Suitable carboxylic acids which can be employed herein include those represented by the following formulas ##STR3## wherein R1 is a hydrocarbyl group or a sulfur, halogen, nitro or hydroxyl substituted hydrocarbyl group having from about 1 to about 72 carbon atoms, preferably from about 10 to about 36 carbon atoms, most preferably an alkyl group having from about 12 to about 24 carbon atoms.