Claims
- 1. A graft copolymer of:
- (a) a substrate consisting essentially of a hydrogenated polymer or copolymer selected from the group consisting of (i) homopolymers of conjugated dienes having from 4 to 6 carbon atoms, (ii) copolymers of at least two conjugated dienes having from 4 to 6 carbon atoms, and (iii) copolymers of conjugated dienes having from 4 to 6 carbon atoms with styrene, said hydrogenated polymer or copolymer having a residual olefinic unsaturation after hydrogenation of from 0 to 5% of the units contained therein, a weight average molecular weight from 30,000 to 100,000 and a distribution of the molecular weights defined by a ratio M.sub.w /M.sub.n lower than 2; and
- (b) graft polymerized chains of (i) at least one vinyl compound selected from the group consisting of N-vinylpyrrolidone, N-vinylimidazole and vinylpyridine, and (ii) at least one unsaturated ester selected from the group consisting of methyl, butyl, dodecyl, stearyl and 2-hydroxyethyl acrylates and methacrylates.
- 2. A graft copolymer according to claim 1, wherein said vinyl compound is N-vinylimidazole or N-vinylpyrrolidone.
- 3. A graft copolymer according to claim 1, in which said hydrogenated polymer is obtained from a polymer of 1,3-butadiene containing from 25 to 80% of 1,2 units.
- 4. A graft copolymer according to claim 1, in which said hydrogenated copolymer is obtained from a copolymer containing from 10 to 90% of butadiene units and from 10 to 90% of isoprene units.
- 5. A graft copolymer according to claim 1, in which said hydrogenated copolymer is obtained from a copolymer containing from 20 to 80% of units derivating from at least one conjugated diene having from 4 to 6 carbon atoms and from 20 to 80% of styrene units.
- 6. A graft copolymer according to claim 1, in which the proportion of the graft polymerized chain of vinyl compound is from 1 to 40% by weight.
- 7. A graft copolymer according to claim 1, in which the proportion of the graft polymerized chain of vinyl compound is from 1 to 10% by weight.
- 8. A lubricating composition comprising a major proportion of lubricating oil and a proportion of at least one graft copolymer according to claim 1, which is sufficient to improve both the viscosity index and the dispersing power of said lubricating oil.
- 9. A composition according to claim 8, in which the proportion of graft copolymers is from 0.1 to 10% by weight.
- 10. A composition according to claim 8, in which the proportion of graft copolymer is from 0.5 to 5% by weight.
- 11. A graft copolymer of:
- (a) a substrate consisting essentially of a hydrogenated polymer or copolymer selected from the group consisting of (i) homopolymers of conjugated dienes having from 4 to 6 carbon atoms, (ii) copolymers of at least two conjugated dienes having from 4 to 6 carbon atoms, and (iii) copolymers of conjugated dienes having from 4 to 6 carbon atoms with styrene, said hydrogenated polymer or copolymer having a residual olefinic unsaturation after hydrogenation of from 0 to 5% of the units contained therein, a weight average molecular weight from 30,000 to 100,000 and a distribution of the molecular weights defined by a ratio M.sub.w /M.sub.n lower than 2; and
- (b) graft polymerized chains of at least one vinyl compound selected from the group consisting of diethylaminoethyl acrylate, diethylaminoethyl methacrylates, and N-methacryloyloxyethylmorpholine.
- 12. A graft copolymer according to claim 11, wherein said at least one vinyl compound is diethylaminoethyl methacrylate.
Priority Claims (1)
Number |
Date |
Country |
Kind |
74 39511 |
Dec 1974 |
FRX |
|
Parent Case Info
This is a division of application Ser. No. 637,393 filed Dec. 3, 1975, now U.S. Pat. No. 4,085,055 issued Apr. 18, 1978.
US Referenced Citations (10)
Divisions (1)
|
Number |
Date |
Country |
Parent |
637393 |
Dec 1975 |
|