Metal-resin composite and process for its production

Claim 1

A process of producing a metal-resin composite, capable of controlling the pH of a solution, which permeates through the resin to the metal, to within the range of from 4 to 12, comprises providing a first solution or dispersion of at least one resin selected from the group consisting of epoxy resins, phenolic resins, acrylic resins, polyamide resins, alkyd resins, melamine resins, urea-formaldehyde resins, polybutadiene resins, polyester resins, silicone resins, polyolefin resins, urethane resins and polystyrene resins, said first solution or dispersion having dispersed therein at least one particulate metal compound selected from the group consisting of oxides, hydroxides, carbonates, acid carbonates, borates, perborates, phosphates, acid phosphates, silicates, aluminates, stannates, tungstates, molybdates, chromates, manganates, permanganates and carboxylates of Group I A and Group II A metals of the Periodic Table, the amount of said metal compound in said first solution or dispersion being 1-500 parts by weight per 100 parts by weight of said resin, coating said first solution or dispersion, having said metal compound dispersed therein, on a metal substrate, heating the thus coated substrate at a temperature and for a time sufficient to evaporate the solvent for said resin and cure said resin, thus producing a first resin layer adhering to said metal substrate, coating the surface of said first resin layer with a second solution or dispersion of said resin having dispersed therein at least one particulate metal selected from the group consisting of aluminum, chromium, zinc, tin, nickel, cobalt and manganese, or an alloy thereof, in an amount of 1-500 parts by weight per 100 parts by weight of said resin, and heating the thus coated resin layer at a temperature and for a time sufficient to evaporate the solvent for said resin and cure said resin, thus producing a second resin layer adhering to said first resin layer.