Patent ID: 7964543

Claim:
A method for preventing metal ion catalyzed oxidation and polymerization reactions in a hydrocarbon medium comprising sequestering the metal ion by the addition of an effective amount of a Mannich condensation product prepared by a Mannich condensation of: (a) a polyisobutyl-substituted hydroxyaromatic compound having the formula wherein R 1 is polyisobutyl derived from polyisobutene containing at least 50 weight percent methylvinylidene isomer and having a number average molecular weight in the range of about 400 to about 5,000, R 2 is hydrogen or lower alky having one carbon atom to about 10 carbon atoms, and R 3 is hydrogen or —OH; (b) a formaldehyde or an aldehyde having the formula wherein R′ is branched or linear alkyl having one carbon atom to about 10 carbon atoms, cycloalkyl having from about 3 carbon atoms to about 10 carbon atoms, aryl having from about 6 carbon atoms to about 10 carbon atoms, alkaryl having from about 7 carbon atoms to about 20 carbon atoms, or aralkyl having from about 7 carbon atoms to about 20 carbon atoms; (c) an amino acid or ester derivative thereof having the formula wherein W is —[CHR″]— m wherein each R″ is independently H, alkyl having one carbon atom to about 15 carbon atoms, or a substituted-alkyl having one carbon atom to about 10 carbon atoms and one or more substituents selected from the group consisting of amino, amido, benzyl, carboxyl, hydroxyl, hydroxyphenyl, imidazolyl, imino, phenyl, sulfide, or thiol; and m is an integer from one to 4, A is hydrogen or alkyl having one carbon atom to about 6 carbon atoms; and (d) an alkali metal base.