Patents Assigned to Orobis Limited
  • Polymer composition viscosity index improver additive and lubricating oil containing the additive
    Patent number: 4194057
    Abstract: A viscosity index improver additive composition contains, as one component, a vinyl aromatic/conjugated diene polymer of specific structure and composition and, as a second component an ethylene/C.sub.3 to C.sub.18 alpha olefin copolymer of specific composition and viscosity. Preferably the composition also contains a polybutene of defined molecular weight.
    Type: Grant
    Filed: May 17, 1978
    Date of Patent: March 18, 1980
    Assignee: Orobis Limited
    Inventors: David Brankling, John Crawford
  • Viscosity index improver composition
    Patent number: 4081390
    Abstract: A composition suitable as a V.I. improver additive for lubricants comprising from 1 to 15% of a vinyl aromatic sequential block copolymer having an M.sub.n in the range 25,000 to 125,000 and containing from 10 to 40% b.w. of the vinyl aromatic component, from 5 to 45% of a polybutene having an M.sub.n in the range 5,000 to 60,000 and the remainder of the composition comprising a solvent neutral base oil, all percentages being by weight.
    Type: Grant
    Filed: May 6, 1976
    Date of Patent: March 28, 1978
    Assignee: Orobis Limited
    Inventor: Adrian Richardson