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US 4,229,311 AGranted
Lubricating oil additives
AssigneeRohm Co., Ltd.
InventorsFranz Wenzel, Ulrich Schoedel, Heinz Jost, Hans Pilz
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AssigneeRohm Co., Ltd.
InventorsFranz Wenzel, Ulrich Schoedel, Heinz Jost, Hans Pilz
Estimating the term…
What is disclosed are methods for making polymer-in-oil solutions, useful for improving the viscosity-temperature relationship and low-temperature properties of lubricating oils when added thereto, which methods comprise polymerizing a methacrylic acid ester of an alcohol having 8 to 18 carbon atoms onto a polyolefin polymer of an olefinic hydrocarbon monomer having 2 to 4 carbon atoms in an oil solution of the polyolefin and ester monomers, then adding further polyolefin polymer to the solution and finally graft copolymerizing a polymerizable heterocyclic compound having a basic nitrogen atom in the ring thereof onto the resulting mixed polymers as backbone polymers or, in the alternative, separately graft copolymerizing a polymerizable heterocyclic compound having a basic nitrogen atom in the ring thereof onto a first backbone polymer which is itself a graft copolymer, in an oil solution, of a methacrylic acid ester of an alcohol having 8 to 18 carbon atoms on a polyolefin polymer of an olefinic hydrocarbon monomer having two to four carbon atoms and further graft copolymerizing a polymerizable heterocyclic compound having a basic nitrogen atom in the ring thereof onto a polyolefin polymer of the type described above and then combining the two graft copolymers thus formed to produce the desired polymer-in-oil solution.
A method for making a polymer-in-oil solution, useful for improving the viscosity-temperature relationship and low-temperature properties of lubricating oils when added thereto, which method comprises polymerizing a methacrylic acid ester of an alcohol having 8 to 18 carbon atoms in a solution, in a lubricating oil, of a polyolefin polymer of an olefinic hydrocarbon monomer having two to four carbon atoms, the oil solution of said polyolefin having a viscosity of less than 15,000 centistokes at 100.degree. C., adding further polyolefin polymer of the type defined herein to said solution, and then graft copolymerizing a polymerizable heterocyclic compound having a basic nitrogen atom in the ring thereof onto the resulting mixed polymers as backbone polymers.
A method for making a polymer-in-oil solution, useful for improving the viscosity-temperature relationship and low-temperature properties of lubricating oils when added thereto, which method comprises polymerizing a methacrylic acid ester of an alcohol having 8 to 18 carbon atoms in a solution, in a lubricating oil, of a polyolefin polymer of an olefinic hydrocarbon monomer having two to four carbon atoms, the oil solution of said polyolefin having a viscosity of more than 15,000 centistokes at 100.degree. C., whereby an oil solution of a first graft copolymer is formed, further graft copolymerizing, onto said first graft copolymer as a backbone, a polymerizable heterocyclic compound having a basic nitrogen atom in the ring thereof to form a second graft copolymer, separately graft copolymerizing such a polymerizable heterocyclic compound onto a polyolefin polymer, in a solution in a lubricating oil, of an olefinic hydrocarbon monomer having two to four carbon atoms to form a third graft copolymer, and then combining the oil solutions of said second graft copolymer and said third graft copolymer to form an oil solution comprising from 20 percent to 55 percent by weight of polymer, wherein said methacrylate ester comprises from 50 percent to 80 percent of the polymer content and the amount of polymerizable heterocyclic compound is from one to 30 percent by weight of said methacrylate ester.
Dependencies are inferred from the claim text.