Technique for electrodeposition of water-based polymeric coating

Claim 1

Method for the electrodeposition of a water based polymeric coating having a thickness ranging from 2 to 12 microns upon wire, cable and the conductive portion of printed circuit boards which comprises the steps of: (a) providing an electrolytic cell containing an electrolyte comprising an aqueous 2-20 percent alkaline solution of a novolak resin having a molarity ranging from 0.1 to 0.5, said resin being selected from the group consisting of phenol formaldehyde copolymers, cresol formaldehyde copolymers and mixtures thereof, the molecular weight of the resin ranging from 1,500-6,000, (b) immersing cathode and anode members in the electrolyte, the anode member providing the conductive substrate to be coated, (c) impressing a difference of potential across the anode and cathode such that the initial current density ranges from 10-30 milliamperes per square centimeter thereby resulting in electrolytic deposition of a polymeric coating on the anode, (d) cross linking the said coating with a cross linking agent, and (e) baking the resultant cross linked coating at a temperature ranging from 150°-250° C for a time period ranging from 2-5 minutes.