Method for coating metallic strips

Claim 1

IN A METHOD FOR APPLYING A SUBSTANTIALLY UNIFORM COATING OF AN AQUEOUS SOLUTION OF A PHOTOSENTIVE MATERIAL TO AT LEAST P ONE SURFACE OF A SUBSTANTIALLY VERTICALLY MOVING METALLIC STRIP FOR BEING LATER SUBJECTED TO A PHOTOETCHING PROCESS WHEREIN SAID METHOD COMPRISES WITHDRAWING SAID METALLIC STRIP IN A SUBSTANTIALLY VERTIAL DIRECTION FROM SAID AQUEOUS SOLUTION OF PHOTOSENSITIVE MATERIAL WITHIN A CONTAINER ADAPTED FOR CONTAINING SAID MATERIAL AND THEREAFTER EXPOSING SAID MATERIAL ON SAID SURFACE TO A PREESTABLISHED HEAT SOURCE WHEREBY SAID MATERIALS DRIED, THE IMPROVEMENT COMPRISING: PROVIDING AN AQUEOUS SOLUTION OF A PHOTOSENSITIVE MATERIAL SELECTED FROM THE GROUP CONSISTING OF AQUEOUS SOLUTION OF PHOTOSENSITIVE MATERIALS HAVING A SECIFIC GRAVITY WITHIN THE RANGE FROM 0.950 TO ABOUT 1. 016 AND A VISCOSITY WITHIN THE RANGE OF FROM ABOUT 12.0 TO ABOUT 28.0 CENTIPOISES AND AQUEOUS SOLUTION OF PHHOTOSENSITIVE MATERIALS HAVING A SPECIFIC GRAVITY WITHIN THE RANGE OF FROM ABOUT 1.030 TO ABOUT 1.040 AND A VISCOSITY WITHIN THE RANGE OF FROM ABOUT 3.0 TO ABOUT 8.0 CENTIPOSIES: AND WITHDRAWING SAID METALLIC STRIP FROM SAID AQUEOUS SOLUTION AT A RATE WITHIN THE RANGE OF FROM ABOUT 8 INCHES PER MINUTES TO ABOUT 50 INCHES PER MINUTE TO PROVIDE A PREDETERMINED TIME PERIOD WITHIN THE RANGE OF FROM ABOUT 1 MINUTE TO ABOUT 11 MINUTES IMMEDIATELY AFTER SAID WITHDRAWING OF SAID STRIP FROM SAID SOLUTION AND PRIOR TO SAID EXPOSING OF SAID STRIP TO SAID HEAT SOURCE WHEREBY SAID PHOTOSENSITIVE MATERIAL ON SAID SURFACE OF SAID STRIP IS PERMITTED TO FLOW IN A SUBSTANTIALLY DOWNWARD DIRECTION IN SUCH A MANNER SO AS TO ACHIEVE UNIFORMITY OF THICKNESS.