Shell Oil Comapny

John A Morris

John E Gorman

A process is provided according to the present invention comprising the steps of: functionalizing a base polymer by grafting alpha-beta unsaturated carboxylic acid, anhydride or ester to a base polymer, the base polymer being selected from the group of hydrogenated polymer of a conjugated diolefin and a copolymer of conjugated diolefins and monoalkenyl arenes, the grafting being performed in a blending device capable of imparting high mechanical energy and in the presence of 3 to 15 percent by weight, based on base polymer, of a suitable diluent oil; reacting the functionalized polymer with an amine; and recovering an animated polymer. This process results in a lower level of scission, crosslinking and coupling than processes which are essentially oil free. The product of this process is an excellent lubricating oil viscosity index improver and additionally has dispersant characteristics.

Dispersant viscosity index improvers

A process for incorporating carboxy and/or carboxyl derivative functionality into a hydrocarbon polymer which is substantially free of ethylenic unsaturation. The functionalization is accomplished by contacting the functionalizing agent or agents with the polymer in the presence of a free radical initiator in a blending apparatus capable of imparting high mechanical energy into the reaction medium. The blending apparatus is preferably an extruder and most preferably a non-intermeshing twin screw extruder. The amount of degradation resulting from the presence of a free radical initiator and the high mechanical shear at the elevated temperatures employed during the contacting is reduced by effecting the contacting in a suitable diluent. Similarly, the amount of polymer crosslinking and/or coupling is reduced through the use of a suitable diluent. The polymer is maintained in the molten phase during the reaction.

Method for preparing functionalized block copolymers

Alkoxy silane compounds such as vinyl-triethoxy-silane are more readily grafted to block copolymers in the presence of an amount of zinc oxide between about 0.15% and 1.5% by weight of the block copolymer. The silane modified block copolymer prepared with zinc oxide exhibits greater resistance to gel formation than silane-modified block copolymer prepared without the zinc oxide.

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Katy, TX, United States of America

John A Morris