| abstract |
This invention provides a calcium borate overbased salicylate as an additive for petroleum products which has been overbased with meta-calcium borate having a particle diameter of not larger than 200 angstrom, said meta-calcium borate being prepared by two steps of (1) reacting a mixture of (A) 100 parts by weight of oil-soluble calcium salicylate, (B) 10 to 200 parts by weight, of calcium hydroxide or oxide, (C) 1.5 to 2.5 moles, per mole of said component B, of orthoboric acid, (D) 60 to 200 parts by weight of an alkanol of 1 to 4 carbon atoms, (E) 1 to 40 parts by weight of water and (F) 40 to 1000 parts by weight of a diluent which is a nonpolar organic solvent having a boiling point of 60 DEG C. or higher, at a temperature of from 20 DEG to 120 DEG C. for 2 to 8 hours, and then (2) heating the reaction mixture to 100 DEG to 200 DEG C. thereby to remove the water therefrom by distillation. |