← Back to Patent Explorer
US5334323A Expired / Lapsed US ⏱️ 0.0 years remaining

Deicing or antiicing fluids for aircraft

Assignee: BASF SE
•
Filing: 1991-04-18
•
Granted: 1994-08-02
•
Expires: 2011-04-18
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

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%.

References Cited (Backward Citations)

GB1285862A Cited
DE2423893A1 Cited
US4064065A Cited
US4358389A Cited
EP0231869A1 Cited
US4954279A Cited

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

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag