JPS61163289A - Black electroplating bath by nickel and nickel alloy - Google Patents

Abstract

PURPOSE:To obtain the title black electroplating bath capable of obtaining a bright black plating having excellent corrosion resistance by composing the bath of an aq. soln. contg. nickel ions or the ions and alloy ions, amino acids, and amine-modified material, etc. CONSTITUTION:An aq. soln. for black electroplating by nickel and a nickel alloy is obtained by incorporating essentially a nickel salt and >=1 kind of metallic salt for alloying among iron, tin, manganese, molybdenum, copper, zinc, etc. and a nickel salt, amino acids, amine-modified materials, and adding, if necessary, a suspending agent, a buffer, a reducing agent, a pH regulating agent, etc. The sulfate, chlorate, acetate, etc. can be used as the salts of the nickel and alloy, glycine, etc. is used as the amino acid, and a modified material obtained by allowing a quaternary compd.-forming agent such as epihalohydrin to act on an amine such as polyalkylpolyamine is appropriately used as the amine-modified material.

Description

[Detailed Description of the Invention] <Industry - Field of Application> The present invention relates to an electroplating method, in which a nickel salt solution or a nickel gel selected from hycobalt, iron, tin, manganese, molybdenum, copper, zinc, etc. The present invention relates to a black electroplating bath capable of producing glossy black plating with excellent corrosion resistance by adding additives to a mixed solution of one or more kinds.

It can be used not only for decoration, but also as a material for absorbing solar heat because the emissivity (ε) can be reduced.

<Conventional technology> Conventionally, this type of black plating has included black chromium plating, black nickel plating containing thiocyanic acid, and black plating baths of nickel, di-, keru-tin, and ni-sogeru-zinc using sulfur-containing amino acids as additives. .

<Problems to be solved by the invention> In the conventional black plating mentioned above, the black color "When IJ-1 plating is used, low temperature is required, large current is required, and hexavalent chromium is not produced in wastewater." There are problems with processing and the gloss is poor because of the presence of thiocyanate, and when a black nickel plating bath containing thiocyanic acid is used, a large amount of sodium thiocyanide, which is a cyanogen compound, is used, so water pollution methods are not recommended. Environmental protection subject to Total Cyan regulations -L
It is undesirable, has poor mechanical strength, and has problems with corrosion resistance and discoloration resistance.Furthermore, black plating baths containing sulfur-containing amino acids as additives have the problem of emitting a foul odor peculiar to sulfur-containing amino acids.

<Means to Solve the Problems> The present invention was developed in view of the problems of the prior art, and requires nickel salts, amino acids, and modified amines, in addition to which metal salts for alloys and precipitation inhibitors are added. , buffer, reducing agent, p 1
+Add adjusting agents, etc. as necessary.

As a metal, nickel is suitably in the range of 6 to 40 g and #, and as an amino acid, it is suitably in the range of Ig/ff to loOg/n.

Amine modified product is 0.1g/7 as amine! More than 100
g/(l) is appropriate, and the pH is within the range of 3.0 to 8.5, mainly weak acidity of 4.5 to 6.5. In this case, to lower the pH, sulfuric acid, hydrochloric acid, sulfamine acid,
Citric acid, gluconic acid, acidic sodium sulfite, etc. can be used, and for pI-1, an alkali metal, ammonia, nickel hydroxide, etc. can be used.

Using the above bath, pure nickel black plating or nickel alloy black plating can be obtained, resulting in a film rich in corrosion resistance and discoloration. Also, this black plating bath has no bad odor, so it is environmentally friendly.

<Function> Polyalkylpolyamines are suitable as amines, and the inventors have completed the present invention by discovering that a modified product obtained by reacting a quaternizing agent with a polyalkylpolyamine exhibits a strong blackening tendency. This amine modified product is particularly compatible with nickel, and is homogenized by the presence of one amino acid.

As the polyal 4-lyl polyamine, ethylenediamine,
Propyl noncyamine, butanecyamine, diethylene [
-cyamine, 1-t-pyrenetriamine, 1-lyethylenetetramine, 1-lyethylenepentamine, etc.

Quaternizing agents include epihalohydrin, dichlorohydrin), monochloroacetic acid, monochloroethyl acetate, hensyl chloride, propane chloride, and ethylene chloride.
'Phosphorus etc. can be used.

As amino acids, common amino acids such as glycine, alanine, serine, amino Q8M, toreonine, valine, norhatine, leucine, tyrIsine, proline, aspartic acid, glutamic acid, lysine, ornithine are suitable.

As the anion of the nickel salt, sulfuric acid, hydrochloric acid, acetic acid, sulfamic acid, citric acid, etc. can be used.As the precipitation prevention agent, select from ammonium chloride, potassium chloride, sodium chloride, citric acid, gluconic acid, tartaric acid, etc. I can do it.

Examples of buffering agents include boric acid and sodium acetate, and examples of reducing agents include ascorbic acid, sodium sulfite, and acidic sodium sulfite.

Nickel can be used as an anode, but carbon,
Of course, insoluble anodes such as platinum can also be used, and in the case of nickel and cobalt, metallic cobalt or alloys of nickel and cobalt can also be used, and in the case of nickel and iron, iron or nickel-iron alloys can be used.

Next, the present invention will be explained with reference to Examples and Comparative Examples.

[Example 1] Nickel chloride 60g/II ammonium chloride 30g/β-glycine
20g #30% solution of 1:1 molar reaction of shiconylene triamine and epichlorohydrin] Omρ/β pH 4.5 to 6.5 Stirring Temperature
Electrodeposition was carried out in a Hull cell bath at IA/dm for 23 minutes using a Hull cell plate plated with bright nickel at 45°C. A glossy black nickel film was obtained over the entire surface.

[Example 2] Nickel sulfate 40 g/It Cobalt sulfate 60 g/It Ammonium chloride 60 g/12L-Storium glutamate 20 g/ρ boric acid
20g/ff triethylenetetramine and monochloroethyl acetate reacted at 1 to 2 moles in 30% water solution 20mIV,
/ffpH5.5 Temperature: 40°C I A /dm using a Hull cell plate with glossy Ninogel plating
Electrodeposition was carried out in a Hull cell bath for 3 minutes. A glossy black alloy film was obtained over the entire surface.

[Example 3] Nickel sulfate 40 g/12 Ferrous sulfate 100 g/n Diammonium cuconate 100 g/n Lysine 20 g/ff Polymer of Example 1 20 mff/7! f, l1ll acid
20g/np+-15, O 1 grade
Electrodeposition was carried out in a Hull cell bath at IA/dm for 23 minutes using a Hull cell plate with bright nickel plating at 40°C. A glossy black alloy film was obtained on the entire surface.

[Example 4] Nickel chloride 120 g/l Stannous chloride 3 g/7! Citric acid 60g/7! boric acid
20 g/β-glycine
Add 20 g/n of tetraethylene pentamine to ethylene chloride (1) Lech 1 phosphorus, and then add dichlorohydrin (1)
:I: 30% water volume reacted with 1 mole
20m6/j! A beautiful black film was obtained when plating was performed at IA/dm for 23 minutes using a Hull cell plate plated with bright nickel at pH 6.0 and temperature 45°C.

[Example 5] Nickel sulfate 60 g/ρ manganese sulfate 3 g/ammonium tetrachloride 30 g/7! Sodium sulfate I-3
g/14 I7 glutamic acid mono-lium 10 g#!
Polymer of Example 2] Om//j! pH
5,5 Temperature 40'C IA/dm23 using Hull cell plate with bright nickel plating
After plating for a few minutes, a glossy black nickel-manganese alloy plating film was obtained.

[Example 6] Nickel sulfate 80 g/l Zinc sulfate 10 g/7! Ammonium sulfate 10 g/l boric acid
20 g/ρglycine
20g/l sodium sulfite
5 g/l polymer of Example 1
20+++7! /ffpH5.7 Temperature 50'C A glossy black alloy plating film was obtained by plating at IA/dm for 23 minutes using a bright nickel plated Hull cell plate.

[Comparative Example 1] Nickel chloride 60 g/l Ammonium chloride 30 g/7! glycine
20 g/l pH 5.5 Temperature 45° C. Plating was performed at IA/dm for 23 minutes using a bright nickel plated Hull cell plate, but no black color was obtained and the result was overplating.

[]L Comparative Example 2] Nickel sulfate 120 g//! Nickel chloride 15g/#Ammonium chloride 15g/j! boric acid
20g/R methionine
20g/npl (5.3 Temperature: 35°C) When LA/DM plating was carried out for 23 minutes using a Hull cell plate with bright nickel plating, some parts became black, but most of them had streaks, making it unsuitable for practical use. .

<Effects of the Invention> The electroplating bath according to the present invention does not contain harmful substances such as hexavalent chromium, so wastewater treatment is easy, and it does not emit a bad odor, so it is environmentally friendly.

By carrying out the present invention, it is possible to obtain a black film based on a pure nickel film. Furthermore, by selecting the metal to be alloyed, the performance of corrosion resistance and discoloration resistance can be improved, making it possible to apply it to various uses.

Patent applicant Nihon Kagaku Sangyo Co., Ltd. Agent: Patent attorney Shukichi Nakagawa -r:%n-

Claims (1)

[Claims] An aqueous solution consisting of nickel ions alone or one or more metal ions selected from cobalt, iron, tin, manganese, molybdenum, copper, zinc, etc., nickel ions, amino acids, modified amines, etc. A black electroplating bath made of nickel and nickel alloy, characterized in that it provides a plated object exhibiting a black color.