US5334323A
Expired / Lapsed
US
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Deicing or antiicing fluids for aircraft
Assignee: BASF SE
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Filing: 1991-04-18
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Granted: 1994-08-02
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Expires: 2011-04-18
Abstract
Abstract Deicing/antiicing fluids for aircraft which contain essentially glycols, crosslinked polyacrylic acid, a nonionic surfactant based on alkoxylated C 10 -C 20 alcohols, corrosion inhibitors, a mixture of NaOH and KOH, an antioxidant and water, reduce the loss of lift by having improved runoff characteristics from the wings while giving a refreeze holdover time of not less than 30 minutes.
Inventors
- 👤 Hans Schrimpf
- 👤 Hans Krebs
- 👤 Gert Liebold
- 👤 Guenter Frey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:47
CPC Classifications
C; C09; C09K; C09K3/00; C09K3/18; C09K3/185
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
238 words
A deicing/antiicing fluid for aircraft based on a glycol, water and a crosslinked polyacrylic acid as thickener, consisting essentially of: a) 40-70% by weight of a glycol selected from the group consisting of the alkylene glycols of 2 or 3 carbon atoms and oxyalkylene glycols o from 4 to 6 carbon atoms, or a mixture thereof, b) 0.1-1.0% by weight of a crosslinked polyacrylic acid which in the form of a 0.5% strength by weight aqueous solution at pH 7.0 a Brookfield viscometer at 20 rpm, c) 0.02-1.5% by weight of a nonionic surfactant formed from an alcohol of from 10 to 20 carbon atoms reacted with from 1 to 10 molecules of a low molecular weight alkoxide, d) 0.05-2.0% by weight of one or more corrosion inhibitors, e) 0.2-0.7% by weight of a mixture of potassium hydroxide and sodium hydroxide containing up to 70% by weight of potassium hydroxide, or of pure sodium hydroxide, to the fluid pH to 7.0-9.5, f) 0.01-0.1% by weight of an antioxidant, and g) water to 100% by weight, all the weight percentages being based on the weight of the fluid, and wherein the deicing/antiicing fluid has a holdover time of at least about 30 minutes as measured by the AEA freezing rain endurance test and a viscosity of from about 2000 mPa.s to not greater than about 4000 mPa.s when measured at 20° C. using a Brookfield viscometer at 0.3 rpm.
Claim 2
Dependent Claim
238 words
A deicing/antiicing fluid for aircraft based on a glycol, water and a crosslinked polyacrylic acid as thickener, consisting essentially of: a) 40-70% by weight of a glycol selected from the group consisting of the alkylene glycols of 2 or 3 carbon atoms and oxyalkylene glycols o from 4 to 6 carbon atoms, or a mixture thereof, b) 0.1-1.0% by weight of a crosslinked polyacrylic acid which in the form of a 0.5% strength by weight aqueous solution at pH 7.0 a Brookfield viscometer at 20 rpm, c) 0.02-1.5% by weight of a nonionic surfactant formed from an alcohol of from 10 to 20 carbon atoms reacted with from 1 to 10 molecules of a low molecular weight alkoxide, d) 0.05-2.0% by weight of one or more corrosion inhibitors, e) 0.2-0.7% by weight of a mixture of potassium hydroxide and sodium hydroxide containing up to 70% by weight of potassium hydroxide, or of pure sodium hydroxide, to the fluid pH to 7.0-9.5, f) 0.01-0.1% by weight of an antioxidant, and g) water to 100% by weight, all the weight percentages being based on the weight of the fluid, and wherein the deicing/antiicing fluid has a holdover time of at least about 30 minutes as measured by the AEA freezing rain endurance test and a viscosity of from about 2000 mPa.s to not greater than about 4000 mPa.s when measured at 20° C. using a Brookfield viscometer at 0.3 rpm.
Claim 3
Dependent Claim
38 words
A fluid as claimed in claim 1, wherein component (c) is an oxo alcohol of from 10 to 20 carbon atoms in the carbon chain which has been ethoxylated with from 1 to 10 molecules of ethylene oxide.
Claim 4
Dependent Claim
27 words
A fluid as claimed in claim 1, wherein component (e) is a mixture of potassium hydroxide and sodium hydroxide in a ration of from 2.5:1 to 1:2.5.
Claim 5
Dependent Claim
68 words
A fluid as claimed in claim 1, which contains components a) to f), in the following amounts: a) from 50 to 60% by weight b) from 0.2 to 0.6% by weight c) from 0.02 to 1.5% by weight d) from 0.1 to 2.0% by weight e) from 0.2 to 0.7% by weight f) from 0.01 to 0.1% by weight g) water to make up to 100% by weight.
Claim 6
Dependent Claim
26 words
A fluid as claimed in claim 1, wherein said glycol is selected from the group consisting of 1,2-propylene glycol, 1,3-propylent glycol, diethylene glycol and mixtures thereof.
Claim 7
Dependent Claim
29 words
A fluid as claimed in claim 2, wherein said nonionic surfactant is an oxo alcohol of from 13 to 15 carbon atoms, ethoxylated with 3 molecules of ethylene oxide.
Claim 8
Dependent Claim
14 words
A fluid as claimed in claim 6, wherein said holdover time is 35 times.
Claim 9
Dependent Claim
14 words
A fluid as claimed in claim 7, wherein said holdover time is 37 minutes.
Claim 10
Dependent Claim
14 words
A fluid as claimed in claim 8, wherein said holdover time is 39 minutes.
Claim 11
Dependent Claim
20 words
A fluid as claimed in claim 1, said nonionic surfactant being present in an amount of from 0.02 to 0.3%.
Claim 12
Dependent Claim
20 words
A fluid as claimed in claim 10, said nonionic surfactant being present in an amount of from 0.05 to 0.3%.
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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) | 1997-08-01 | 1998-01-31 | 1998-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-01 | 2002-01-31 | 2002-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-01 | 2006-01-31 | 2006-08-02 | $7700.00 | Window Closed / Lapsed |