Oil-soluble anionic-graft polymer of ethylene-propylene copolymer and anionically polymerizable monomer having utility as multifunctional V. I. improver for lubricating oils
AssigneeExxon Research & Engineering Co.
InventorsRobert L. Elliott, John Brooke Gardiner
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Abstract
An oil-soluble anionic-graft polymer of an anionically polymerizable monomer, preferably an ethylenically unsaturated nitrogen-containing monomer, e.g. acrylonitrile, and an anion of an oxidized copolymer of ethylene and at least one C.sub.3 to C.sub.50 alpha monoolefin, e.g. propylene, said anionic-graft polymer in its preferred form containing from about 0.005 to 2% by weight nitrogen and having a number average molecular weight of from about 1000 to 500,000, has utility as a multifunctional V.I. improver or dispersant for lubricating oils.
Claims24
An oil soluble anionic-graft polymer having a number average molecular weight in the range of about 1,000 to 500,000 while containing in the range of about 0.005 to 2 wt. % nitrogen and being useful as an oil additive having dispersancy properties, said oil soluble polymer being a graft polymer of:
- 1. an anionically polymerizable monomer containing in the range of about 3 to 50 carbon atoms and at least one electron withdrawing group in such proximity to an olefinic bond that said bond is activated, said monomer being seleeted from the group consisting of:
- a. N,N (di C.sub.1-10 hydrocarbyl) carbodiimides;
- b. monomers of the formula:
- ##STR5## wherein X is oxygen or an NR" group;
- n is 2 to 5;
- R' and R" are hydrogen or a C.sub.1 to C.sub.4 alkyl group;
- and R'" and R"" are C.sub.1 to C.sub.12 hydrocarbyl groups;
- and
- c. nitrile monomers of the formulae:
- ##STR6## wherein R.sup.v is hydrogen or lower alkyl and X is selected from the group consisting of hydrogen, halogen, cyano and lower alkyl;
- and, (2) an anion of an oxidized ethylene copolymer comprising about 20 to 80 mole % ethylene and about 20 to 80 mole % propylene.
An oil soluble graft polymer according to claim 12, wherein said monomer is said N,N (di C.sub.1-10 hydrocarbyl) carbodiimide.
A lubricating oil composition comprising a major amount of mineral lubricating oil and about 0.1 to 10 wt. % of an oil soluble anionic-graft polymer having a number average molecular weight in the range of about 1,000 to 500,000 while containing in the range of about 0.005 to 2 wt. % nitrogen and being useful as an oil additive having dispersancy properties, said oil soluble polymer being a graft polymer of:
- 1. an anionically polymerizable monomer containing in the range of about 3 to 50 carbon atoms and at least one electron withdrawing group in such proximity to an olefinic bond that said bond is activated, said monomer being selected from the group consisting of:
- a. N,N (di C.sub.1-10 hydrocarbyl) carbodiimides;
- b. monomers of the formula:
- ##STR7## wherein X is oxygen or an NR" group;
- n is 2 to 5;
- R' and R" are hydrogen or a C.sub.1 to C.sub.4 alkyl group;
- and R"' and R"" are C.sub.1 to C.sub.12 hydrocarbyl groups;
- and
- c. nitrile monomers of the formulae:
- ##STR8## wherein R.sup.v is hydrogen or lower alkyl and X is selected from the group consisting of hydrogen, halogen, cyano and lower alkyl;
- and, (2) an anion of an oxidized ethylene copolymer comprising about 20 to 80 mole % ethylene and about 20 to 80 mol % propylene.
A process of preparing an anionic-graft polymer comprising the steps of:
- 1. contacting an oxidized ethylene copolymer comprising about 20 to 80 mole % ethylene and about 20 to 80 mole % propylene, having an oxygen content of from about 0.005 to 6% based on the weight of said copolymer, with an alkyllithium compound of from 3 to 10 carbons under anhydrous conditions and inert atmosphere for a period of between 1 and 25 hours and at a temperature between about 20.degree. C. and 100.degree. C., whereby an anion of said oxidized ethylene copolymer is produced;
- and
- 2. contacting said anion with an anionically polymerizable monomer at a temperature between about 0.degree. C. and about 100.degree. C. and for a period of between about 0.2 and 15 hours in the presence of a base whereby an anionic-graft polymer is produced, and wherein said anionically polymerizable monomer is selected from the group consisting of:
- a. N,N (di C.sub.1-10 hydrocarbyl) carbodiimides;
- b. monomers of the formula:
- ##STR9## wherein X is oxygen or an NR" group;
- n is 2 to 5;
- R' and R" are hydrogen or a C.sub.1 to C.sub.4 alkyl group;
- and R'" and R"" are C.sub.1 to C.sub.12 hydrocarbyl groups;
- and c. nitrile monomers of the formulae:
- ##STR10## wherein R.sup.v is hydrogen or lower alkyl and X is selected from the group consisting of hydrogen, halogen, cyano and lower alkyl.
Dependencies are inferred from the claim text.