Patent US4281081A successfully refreshed from Google Patents.
US4281081A
Expired / Lapsed
US
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Process for graft copolymerization
Assignee: Roehm GmbH Darmstadt
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Filing: 1979-02-01
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Granted: 1981-07-28
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Expires: 1999-02-01
Abstract
Abstract What is disclosed are the method of making a lubricating-oil additive which improves the viscosity index and has a dispersing and detergent action, which method comprises graft copolymerizing, onto an oil-soluble base polymer, from 0.5 to 10 parts of a polymerizable lactam together with 0.1 to 3 parts of a polymerizable N-heterocyclic compound, said parts being by weight of said base polymer, and the lubricating-oil additives so produced.
Inventors
- 👤 Heinz Jost
- 👤 Hellmuth Knoell
- 👤 Gerhard Markert
- 👤 Horst Pennewiss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:24
CPC Classifications
C; C10; C10M; C10M149/00; C10M149/02; C10M149/10; C08; C08F; C08F255/00; C08F255/02; C08F255/04; C08F265/00; C08F265/04; C10M2217/00; C10M2217/02; C10M2217/028; C10M2217/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
83 words
The method of making a lubricating-oil additive which improves the viscosity index and has a dispersing and detergent action, which method comprises graft copolymerizing 0.5 to 10 percent of N-vinyl pyrrolidone together with 0.1 to 3 percent of N-vinyl imidazole onto an oil-soluble base polymer selected from the group consisting of polyalkyl methacrylic acid esters of alcohols having at least 8 carbon atoms and mixtures of said polyalkyl methacrylic acid esters with a polyolefin, said percentages being by weight of said base polymer.
Claim 2
Independent Claim
83 words
The method of making a lubricating-oil additive which improves the viscosity index and has a dispersing and detergent action, which method comprises graft copolymerizing 0.5 to 10 percent of N-vinyl pyrrolidone together with 0.1 to 3 percent of N-vinyl imidazole onto an oil-soluble base polymer selected from the group consisting of polyalkyl methacrylic acid esters of alcohols having at least 8 carbon atoms and mixtures of said polyalkyl methacrylic acid esters with a polyolefin, said percentages being by weight of said base polymer.
Claim 3
Dependent Claim
16 words
A method as in claim 1 wherein said graft copolymerization is carried out in an extruder.
Claim 4
Dependent Claim
24 words
A method as in claim 1 wherein the ratio by weight of said N-vinyl pyrrolidone to said N-vinyl imidazole is from 2:1 to 5:1.
Claim 5
Dependent Claim
37 words
A method as in claim 1 wherein from 1 to 5 percent of N-vinyl pyrrolidone and from 0.2 to 2 percent of N-vinyl imidazole, by weight of said base polymer, are graft copolymerized onto said base polymer.
Claim 6
Dependent Claim
10 words
A lubricating-oil additive prepared by the method of claim 1.
Claim 7
Dependent Claim
10 words
A lubricating-oil additive prepared by the method of claim 2.
References Cited (Backward Citations)
US3089832A
Cited
US3067163A
Cited
GB1244435A
Cited
US4146489A
Cited
US4146489B1
Cited
US4098710A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-07-27 | 1985-01-26 | 1985-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-07-27 | 1989-01-26 | 1989-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-07-27 | 1993-01-26 | 1993-07-28 | $7700.00 | Window Closed / Lapsed |