| abstract |
A process for the production of a lubricating oil additive concentrate having a TBN greater than 300 comprises reacting at elevated temperature n component (A) a defined salicylic acid derivative, n component (B) an alkaline earth metal base added either in a single addition or in a plurality of additions at internediate points during the reaction, n component (C) at least one compound which is (i) water, (ii) a polyhydric alcohol having 2 to 4 carbon atoms, (iii) a di- (C 3 or C 4 ) glycol, (iv) a tri- (C 2 -C 4 ) glycol, (iv) a mono- or poly-alkylene glycol alkyl ether of the formula (I) n n R(OR.sup.1).sub.x OR.sup.2 (I) n n wherein R is a C 1 to C 6 alkyl group, R 1 is an alkylene group R 2 is hydrogen or a C 1 to C 6 alkyl group and x is an integer from 1 to 6, (vi) a C 1 to C 20 monohydric alcohol, (vii) a C 1 to C 20 ketone, (viii) a C 1 to C 10 carboxylic acid ester, or (ix) a C 1 to C 20 ether, n component (D) a lubricating oil, n component (E) carbon dioxide added subsequent to the, or each, addition of component (B), n component (F) a defined carboxylic acid or derivative, and n component (G) at least one compound which is (i) an inorganic halide of (ii) an ammonium alkanoate or mono-, di-, tri- or tetra-alkyl ammonium formate or alkanoate provided that, when component (G) is (ii), component (F) is not an acid chloride, n the weight ratios of all components being such as to produce a concentrate having a TBN greater than 300. |