Abstract: A synthesis technology of overbased calcium naphthenate is presented. The effect of process conditions including promoters, water and CO2 on the synthesis reactions is investigated. A co-promoter having antioxiding group is introduced and the optimal process conditions are obtained. In consequence, an overbased calcium naphthenate sample is synthesized by adding 100%~110% CO2 into a system containing 40% CaOH, 20% methanol, 15% promoter B3, 20% co-promoter C and 5% water. The obtained sample having calcium content over 10% and total base number more than 300 mgKOH/g, as compared with a conventional overbased calcium naphthenate product, said synthesized sample exhibits better antioxidation performance.

Key words: detergent, overbased calcium naphthenate, synthesis technology, performance study