GB474885A - A process for producing lubricating oil or additions to lubricating oil - Google Patents

Abstract

Viscous oils of high viscosity index, used as lubricants or additions to lubricating oils, are obtained by polymerizing gaseous alkenes at increased pressures and at temperatures above 125 DEG C. to products containing large proportions of gasoline, removing the gasoline, and then further polymerizing the residue in presence of a catalyst at temperatures below 125 DEG C. and at pressures lower than those used in the first stage. The product may be refined, e.g. by hydrogenation, sulphuric acid, or bleaching earth. Alkenes specified are propene, butenes, mixtures thereof, and gas mixtures containing them as the larger part of the unsaturated constituents, e.g. gases obtained by cracking paraffin wax or mineral oils or residues. The polymerization of the higher-boiling fraction may take place in presence of benzene, naphthalene, or mineral oils rich in aromatics. Suitable catalysts are aluminium chloride and boron fluoride. Catalysts are preferably present in the first polymerization; phosphoric acid, sulphuric acid, benzene-sulphonic acid, bleaching earth, and floridine are suitable. Both polymerizations may be in stages. In an example, cracking gas is passed over a phosphoric acid-kieselguhr catalyst at 200--250 DEG C. and 10--15 atmos. until 90 per cent of the olefines is converted; the product is distilled to 180 DEG C., 87,5 per cent passing over as a high anti-knock gasoline; the residue is polymerized at 100 DEG C. and atmospheric pressure for 5 hours in presence of 4 per cent of aluminium chloride.ALSO:Viscous oils of high viscosity index, used as lubricants or additions to lubricating oils, are obtained by polymerizing gaseous olefines at raised pressures and at temperatures above 125 DEG C. to products consisting largely of gasolene, removing the gasolene, and further polymerizing the residue in presence of a catalyst at lower pressures and at temperatures below 125 DEG C. The product may be refined, e.g. by hydrogenation, sulphuric acid, or bleaching earth. Alkenes specified are butenes, propene, mixtures thereof, and gas mixtures containing them as the larger part of the unsaturateds, e.g. gases obtained by cracking paraffin wax or mineral oil or residues. The polymerization of the residue may take place in presence of benzene, naphthalene, or mineral oils rich in aromatics. In an example, cracking gas is passed over a phosphoric acid-kieselguhr catalyst at 200--250 DEG C. and 10--15 atmos. until 90 per cent of the olefines is polymerized; the product is distilled to 180 DEG C., 87,5 per cent passing over as a high anti-knock gasolene; the residue is polymerized at 100 DEG C. and atmospheric pressure for 5 hours in presence of 4 per cent of aluminium chloride.