JPS59226170A - Electroless nickel plating solution - Google Patents

Abstract

PURPOSE:To provide a titled plating soln. which has good throwing power and permits plating at a low temp. by adding a rhodanine compd. to a soln. prepd. by contg. Ni ion complexed by pyrophosphate, glycolate, etc. and a boron hydride compd. and adjusting the pH thereof. CONSTITUTION:Ni sulfate is used as a soluble Ni salt and a complexing agent as much as Ni ion can be thoroughly completely complexed or more than said amt. is used. Pyrophosphate, glycolate, malate and citrate are used as the complexing agent. A boron hydride compd. [NaBH4, (CH3)2NHBH3, KBH4] is added as the reducing agent to the soln. and the soln. is made alkaline by NH4OH, KOH, NaOH, etc. for the purpose of preventing decomposition and adjusting pH. A slight amt. of rhodanine or the deriv. of rhodanine, for example, p-dimethyl aminobenzylidene rhodanine is added to such soln. by which a plating soln. having a long soln. life is obtd. If such soln. is used, plating is accomplished at a relatively low temp. on the inside wall of a pipe having about 0.5mm. inside diameter and on plastics as well.

Description

[Detailed Description of the Invention] (1) Purpose There are many electroless nickel plating solutions currently known, but they do not allow plating to deposit on the inner wall of tubes with an inner diameter of about 0.5 mm, and even if they do, the adhesion is poor. Extremely bad, and the operating temperature is also high. For example, in the case of Schumar plating (manufactured by Nippon Kanigen Co., Ltd.), which is a typical electroless nickel plating solution, no plating is deposited on the inner wall of the tube with an inner diameter of 0.5 mm, and the operating temperature is extremely high (80°C to 90°C). .

If plated at low temperatures, the color tone will be poor and there will be no gloss, so it is not suitable for gluing plastics or items with complex shapes. In the case of this plating liquid, the material is ABS resin or a solid tube, and it has good coverage even on inner walls with an inner diameter of about 0.5 mm, so it can be plated uniformly. Also, when plating plastics, it is necessary to change the contacts when moving from electroless plating to electric plating, but this plating solution has good coverage, so there is no need for this, and the temperature is low, so it is suitable for plating plastics. ing. From the above, this plating solution is suitable for plating on complex-shaped objects, the inner walls of thin tubes (with an inner diameter of about 0.5 mm), and plastics.

Continuous use is possible by replenishing the missing ingredients.
The liquid life is semi-permanent.

The deposited layer has a glossy coating with good adhesion and is thick (10
(μ/60 minutes) is characterized by a fast plating speed. (2) The main plating solution uses nickel sulfate as a soluble nickel salt, and contains as much or more complexing agent as possible to completely complex all nickel ions. use. Potassium pyrophosphate, or sodium glycolate, sodium malate, or sodium citrate is used as the complexing agent.

Dimethylamine boron is used as the reducing agent, and NH4OH or KO is used to prevent the decomposition of dimethylamine boron and adjust the pH.
Use H or NaOH, etc. By adding a small amount of p-dimethylaminobenzylidene rhodanine as a stabilizer to the entire plating solution, the plating solution becomes extremely stable and can be used continuously for a long time.

The liquid composition is as follows: Pyrophosphate type nickel sulfate 20 g/l - 40 g/l Potassium pyrophosphate 30 g/l - 90 g/l Dimethylamine boron 0.06 mol/l - 0.1 mol/lp-dimethylamino benzylidene rhodanine
1ppm/l~30ppm/l Temperature 40℃~70℃pH
10 (Adjusted with NH3) Glycolate type nickel sulfate 20 g/l ~ 40 g/l Sodium glycolate 60 g/l ~ 120 g/l Dimethylamine boron 0.06 mol/l ~ 0.1 mol/lp-dimethylaminobenzylidene rhodium Nin
1ppm/l~30ppm/l Temperature 40℃~70℃pH
7-8 (Adjusted with NH3) Citric acid type nickel sulfate 20g/l - 40g/l Sodium citrate 1g/l - 10g/l Dimethylamine boron 0.01 mol/l - 0.1 mol/
lp-dimethylaminobenzylidene rhodanine
1ppm/l~30ppm/l temperature
40℃～60℃pH
7 to 10 (adjusted with NH3) Malate type nickel sulfate 20 g/l to 40 g/l Potassium malate 5 g/l to 50 g/l Dimethylamine boron 0.06 mol/l to 0.1 mol/
lp-dimethylaminobenzylidene rhodanine
1ppm/l~30ppm/l temperature
40℃～60℃pH
8-11 Examples Example 1 Pyrophosphate type nickel sulfate 30g/l Potassium pyrophosphate 60g/l Dimethylamine boron 0
．． 08 mol/lp-dimethylaminobenzylidene rhodanine 10 ppm/l pH 10 Temperature 69°C Plating speed 8.4 μ/60 minutes
(Material Shinchiyuu) Example 2
Glycolate type nickel sulfate 30g/l Sodium glycolate 60g/l Dimethylamine boron 0
．． 06 mol/lp-dimethylaminobenzylidene rhodanine 10 ppm/l temperature
(42±2)℃pH
7.6 Plating speed 3.7μ/30 minutes
(Material Shinchiyuu) Example 3
Citric acid type nickel sulfate 30g/l Sodium citrate 8g/l Dimethylamine boron 0.06 mol/lp-dimethylaminobenzylidene rhodanine
10ppm/lpH 10
(Adjust with NH3) Plating speed 5μ/3
0 minute temperature 43℃ (Material is new) Example 4 Malate type nickel sulfate 30g/l malic acid
30g/l dimethylamine boron 0
．． 06 mol/lp-dimethylaminobenzylidene rhodanine 10ppm/lpH
10 (adjusted with NH3) temperature
52℃ Plating speed 1μ/10 minutes
(Material: Shinchiyu) (3) Effect: The actual plating liquid has good coverage and long liquid life, so there is no need to change the contacts when using plastic plating, and the material is Shinchiyu or ABS resin with an inner diameter of about 5 mm. Even the inner wall of a thin tube can be coated with a uniform thickness. It has a long liquid life, and by replenishing missing components, it can be used continuously and has a fast plating speed (10μ/60 minutes), which allows for thick, glossy and adhesive coatings.

Claims (1)

[Claims] Nickel ion complexed with pyrophosphate, glycolate, malate, or citrate and a borohydride compound [NaBH4, (CH3)2N] as a reducing agent
HBH3, KBH4,] is made alkaline with NH3 or an alkaline compound to adjust the pH, and the solution is stabilized with rhodanine or a rhodanine derivative. Electroless nickel plating solution.