Process of inhibiting corrosion of ferrous metals in contact with aqueous solutions of acids

Claim 1

A PROCESS OF INHIBITING CORROSION OF FERROUS METALS IN CONTACT WITH AQUEOUS SOLUTIONS OF ACIDS, SAID ACIDS BEING FROM THE GROUP CONSISTING OF SULFAMIC ACID AND HYDROXY SUBSTITUTED CARBOXYLIC ACIDS WHICH CONTAIN NO MORE THAN 6 CARBON ATOMS IN CHAIN LENGTH AND MIXTURES OF SAID ACIDS, WHICH COMPRISES ADDING TO SUCH SOLUTION CORROSION INHIBITING AMOUNTS OF A CORROSION INHIBITING COMPOSITION WHICH COMPRISES (A) A HIGHER ALKYL SUBSTITUTED ORGANIC NITROGEN BASE FROM THE GROUP CONSISTING OF HIGHER ALKYL SUBSTITUTED MONOAMINES, HIGHER ALKYL SUBSTITUTED ACYCLIC QUATERNARY AMMONIUM COMPOUNDS, HIGHER ALKYL SUBSTITUTED IMIDAZOLINES AND HIGHER ALKYL SUBSTITUTED IMIDAZOL INIUM SALTS, SAID HIGHER ALKYL SUBSTITUTED ORGANIC NITROGEN BASE CONTAINING AT LEAST ONE ALIPHATIC GROUP OF FROM 6 TO 22 CARBON ATOMS IN CHAIN LENGTH AND (B) A THIOUREA FROM THE GROUP CONSISTING OF THIOUREA, N-LOWER ALKYL SUBSTITUTED THIOUREAS, AND N,N''-LOWER ALKYL SUBSTITUTED THIOUREAS, AND ALKYL SUBSTITUTED THIOUREAS HAVING NO SUBSTITUENT GREATER THAN 4 CARBON ATOMS IN CHAIN LENGTH WITH THE WEIGHT RATIO OF A TO B BEING WITHIN THE RANGE OF 1:9 TO 22:1.