. To several tens of ppm.
It is possible to carry out plating of about 100 A / dm ^{2 by} using the order, even at insufficient room temperature and under an insufficient agitation condition, and a truly surprising effect is exhibited. Further, the phenanthroline compound can be used in a gloss bath, and it is necessary to increase the addition amount to some extent due to the influence of the gloss-imparting component and the auxiliary gloss agent, but again, several ppm. Even if the concentration is about several g / L, a strong effect of enhancing the high current density portion can be obtained, and the concentration of the gloss-imparting component used can be greatly reduced, which is extremely useful.

[0022]

In the present invention, the nonionic and ionic surfactants serve to improve and control the deposition of the plating film. The phenanthroline-based compound has an action capable of achieving a high current density in a low stirring or non-stirring bath at low temperature such as normal temperature.

[0023]

EXAMPLES Next, examples of the present invention will be described. (Example 1) Bright plating of tin was performed on an object to be plated under the plating bath shown in Table 1 and the following plating condition A.

[0024]

Plating condition A Cathode current density: 5, 10, 30, 60, 100A
There are 5 levels of / dm ² . Plating time at each stage: current density × time = 10 Amin.
It was set to be / dm ² . Positive electrode: Platinum-plated titanium plate Bath temperature: 30 ° C Stirring: Mild stirrer stirring Substrate: Approximately 2 μm copper-plated steel plate The results of plating at each stage of current density are shown in Table 2. there were.

[0026]

The film thickness was measured by a fluorescent X-ray micro film thickness meter. As is clear from Table 2, in Example 1, 5 to 1
In a wide current density range of 00 A / dm ² , an excellent gloss appearance was obtained and a sufficient film thickness was obtained.

Comparative Example 1 Using the plating bath having a liquid composition obtained by removing 1,10-phenanthroline from the composition components of the plating bath in Table 1, plating was carried out under the same conditions and the same method as in Example 1.

[0029]

As is clear from Table 3, in the liquid composition excluding 1,10-phenanthroline, the film thickness of the plating film was reduced at 30 A / dm ² or more.

(Example 2) Semi-gloss plating of solder was carried out on the object to be plated under the plating bath shown in Table 4 and the following plating condition B.

[0032]

Plating Condition B Cathode Current Density: 5, 10, 30, 50, 70, 1
It was set to 6 stages of 00 A / dm ² . Plating time at each stage: current density × time = 10 Amin.
It was set to be / dm ² . Positive electrode: Platinum-plated titanium plate Bath temperature: 30 ° C Stirring: Slow stirring with stirrer Substrate: Approximately 2 μm nickel-plated phosphor bronze plate The results of plating at each stage of current density are shown in Table 5. It was as shown.

[0034] The film thickness and alloy ratio were measured with a fluorescent X-ray micro film thickness meter.

As is clear from Table 5, in Example 2, 5
In a wide current density range of up to 100 A / dm ² , a uniform and dense semi-glossy plating film is obtained, and it deposits with extremely stable current efficiency even though the plating bath is not sufficiently stirred. Was recognized. Then, in Example 2, the correlation between the metal composition ratio in the plating bath and the metal composition ratio in the deposited film was also good. The plating bath composition of Example 2 had extremely low foaming in the above wide current density.

Comparative Example 2 A plating bath having a liquid composition obtained by removing 2,9-dimethyl-1,10-phenanthroline from the composition components of the plating bath shown in Table 4 was used under the same conditions and method as in Example 2. Plating was performed. The results of this plating are shown in Table 6.

[0037]

As is clear from Table 6, in the liquid composition excluding 2,9-dimethyl-1,10-phenanthroline,
Abnormal deposition (gray deposition to black deposition) of the plating film at 30 A / dm ² or more, and with this, a sharp decrease in film thickness and lead eutectoid ratio occurred.

Example 3 In the plating bath composition of Example 2 (Table 4), 0.01 g / L of 2,9-dimethyl-1,10-phenanthroline was added to 3,4,7,8-tetramethylphenanthroline. Using the plating bath replaced with 0.05 g / L of the above, the semi-gloss plating of solder was performed on the object to be plated under the same conditions and methods as in Example 2. The results of this plating are shown in Table 7.

[0040]

The third embodiment is 5 to 100 in the same manner as the second embodiment.
It was confirmed that a uniform and dense semi-glossy plating film was obtained at a wide current density of A / dm ² , and the correlation between the metal composition ratio in the bath and the metal composition ratio of the deposited film was good.

(Example 4) Bright plating of zinc was performed on the object to be plated under the plating bath shown in Table 8 and the following plating condition C.

[0043]

Plating condition C Cathode current density: 5, 10, 20, 30 A / dm ²
There are four levels. Plating time of each step: current density × time = 20 Amin.
It was set to be / dm ² . Positive electrode: Zinc plate (purity 99.99%) Bath temperature: 35 ° C. Stirrer: Mild stirrer stirring Substrate: Rolled steel plate The results of plating at each stage of current density are shown in Table 9. It was

[0045]

As is clear from Table 9, in Example 4, 5
A wide current density range of ~30A / dm ^2, with resulting excellent gloss appearance, sufficient film thickness is obtained.

Comparative Example 3 Using the plating bath composition of Example 4 (Table 8) except for bathophenanthroline, plating was performed under the same conditions and method as in Example 4. The results of this plating are shown in Table 10.

[0048]

As is clear from Table 10, the liquid composition of Example 4 excluding bathophenanthroline caused a gray matte deposition to a kogation-like black deposition and a decrease in film thickness at 20 A / dm ² or more. occured.

As is clear from the above Examples 1 to 4 and Comparative Examples 1 to 3, 1,10-phenanthroline,
2,9-dimethyl-1,10-phenanthroline, 3,
The plating bath containing 4,7,8-tetramethylphenanthroline and bathophenanthroline was 100 A / dm ^{2 in} spite of gentle stirring at a bath temperature of 30 ° C.
It is recognized that high current densities of 10 are easily obtained. Further, in the plating baths of Examples 1 to 4, it was possible to carry out plating with a sufficient film thickness in a wide current density range.

Next, in each of the plating baths of Examples 1 to 4, high-speed plating of tin, solder, and zinc was performed in a plating tank of a factory with a low-speed jet flow (5 m / min) at a bath temperature of 35 ° C.,
In all cases, it was possible to obtain a uniform plating film without burning or fogging. This is because in the conventional plating bath, due to the limitation on the high current density side, the current efficiency is lowered and abnormal deposition such as kogation or fog occurs in extreme cases, whereas Examples 1 to 4
Since the formation of hydroxide of the metal ions on the cathode surface is suppressed in the plating bath, the plating bath can be plated on a substrate having high current efficiency. Moreover, Examples 1 to 1
According to another test using each plating bath of 4, the bath temperature is 30 ℃
Even if the plating bath is hardly stirred at 100
Plating was possible with a high current of about A / dm ² .

[0052]

EFFECTS OF THE INVENTION Since the present invention is a plating bath containing a phenanthroline compound, a high current density can be obtained under a bath condition that is easy to control, such as low temperature stirring at a low bath temperature of 30 ° C. or no stirring. can get. Further, the present invention is suitable for high-speed (short-time) plating of tin, solder, zinc or the like because it can easily obtain a high current density and is an acidic plating bath or a weakly acidic plating bath. Also,
The phenanthroline compound in the present invention is inexpensive, unlike, for example, conventional 8-oxyquinoline,
And it is convenient because it is a carcinogen-free drug.

Claims (1)

[Claims] 1. A basic or acidic composition liquid containing a metal ion, a conductive acid or a salt thereof, and a nonionic surfactant or an ionic surfactant having a polyoxyalkylene group. And a plating composition liquid containing at least one phenanthroline compound.