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US4151069A
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Olefin-dicarboxylic anhydride copolymers and esters thereof are dewaxing aids
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1974-10-17
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Granted: 1979-04-24
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Expires: 1994-10-17
Abstract
Abstract Olefin-dicarboxylic anhydride copolymers and their ester derivatives, having C18 to C50 linear alkyl side chains are filtration aids in solvent dewaxing of waxy lubricating oils.
Inventors
- 👤 Albert Rossi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:19
CPC Classifications
B; B01; B01D; B01D9/00; B01D9/005; C; C10; C10G; C10G73/00; C10G73/02; C10G73/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
122 words
In a solvent dewaxing process for the separation of wax from a distillate lubricating oil fraction having about 5 to 30 weight percent wax, by the steps which include diluting the oil with solvent, chilling the diluted oil to a temperature in the range of -7° C. to -40° C. to form solid wax crystals and filtering to remove said wax crystals; the improvement which comprises incorporating into said oil prior to formation of said wax crystals a wax crystallization modifying amount of an oil-soluble dewaxing aid copolymer having a number average molecular weight in the range of about 1500 to 20,000, said copolymer consisting essentially of 1-olefin of 30 to 50 carbon atoms copolymerized in essentially equi-molar proportions with maleic anhydride.
Claim 2
Dependent Claim
122 words
In a solvent dewaxing process for the separation of wax from a distillate lubricating oil fraction having about 5 to 30 weight percent wax, by the steps which include diluting the oil with solvent, chilling the diluted oil to a temperature in the range of -7° C. to -40° C. to form solid wax crystals and filtering to remove said wax crystals; the improvement which comprises incorporating into said oil prior to formation of said wax crystals a wax crystallization modifying amount of an oil-soluble dewaxing aid copolymer having a number average molecular weight in the range of about 1500 to 20,000, said copolymer consisting essentially of 1-olefin of 30 to 50 carbon atoms copolymerized in essentially equi-molar proportions with maleic anhydride.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-04-23 | 1982-10-23 | 1983-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-04-23 | 1986-10-23 | 1987-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-04-23 | 1990-10-23 | 1991-04-24 | $7700.00 | Window Closed / Lapsed |