JPH0245720B2 - - Google Patents

Description

Detailed Description of the Invention <Industrial Application Field> The present invention relates to a black electroplating bath using nickel and nickel alloys, and more specifically, nickel salt solution or nickel and cobalt, iron, tin, manganese, molybdenum, copper, By adding additives to a mixed solution of one or more selected from zinc, etc., it is possible to obtain a glossy black plating with excellent corrosion resistance and discoloration resistance. It is applied to plating solar heat absorbing materials with low emissivity (ε).

<Prior art> Conventionally, this type of black plating bath includes, for example, a black chromium plating bath, a black nickel plating bath containing thiocyanic acid, and nickel, nickel-tin, and nickel plating baths containing sulfur-containing amino acids as additives. - Various black plating baths for zinc are known.

<Problems to be Solved by the Invention> However, the conventional plating baths described above all have the following drawbacks.

That is, the black chromium plating bath has drawbacks such as requiring a low temperature, requiring a large current, and problems in wastewater treatment because hexavalent chromium is released in the wastewater.

Furthermore, black nickel plating baths containing thiocyanic acid use a large amount of sodium thiocyanide, a cyanide-based compound, and are therefore subject to total cyanide regulations under the Water Pollution Act, which is unfavorable from an environmental standpoint, and mechanically It has drawbacks such as poor strength and problems with corrosion resistance and discoloration resistance.

Furthermore, black plating baths containing sulfur-containing amino acids as additives have a serious drawback of the odor peculiar to sulfur-containing amino acids.

The present invention has been made in order to solve the problems of the prior art described above, and its purpose is to facilitate wastewater treatment without containing harmful substances such as hexavalent chromium and toxic substances such as cyanide, and to provide an odor-emitting solution. To provide a black electroplating bath made of nickel and nickel alloy, which is environmentally friendly without generating any oxidation, and has excellent corrosion resistance and discoloration resistance.

<Means for Solving the Problems> In order to solve the above problems, as a result of intensive research, the present inventors have discovered that a reaction product in which a quaternizing agent is applied to a polyalkylamine exhibits a strong tendency to blacken. The present invention has been accomplished.

That is, the present invention provides nickel as a metal or one or more metals selected from cobalt, iron, tin, manganese, molybdenum, copper, and zinc to be alloyed with nickel, and one of an amino acid or a salt thereof.
species or two or more species, a polyalkylamine selected from ethylenediamine, propylenediamine, butanediamine, diethylenetriamine, dipropylenetriamine, triethylenetetramine, and tetraethylenepentamine, and epihalohydrin,
1 selected from dichlorohydrin, monochloroacetic acid, monochloroethyl acetate, benzyl chloride, propane oxide, and ethylene chlorohydrin
It is characterized by containing a species or a reactant with two or more quaternizing agents.

Next, each composition constituting the black electroplating bath of the present invention and the suspending agent, buffering agent, reducing agent, PH adjuster, etc. added as necessary will be explained.

The anions of nickel salt include sulfuric acid, hydrochloric acid,
Acetic acid, sulfamic acid, citric acid, etc. can be used. Metal salts for alloying with nickel include cobalt, iron, tin, manganese, molybdenum, copper, zinc, etc., and one or more of these metals are added. The appropriate amount of nickel to be added is within the range of 6 g/-40 g/metal.

Also, as amino acids, common amino acids such as glycine, alanine, serine, aminobutyric acid, threonine, valine, norbatine, leucine, tyrosine, proline, aspartic acid, glutamic acid, lysine, ornithine are suitable, and these amino acids or their salts are suitable. One or more of these are used. The amount of amino acids added is 1g/~100
A range of g/ is appropriate.

In addition, polyalkylamines include ethylenediamine, propylenediamine, butanediamine,
Examples include diethylenetriamine, dipropylenetriamine, triethylenetetramine, and tetraethylenepentamine.

Examples of the quaternizing agent include epihalohydrin, dichlorohydrin, monochloroacetic acid, monochloroethyl acetate, benzyl chloride, propane oxide, and ethylene chlorohydrin.

Examples of the reaction product between the polyalkylamine and one or more quaternizing agents selected from the quaternizing agents include a reaction product obtained by reacting diethylenetriamine and epichlorohydrin in a 1:1 molar ratio, triethylene, etc. There is a reaction product in which tetramine and monochloroethyl acetate are reacted in a 1:2 mole ratio, and a reaction product in which tetraethylenepentamine is reacted with ethylene chlorohydrin and further dichlorohydrin in a 1:1:1 mole ratio. The appropriate concentration of this reactant is 0.1g/~100g/as amine, and
The pH is adjusted to be slightly acidic within the range of 3.0 to 8.5, preferably 4.5 to 6.5. In this case, sulfuric acid, hydrochloric acid, sulfamic acid, citric acid, gluconic acid, acidic sodium sulfite, etc. are used to lower the pH.
Alkali metals, ammonia, nickel hydroxide, etc. are used to increase the pH.

In addition, as a suspending agent, ammonium chloride,
Potassium chloride, sodium chloride, citric acid, gluconic acid, tartaric acid, etc. are used.

Further, as a buffering agent, boric acid, sodium acetate, etc. are used, and as a reducing agent, ascorbic acid, sodium sulfite, acidic sodium sulfite, etc. are used.

Nickel is used as the anode, but other insoluble anodes such as carbon and platinum can also be used. In the case of nickel and cobalt, metallic cobalt and alloys of nickel and cobalt can also be used. In the case of iron, it is iron or nickel.
Iron alloys can be used.

<Function> The reaction product of a polyalkylamine and a quaternizing agent shows a strong tendency to blacken, is particularly compatible with nickel, and becomes uniform in the presence of amino acids.

Therefore, pure nickel black plating or nickel alloy black plating can be obtained. A plating film with excellent corrosion resistance and discoloration resistance is obtained, and can be applied to various uses other than decoration, such as plating solar heat absorbing materials with low emissivity (ε).

Furthermore, unlike conventional black plating baths, it does not contain harmful substances such as hexavalent chromium or cyanide, and there is no bad odor.

<Example> Next, examples and comparative examples of the present invention will be described.

Example 1 Nickel chloride 60g/Ammonium chloride 30g/Glycine 20g/30% solution of diethylenetriamine and epichlorohydrin reacted in a 1:1 molar ratio 10ml/PH 4.5-6.5 Stirring None Temperature 45°C Hull cell with bright nickel plating When electrodeposition was carried out using a plate at 1 A/dm ² for 3 minutes in a Hull cell bath, a glossy black nickel film with excellent corrosion resistance and discoloration resistance was obtained on the entire surface.

Example 2 Nickel sulfate 40g/Cobalt sulfate 60g/Ammonium chloride 60g/L-sodium glutamate 20g/Boric acid 20g/30% aqueous solution of triethylenetetramine and monochloroethyl acetate reacted in a 1:2 molar ratio
20ml/PH 5.5 Temperature 40°C Electrodeposition using a Hullcel plate with bright nickel plating at 1A/dm ² for 3 minutes in a Hullcel bath resulted in a glossy black alloy with excellent corrosion resistance and discoloration resistance on all surfaces. A film was obtained.

Example 3 Nickel sulfate 40g / Ferrous sulfate 100g / Diammonium citrate 100g / Lysine 20g / Boric acid 20g / Reactant of Example 1 200ml / PH 5.0 Temperature 40°C A Hull cell plate with bright nickel plating was prepared. When electrodeposition was performed in a Hull cell bath at 1 A/dm ² for 3 minutes, a glossy black alloy film was obtained on the entire surface with excellent corrosion resistance and discoloration resistance.

Example 4 Nickel chloride 120g/Stannic chloride 3g/Citric acid 60g/Boric acid 20g/Glycine 20g/Tetraethylenepentamine was reacted with ethylene chlorohydrin and dichlorohydrin in a 1:1:1 mole ratio30 % aqueous solution 20ml/PH 6.0 Temperature 45°C Electrodeposition was performed in a Hullcel bath at 1A/dm ² for 3 minutes using a Hullcel plate with bright nickel plating, resulting in a beautiful black color with excellent corrosion resistance and discoloration resistance. A film was obtained.

Example 5 Nickel sulfate 60g / Manganese sulfate 3g / Ammonium chloride 30g / Sodium sulfite 3g / Sodium L glutamate 10g / Reactant of Example 2 20ml / PH 5.5 Temperature 40°C Using a Hull cell plate with bright nickel plating Electrodeposition was performed in a Hull cell bath at 1 A/dm ² for 3 minutes, and a glossy black nickel-manganese alloy plating film with excellent corrosion resistance and discoloration resistance was obtained.

Example 6 Nickel sulfate 80g / Zinc sulfate 10g / Ammonium sulfate 10g / Boric acid 20g / Glycine 20g / Sodium sulfite 5g / Reactant of Example 1 20ml / PH 5.7 Temperature 50°C Using a Hull cell plate with bright nickel plating When plating was applied at 1A/dm ² for 3 minutes,
A glossy black alloy plating film with excellent corrosion resistance and discoloration resistance was obtained.

Comparative Example 1 Nickel chloride 60g/ammonium chloride 30g/glycine 20g/PH 5.5 Temperature 45°C Plating was carried out at 1A/dm ² for 3 minutes using a Hullcell plate with bright nickel plating, but black was not obtained. Unable to do so, he became a hater.

Comparative Example 2 Nickel sulfate 120g / Nickel chloride 15g / Ammonium chloride 15g / Boric acid 20g / Methionine 20g / PH 5.3 Temperature 35℃ Plating at 1A/dm ² for 3 minutes using a Hullcel plate with bright nickel plating When I went to
Although some parts were black, most of them had many streaks and were not suitable for practical use.

From Examples 1 to 6 above, it was confirmed that pure nickel black plating or nickel alloy black plating could be obtained by adding a reaction product of polyalkylamine and quaternizing agent.

Comparative Example 1 was obtained by removing the reaction product of polyalkylamine and quaternizing agent from Example 1, and the other bath compositions were the same, but no black plating was obtained.

Similarly, in Comparative Example 2, since the reaction product of polyalkylamine and quaternizing agent was not added,
The black plating as in Examples 1 to 6 could not be obtained.

<Effects of the Invention> As explained above, according to the present invention, wastewater treatment is easy because it does not contain harmful substances such as hexavalent chromium and toxic substances such as cyanide, and it is environmentally friendly because it does not generate bad odors. ing.

In addition, according to the present invention, it is possible to obtain a black film made of pure nickel, and by alloying with one or more of cobalt, iron, tin, manganese, molybdenum, copper, and zinc, corrosion resistance and It can improve performance such as color fastness, and can be applied to various uses.

Claims (1)

[Claims] 1. Nickel as a metal or cobalt, iron, tin, manganese, molybdenum to be alloyed with nickel,
One or more metals selected from copper and zinc, one or more amino acids or salts thereof, and ethylenediamine, propylenediamine, butanediamine, diethylenetriamine, dipropylenetriamine, triethylenetetramine, and tetraethylene. Polyalkylamine selected from pentamine, epihalohydrin, dichlorohydrin,
A reactant with one or more quaternizing agents selected from monochloroacetic acid, monochloroethyl acetate, benzyl chloride, propane oxide, and ethylene chlorohydrin; Black electroplating bath.