Dispersant-viscosity improvers for lubricating oil compositions
AssigneeThe Lubrizol Corporation
InventorsJohn C. Smoggie, Richard M. Lange
Life of this patent
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Abstract
Graft copolymers useful as a dispersant-viscosity improver for lubricating oil compositions comprise a hydrocarbon polymer having graft polymerized thereon at least two nitrogen containing units, at least one of the nitrogen containing units being derived from at least one of a neutral N-(lower hydrocarbyl group)- (meth)acrylamide and a neutral N,N-di-(lower hydrocarbyl group)- (meth)acrylamide, wherein the total number of carbon atoms in the lower hydrocarbyl groups does not exceed 9, and at least one of the nitrogen containing units being derived from at least one vinylic nitrogen containing heterocyclic compound.
Claims27
A graft copolymer comprising a hydrocarbon polymer having graft polymerized thereon at least two nitrogen containing units, at least one of the nitrogen containing units being derived from at least one of N-methyl-, N-ethyl-, N,N-dimethyl-, N,N-diethyl-, and N-propyl-(meth)acrylamide, and at least one of the nitrogen containing units being derived from at least one vinylic nitrogen containing heterocyclic compound.
A process for preparing graft copolymers comprising simultaneously grafting onto a hydrocarbon polymer, under free radical conditions, at least two nitrogen containing monomers, wherein one of the monomers comprises at least one of N-methyl-, N-ethyl-, N,N-dimethyl-, N,N-diethyl-, and N-propyl-(meth)acrylamide and one of the monomers comprises at least one vinylic nitrogen containing heterocyclic compound.
The process of claim employing a total of from about 0.1 to about 5 moles nitrogen containing units per 10,000 weight average molecular weight units of hydrocarbon polymer.
A method for improving the efficiency of the free radical initiated grafting of vinylic nitrogen containing heterocyclic monomers onto hydrocarbon polymers said method comprising simultaneously co-grafting with a mixture of the vinylic nitrogen containing heterocyclic monomer and at least one of N-methyl-, N-ethyl-, N,N-dimethyl-, N,N-diethyl-, and N-propyl-(meth)acrylamide.
Dependencies are inferred from the claim text.