Patent ID: 8530394

Claim:
A method for making a sulfur scavenger comprising the steps of: adding a molar excess of at least one aldehyde or aldehyde donor to at least one secondary amine or a primary amine including at least one sterically bulky substituent at a temperature and for a time sufficient to form an oil-soluble sulfur scavenger, where the scavenger comprises substantially monomeric aldehyde-amine adducts derived from the reaction of a single aldehyde and a single amine so that the resulting adducts comprise amines bonded to three different groups where two of the groups can be a part of a ring structure and characterized by compounds of formulas (I), (II) or mixtures thereof: CH 2 R—NR 1 R 2 (I) CH 2 R—(R 4 )NR 3 N(R 5 )—CH 2 R (II) where R is a hydrogen atom (H) or a carbon-containing group, R 1 and R 2 are different, at least one being a sterically hindered carbon-containing group having between 3 and about 24 carbon atoms or R 1 and R 2 can form a ring system, R 3 is a divalent sterically hindered carbon-containing group, R 4 and R 5 are different and are H or sterically hindered carbon-containing group having between 3 and about 24 carbon atoms, provided that both R 4 and R 5 are not H and where one or more hydrogen atoms of R, R 1 , R 2 , R 3 , R 4 , R 5 or mixtures thereof can be replaced by fluorine atoms, chlorine atoms or mixtures thereof, where the CH 2 R groups are derived from the at least one aldehyde of the formula R—CHO, where the temperature is from about 140° F. (60° C.) to about 200° F. (93.3° C.), and where the compounds are adapted to reduce, reduce below a target level or substantially eliminate noxious sulfur-containing species in a fluid.