Adhesion of metal coatings of polypyromellitimides
First Claim
1. A method for improving adhesion of a metal layer to the surface of a non-fluorinated polypyromellitimide which consists essentially of contacting said surface first with a material consisting essentially of aqueous sulfuric acid of at least about 90% concentration by weight for at least about 20 seconds, and then with a material consisting essentially of an aqueous alkali metal hydroxide solution of at least about 2 M concentration for at least about 20 seconds with optional rinsing with water after each contact and subsequently depositing said metal layer on said surface.
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Abstract
The adhesion of metal coatings, such as those produced by electroless or physical vapor deposition, on polypyromellitimide surfaces is improved by prior treatment of the surface with concentrated sulfuric acid, followed by aqueous alkali metal hydroxide of at least about 2M concentration. Further metal may be deposited on the surface, for example by electrolytic or physical vapor deposition, following the original metal deposition.
14 Citations
15 Claims
- 1. A method for improving adhesion of a metal layer to the surface of a non-fluorinated polypyromellitimide which consists essentially of contacting said surface first with a material consisting essentially of aqueous sulfuric acid of at least about 90% concentration by weight for at least about 20 seconds, and then with a material consisting essentially of an aqueous alkali metal hydroxide solution of at least about 2 M concentration for at least about 20 seconds with optional rinsing with water after each contact and subsequently depositing said metal layer on said surface.
Specification