Patent ID: 7405185

Claim:
A process for preparing Group II metal overbased sulfurized alkylphenols which comprises: forming a reaction mixture by combining a sulfurized alkylphenol wherein the alkyl group contains a sufficient number of carbon atoms to render oil-soluble the resulting Group II metal overbased sulfurized alkylphenol, an alkanol containing about 6 to about 15 carbon atoms, a Group II metal oxide, hydroxide or C 1 -C 6 alkoxide, a C 2 -C 10 alkylene glycol and contacting with an alkylene carbonate selected from ethylene carbonate or a mono-alkyl or di-alkyl substituted ethylene carbonate, said alkylene carbonate having the following structure: wherein R 1 and R 2 are independently hydrogen or alkyl containing one to three carbon atoms; and wherein the contacting is carried out for a time and at a temperature sufficient to form in situ carbon dioxide and alkylene glycol, or a reacting equivalent, to form a product comprising a Group II earth metal overbased sulfurized alkylphenol.