Mobil Oil Corporation

Frederick Charles Loveless

Thomas S Coolbaugh

Demetreos N Matthews

Wan-Li Liu

Ellen Bernice Brandes

The invention provides dispersants and dispersant viscosity index improvers which include polymers of conjugated dienes which have been hydrogenated and functionalized. The dispersant substances include compositions including a copolymer of two different conjugated dienes, a copolymer of a p-alkylstyrene and a conjugated diene, or a homopolymer of a conjugated diene. The polymers are selectively hydrogenated to produce polymers which have highly controlled amounts of unsaturation, permitting highly selective functionalization. Also provided are lubricant fluids, such as mineral and synthetic oils, which have been modified in their dispersancy and/or viscometric properties by means of the dispersant substances of the invention. Also provided are methods of modifying the dispersancy and/or viscometric properties of lubricating fluids such as mineral and synthetic lubricating oils. The dispersant substances may also include a carrier fluid to provide dispersant concentrates.

Dispersants and dispersant viscosity index improvers from selectively

An epoxidized linear block copolymer which prior to epoxidation comprises at least one triblock I--B--I, wherein I is a block of a polymerized conjugated diene of at least 5 carbon atoms, such as isoprene, and B is a block of a polymer of a conjugated diene, different from that polymerized to form the I blocks, of at least 4 carbon atoms, such as 1,3-butadiene. The B block may be selectively hydrogenated before or after epoxidation so that they contain substantially no ethylenic unsaturation, while the epoxidation reaction forms epoxy groups from double bonds in the I blocks. Also disclosed is an alternative epoxidized solid linear block copolymer which prior to epoxidation contains at least one triblock wherein the first polymer block is a copolymer of an aryl-substituted olefin, such as styrene, and the conjugated diene used to polymerize the block I, the second or middle block is a polymer of the diene used to polymerize the block B, and the third polymer block is the same as the first polymer block. In this alternative copolymer, the middle block may also be selectively hydrogenated, so that it contains substantially no ethylenic unsaturation while the epoxidation reaction forms epoxy groups from double bonds in the first and third blocks. The disclosure also includes epoxidized solid linear random copolymers and solid star-branched block and random copolymers made from the same monomers as the linear block copolymers, and methods for producing the foregoing epoxidized polymers.

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Princeton, NJ, United States of America

Frederick Charles Loveless