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US3962798A Expired / Lapsed US ⏱️ 0.0 years remaining

Process for drying porous materials

Assignee: EIDP Inc
•
Filing: 1975-05-28
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Granted: 1976-06-15
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Expires: 1995-05-28
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Abstract

Abstract Process, suitable for drying water-wet porous materials, for example, textiles, which comprises forcing a displacement liquid through the open interstices of the water-wet porous material to remove the water, the displacement liquid consisting of a water-immiscible, normally liquid organic solvent having a surface-active agent dissolved therein, said displacement liquid having at 25°C. an interfacial tension versus water of no greater than about 10 dynes cm..sup. -1 at 25°C., a density of at least about 1.25 grams cm..sup. -3 and an advancing adhesion tension versus platinum which is positive, and recovering porous material whose open interstices are substantially free of liquid water.

Inventors

  • 👤 Harold L. Jackson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 07:04
CPC Classifications
F; F26; F26B; F26B13/00; F26B13/24; F26B13/001; F26B13/003; F26B5/00; F26B5/005

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 100 words
Process for drying water-wet porous materials, which process comprises forcing a displacement liquid through the open interstices of the water-wet porous material to remove the water, the displacement liquid consisting of a water-immiscible, normally liquid organic solvent having a surface-active agent dissolved therein, said displacement liquid having at 25°C. an interfacial tension versus water of no greater than about 10 dynes cm - 1 at 25°C., a density of at least about 1.25 grams cm. - 3 and an advancing adhesion tension versus platinum which is positive, and recovering porous material whose open interstices are substantially free of liquid water.
Claim 2
Dependent Claim 100 words
Process for drying water-wet porous materials, which process comprises forcing a displacement liquid through the open interstices of the water-wet porous material to remove the water, the displacement liquid consisting of a water-immiscible, normally liquid organic solvent having a surface-active agent dissolved therein, said displacement liquid having at 25°C. an interfacial tension versus water of no greater than about 10 dynes cm - 1 at 25°C., a density of at least about 1.25 grams cm. - 3 and an advancing adhesion tension versus platinum which is positive, and recovering porous material whose open interstices are substantially free of liquid water.
Claim 3
Dependent Claim 26 words
Process of claim 1 wherein the displacement liquid is forced through the open interstices at a flux of at least 0.1 cm. sec. - 1 .
Claim 4
Dependent Claim 16 words
Process of claim 2 wherein the flux is at least 1 cm. sec. - 1 .
Claim 5
Dependent Claim 15 words
Process of claim 1 wherein the displacement liquid is forced through the porous material pulsewise.
Claim 6
Dependent Claim 23 words
Process of claim 1 wherein the interfacial tension of the displacement liquid is no greater than about 3 dynes cm. - 1 .
Claim 7
Dependent Claim 20 words
Process of claim 1 wherein the displacement liquid has a water solubilization index of not more than about 750 ppm.
Claim 8
Dependent Claim 20 words
Process of claim 5 wherein the displacement liquid has a water solubilization index of not more than about 750 ppm.
Claim 9
Dependent Claim 23 words
Process of claim 1 wherein the normally liquid organic solvent is a fluorine-containing compound having a boiling point no greater than about 150°C.
Claim 10
Dependent Claim 11 words
Process of claim 8 wherein the solvent is trichlorofluoromethane or 1,1,2-trichloro-1,2,2-trifluoroethane.
Claim 11
Dependent Claim 26 words
Process of claim 1 wherein the concentration of surface-active agent dissolved in the organic solvent is 0.005-1 weight %, based on the weight of displacement liquid.
Claim 12
Dependent Claim 10 words
Process of claim 10 wherein the surface-active agent is anionic.
Claim 13
Dependent Claim 10 words
Process of claim 10 wherein the surface-active agent is cationic.
Claim 14
Dependent Claim 10 words
Process of claim 10 wherein the surface-active agent is nonionic.
Claim 15
Dependent Claim 33 words
Process of claim 10 wherein the surface-active agent is a mixture of cationic and anionic surface-active agents or is derived from a large cation and a large anion, each of which is surface-active.
Claim 16
Dependent Claim 14 words
Process of claim 10 wherein the concentration of surface-active agent is 0.05-0.5 weight %.
Claim 17
Dependent Claim 11 words
Process of claim 1 wherein the porous substrate is a textile.
Claim 18
Dependent Claim 9 words
Process of claim 16 wherein the textile is yarn.
Claim 19
Dependent Claim 9 words
Process of claim 16 wherein the textile is carpet.
Claim 20
Dependent Claim 7 words
Process of claim 1 carried out continuously.
Claim 21
Dependent Claim 7 words
Process of claim 1 carried out batchwise.
Claim 22
Dependent Claim 39 words
Process of claim 1 wherein the porous material whose open interstices are substantially free of liquid water is contacted with superheated vapor of the organic solvent to remove displacement liquid and substantially all of the liquid phase organic solvent.
Claim 23
Dependent Claim 44 words
Process of claim 21 wherein the porous material, after removal of substantially all of the liquid phase organic solvent, is contacted with dry steam at a temperature sufficient to avoid substantial condensation thereof on the material to displace organic solvent vapor from the material.
Claim 24
Dependent Claim 41 words
Process of claim 22 wherein the organic solvent is trichlorofluoromethane or 1,1,2-trichloro-1,2,2-trifluoroethane and the surface-active agent is a mixture of cationic and anionic surface-active agents or is derived from a large cation and a large anion, each of which is surface-active.
Claim 25
Dependent Claim 11 words
Process of claim 23 wherein the porous material is a textile.

References Cited (Backward Citations)

US3791044A Cited
US3903012A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1979-06-15 1979-12-15 1980-06-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1983-06-15 1983-12-15 1984-06-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1987-06-15 1987-12-15 1988-06-15 $7700.00 Window Closed / Lapsed

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