Protective coating compositions for etching formed from chloroprene polymer, carbon black and phenolaldehyde resin, and metal substrate coated therewith

Claim 1

A HEAT CURABLE MASKANT COMPOSITION ADAPTED TO FORM A PLASTIC COATING INERT TO ACIDS AND ALKALI, SAID COMPOSITION CONSISTING ESSENTIALLY OF THE FOLLOWING INGREDIENTS BY WEIGHT: ABOUT 5 TO ABOUT 25% OF NON-COPOLYMERIZED CHLOROPRENE POLYMER, ABOUT 3 TO ABOUT 25% CARBON BLACK, ABOUT 1 TO ABOUT 5% OF PHENOL-FORMALDEHYDE RESIN, FROM ABOUT 1 TO ABOUT 10% CHLORINATED NATURAL RUBBER, ABOUT .08 TO ABOUT 0.6% ALPHA NAPHTHYL AMINE AS ANTIOXIDANT, ABOUT 0.1% TO ABOUT 3% OF AN ACCELERATOR COMPOSITION CONSISTING ESSENTIALLY OF A MIXTURE OF A BUTYRALDEHYDE-MONOBUTYLAMINE CONDENSATION PRODUCT, LITHARGE AND MAGNESIUM OXIDE, THE REMAINDER OF SAID COMPOSITION BEING AN ORGANIC AROMATIC SOLVENT.