Patent ID: 8778856

Claim:
A lubricating oil carboxylate-containing detergent additive with improved low temperature performance prepared by a process comprising (a) alkylating a hydroxyaromatic compound with at least one alpha olefin oligomer, derived from substpntially straight chain oligomers of C 8 to C 20 alpha olefins, to thereby produce an alkylhydroxyaromatic compound, and wherein at least 90% of the molecules in the alkylhydroxyaromatic compound have the alkyl group attached at the 4-position or higher from the terminus of the longest chain of the alkyl group, and further wherein the alkyl group comprises at least one hydrocarbon tail of at least 7 carbons; (b) neutralizing the resulting alkylated hydroxyaromatic compound with an alkali metal base to provide an alkali metal salt of the alkylated hydroxyaromatic compound; (c) carboxylating the alkali metal salt from step (b) with carbon dioxide thereby producing an alkylated hydroxyaromatic carboxylic acid alkali metal salt; (d) acidifying the salt produced in step tc) with acid to produce the alkylated hydroxyaromatic carboxylic acid; and (e) overbasing the alkylated hydroxyaromatic carboxylic acid with lime in the presence of carbon dioxide thereby producing an overbased alkylated hydroxyaromatic carboxylate detergent.