Electrophoretic imaging metal-toner fluid dispersion
AssigneeMinnesota Mining and Manufacturing Company
InventorsWilliam M. Lamanna, Robin E. Wright, Hsin-Hsin Chou
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Abstract
The present invention relates to toner fluid dispersions comprising electrostatically charged colloidal elemental metal particles dispersed in nonconductive organic liquid media of low dielectric constant and containing a charge-inducing surfactant. In other aspects, processes are disclosed for electrophoretically depositing the colloidal elemental metal particles of the toner fluid to produce nonconductive, continuous coatings or patterns and methods of enhancing the coatings or patterns to make them electrically conductive.
Claims23
A toner fluid dispersion comprising electrostatically charged, colloidal elemental non-ferromagnetic metal particles dispersed in an electrically nonconductive organic carrier liquid of dielectric constant less than 3.5 and having a volume resistivity greater than 10.sup.12 ohm.cm, and an amount of a soluble surfactant effective to charge and stabilize said dispersion, said metal particles having sizes in the range of 1 to 100 nm.
A method comprising the steps:
- (a) providing a toner fluid dispersion comprising electrostatically charged, colloidal, elemental metal particles dispersed in an electrically nonconductive organic carrier liquid of dielectric constant less than 3.5 and having a volume resistivity greater than 10.sup.12 ohm.cm, and providing a dielectric or photoconductive substrate,
- (b) electrophoretically and irreversibly depositing the charged, colloidal, elemental metal particles of the toner fluid in a continuous or imagewise fashion on at least one of the surfaces of said substrate using standard electrographic techniques to provide a nonconductive, colloidal, elemental metal coating thereon, and
- (c) optionally, in the case of a catalytically active colloidal, elemental metal, subjecting the resulting colloidal metal coated substrate to an electroless metal plating solution to induce selective metal plating on the elemental colloidal metal coated portions of the substrate surface, to provide a second elemental metallic coating on said portions of the substrate surface which is electrically conductive.
Dependencies are inferred from the claim text.