| abstract |
1529333 Lubricants OROBIS Ltd 30 April 1976 [22 May 1975 5 Dec 1975] 22400/75 and 49994/75 Heading C5F An additive concentrate comprises (i) 1 to 15% by weight of a block copolymer having a number average molecular weight of 25,000 to 125,000 comprising 10 to 40% by weight of vinyl-aromatic units (e.g. styrene) and isoprene units to 100%, (ii) 5 to 45% of polybutene having a number average molecular weight of 5,000 to 60,000, and (iii) a solvent neutral oil. The copolymer may be hydrogenated. The concentrate increases the V.I. of oils to which it is added, and may be used together with known additives. In an Example, these are bissuccinimide, calcium phenate, calcium sulphonate and zinc phosphorodithioate. |