Abstract: Process for preparation of conductive circuit utilizing two photohardenable layers on substrate which may contain a conductive circuit, the upper photohardenable layer becoming hardenable and nontacky when exposed to short wavelengths of radiation (ultraviolet) the lower photohardenable layer being tacky and sensitive to long wavelength radiation (visible light). The photohardenable layers are imagewise exposed through a dichromic phototool (black/yellow also having clear areas) and the unhardened image areas are solvent developed revealing tacky areas. The tacky areas are treated with metal or alloy particles or plating catalyst material, and the metallized or catalyzed image is electrolessly plated. Multilayer conductive circuits can be prepared.

Abstract: Ferromagnetic chromium dioxide is produced in a continuous operation by feeding a preheated paste of hydrated chromium oxides and additives into a twin screw reactor, reacting at elevated temperature and pressure for a short time while venting oxygen and steam, injecting water near the end of the reaction zone to form a viscous chromium dioxide-water mixture, and cooling while passing through a pressure letdown extruder.