Nickel strip formulation
OwnerBarry W. Coffeyinventor
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Abstract
The present invention relates to the chemical stripping of nickel and nickel alloys from metallic and non-metallic substrates wherein at least one compound that is, or can form in solution, a zwitterion acts as a complexing agent for the metal being dissolved and as a buffer to control the pH of the stripping solution. The present invention discloses an electrical method for the rapid stripping of high-phosphorus electroless nickel plating. The present invention provides an electrical process for the efficient removal of the residual smut that ensues from the sulfide ion catalysis of the chemical stripping process.
Claims44
A nickel stripping composition suitable for use in an aqueous electroless stripping bath, said nickel stripping composition consisting essentially of:
- (1) a zwitterion,
- (2) an oxidizing agent in the form of a soluble organic nitro compound,
- (3) a pH-adjusting compound selected from the group consisting of a soluble salt that forms an alkaline solution when dissolved in water, sodium hydroxide and potassium hydroxide, to adjust the stripping solution to an operating pH range of 7 to 11, and
- (4) a compound that forms the sulfide ion in solution to act as a catalyst in the chemical stripping process.
Dependencies are inferred from the claim text.