Powderless etching bath and method of etching

Claim 1

AN EMULSIFIED POWDERLESS ETCHING BATH CONSISTING ESSENTIALLY OF 1 TO 25 PERCENT BY VOLUME OF 37.5 PERCENT BY WEIGHT HYDROCHLORIC ACID; 1 TO 10 PERCENT BY VOLUME OF AN ORGANIC, WATER-IMMISCIBLE LIQUID; 0.1 TO 5 PERCENT BY WEIGHT OF A HYDROPHOBIC-HYDROPHILIC FILMING AGENT SELECTED FROM THE GROUP CONSISTING OF SULFONATED ORGANIC COMPOUNDS AND SULFATED ORGANIC COMPOUNDS; AND THE BALANCE BEING WATER; SAID ORGANIC, WATER-IMMISCIBLE LIQUID COMPRISING AT LEAST 65 PERCENT BY VOLUME OF A MEMBER OF THE GROUP CONSISTING OF AN AROMATIC HYDROCARBON, A DERIVATIVE OF AN AROMATIC HYDROCARBON HAVING AN AROMATIC NUCLEUS AND BEING PREDOMINATLY AROMATIC IN CHARACTER, AND MIXTURES THEREOF, AND UP TO 35 PERCENT BY VOLUME OF A WATER-IMMISCIBLE ORGANIC SOLVENT, SAID ORGANIC, WATER-IMMISCIBLE LIQUID BEING (1) SUBSTANTIALLY STABLE IN THE SAID BATH AT AT TEMPERATURE IN THE RANGE OF 50-120* F., (2) SUBSTANTIALLY IMMISCIBLE WITH THE WATER (3) SUBSTANTIALLY NON-REACTIVE WITH THE HYDROCHLORIC ACID AND THE METAL TO BE ETCHED, AND (4) A LIQUID AT BATH TEMPERATURES; AND SAID FILMING AGENT BEING FURTHER CHARACTERIZED AS CONTAINING AT LEAST 10 CARBON ATOMS IN THE HYDROPHOBIC PORTION OF THE MOLECULE, AND HAVING A SOLUBILITY, BY WEIGHT, OF AT LEAST 0.01 PERCENT IN EACH OF THE WATER AND THE ORGANIC, WATER-IMMISCIBLE LIQUID.