Patent ID: 6228817
Filing Date: 2001-05-08
Classification: C07C,C08C,C08F,C10L,C10M,C10N

Abstract:
A dispersant substance for modifying the dispersancy or viscometric properties of a fluid, comprising:a copolymer of a first conjugated diene and a second conjugated diene, wherein:said first conjugated diene comprises at least one relatively more substituted conjugated diene having at least five carbon atoms and the formula: ##STR15##wherein R.sup.1 --R.sup.6 are each hydrogen or a hydrocarbyl group, provided that at least one of R.sup.1 --R.sup.6 is a hydrocarbyl group, provided that after polymerization, the unsaturation of the polymerized conjugated diene of formula (1) has the formula: ##STR16##wherein R.sup.I, R.sup.II, R.sup.III and R.sup.IV are each hydrogen or a hydrocarbyl group, provided that either both R.sup.I and R.sup.II are hydrocarbyl groups or both R.sup.III and R.sup.IV are hydrocarbyl groups; andsaid second conjugated diene comprises at least one relatively less substituted conjugated diene different from the first conjugated diene and having at least four carbon atoms and the formula: ##STR17##wherein R.sup.7 --R.sup.12 are each hydrogen or a hydrocarbyl group, provided that after polymerization, the unsaturation of the polymerized conjugated diene of formula (3) has the formula: ##STR18##wherein R.sup.V, R.sup.VI, R.sup.VII and R.sup.VIII are each hydrogen or a hydrocarbyl group, provided that one of R.sup.V or R.sup.VI is hydrogen, one of R.sup.VII or R.sup.VIII is hydrogen, and at least one of R.sup.V, R.sup.VI, R.sup.VII and R.sup.VIII is a hydrocarbyl group; andwherein said copolymer has been functionalized by a method comprising:selectively hydrogenating said copolymer to provide a selectively hydrogenated copolymer;functionalizing said selectively hydrogenated copolymer to provide a functionalized copolymer having at least one polar functional group; andpost treating the functionalized copolymer with a post- treating agent.