Patent US4583984A successfully refreshed from Google Patents.
US4583984A
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Procedure for treating cellulose derivative fibres
Assignee: Neste Oyj
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Filing: 1983-03-25
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Granted: 1986-04-22
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Expires: 2003-03-25
Abstract
Abstract The present invention concerns improving the properties of cellulose carbamate fibres. The wet strength properties in particular can be improved by treating the fibres with alkalis or organic bases, aiming to reduce the number of carbamate groups. The procedure may also be applied in the manufacturing of regenerated cellulose fibres.
Inventors
- 👤 Olli Turunen
- 👤 Jouko Huttunen
- 👤 Kurt Ekman
- 👤 Vidar Eklund
- 👤 Leo Mandell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:50
CPC Classifications
D; D01; D01F; D01F2/00; C; C08; C08B; C08B16/00; D01F11/00; D01F11/02; D06; D06M; D06M11/00; D06M11/32; D06M11/36; D06M11/38; D06M13/00; D06M13/322; D06M13/325
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
89 words
Method of regulating the wet properties of cellulose carbamate fibres or filaments, which comprises treating such fibres or filaments with a solution of an alkali or of an organic base of a concentration and at a temperature and for a period of time such that the number of carbamate groups in the cellulose carbamate is reduced without adversely affecting the properties of the resulting cellulose carbamate fibres or filaments which thus remain in solid form, thereby increasing wet strength and decreasing wet stretchability of the thus-treated fibres or filaments.
Claim 2
Dependent Claim
89 words
Method of regulating the wet properties of cellulose carbamate fibres or filaments, which comprises treating such fibres or filaments with a solution of an alkali or of an organic base of a concentration and at a temperature and for a period of time such that the number of carbamate groups in the cellulose carbamate is reduced without adversely affecting the properties of the resulting cellulose carbamate fibres or filaments which thus remain in solid form, thereby increasing wet strength and decreasing wet stretchability of the thus-treated fibres or filaments.
Claim 3
Dependent Claim
16 words
The method of claim 1 comprising treating the fibres or filaments with NaOH or KOH solution.
Claim 4
Dependent Claim
19 words
The method of claim 2, comprising treating the fibres or filaments with 0.1 to 2% NaOH or KOH solution.
Claim 5
Dependent Claim
17 words
The method of claim 2, comprising treating the fibres or filaments with 0.1 to 4% KOH solution.
Claim 6
Dependent Claim
19 words
The method of claim 1, comprising treating the fibres or filaments with a tetramethylammonium hydroxide or ethylene diamine solution.
Claim 7
Dependent Claim
21 words
The method of claim 5, comprising treating the fibres or filament with 0.1 to 10% tetramethylammonium hydroxide or ethylene diamine solution.
Claim 8
Dependent Claim
24 words
The method of claim 1, comprising treating the fibres or filaments at a temperature in the range from room temperature to about 100° C.
Claim 9
Dependent Claim
30 words
The method of claim 1, comprising treating the fibres or filaments for a time sufficient to remove substantially all of the carbamate groups, thus obtaining regenerated cellulose fibres or filaments.
Claim 10
Dependent Claim
28 words
The method of claim 1, comprising treating the fibres or filaments for a time sufficient to form regenerated cellulose fibres or filaments of less than 10% alkali solubility.
Claim 11
Dependent Claim
143 words
In a method for preparing improved cellulose carbamate fibres or filaments comprising the steps of reacting cellulose and urea at elevated temperatures to form cellulose carbamate, dissolving the thus-formed cellulose carbamate in an alkaline solution to prepare a spinning solution from which cellulose carbamate can be spun, and spinning the thus-prepared solution through an acid precipitation solution to form fibres or filaments, the improvement comprising the step of treating the thus-spun fibres or filaments with a solution of an alkali or an organic base of a concentration and at a temperature and for a period of time such that the number of carbamate groups in the cellulose carbamate is reduced without adversely affecting the properties of the resulting cellulose carbamate fibres or filaments which thus remain in solid form, thereby increasing wet strength and decreasing wet stretchability of the thus-treated fibres or filaments.
Claim 12
Dependent Claim
143 words
In a method for preparing improved cellulose carbamate fibres or filaments comprising the steps of reacting cellulose and urea at elevated temperatures to form cellulose carbamate, dissolving the thus-formed cellulose carbamate in an alkaline solution to prepare a spinning solution from which cellulose carbamate can be spun, and spinning the thus-prepared solution through an acid precipitation solution to form fibres or filaments, the improvement comprising the step of treating the thus-spun fibres or filaments with a solution of an alkali or an organic base of a concentration and at a temperature and for a period of time such that the number of carbamate groups in the cellulose carbamate is reduced without adversely affecting the properties of the resulting cellulose carbamate fibres or filaments which thus remain in solid form, thereby increasing wet strength and decreasing wet stretchability of the thus-treated fibres or filaments.
Claim 13
Dependent Claim
27 words
In the method of claim 10, the improvement comprising the step of treating the thus-spun fibres or filaments with a solution of 0.1 to 4% alkali concentration.
Claim 14
Dependent Claim
27 words
In the method of claim 11, the improvement comprising the step of treating the thus-spun fibres or filaments with a solution of 0.1 to 2% alkali concentration.
Claim 15
Dependent Claim
29 words
In the method of claim 10, the improvement comprising the step of treating the thus-spun fibres or filaments with a solution of 0.1 to 10% concentration of organic base.
Claim 16
Dependent Claim
31 words
In the method of claim 10, the improvement comprising the step of treating the thus-spun fibres or filaments at a temperature in the range from room temperature to about 100° C.
Claim 17
Dependent Claim
36 words
In the method of claim 14, the improvement comprising the step of treating the thus-spun fibres or filaments at a temperature of about 100° C. for a period of time of up to about one hour.
Claim 18
Dependent Claim
37 words
In the method of claim 10, the improvement comprising the step of treating the thus-spun fibres or filaments for a time sufficient to remove substantially all of the carbamate groups, thus obtaining regenerated cellulose fibres or filaments.
Claim 19
Dependent Claim
35 words
In the method of claim 10, the improvement comprising the step of treating the thus-spun fibres or filaments for a time sufficient to form regenerated cellulose fibres or filaments of less than 10% alkali solubility.
References Cited (Backward Citations)
US3560139A
Cited
FI61033B
Cited
US4404369A
Cited
US4456749A
Cited
US4486585A
Cited
WO1983003433A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-04-21 | 1989-10-21 | 1990-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-21 | 1993-10-21 | 1994-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-21 | 1997-10-21 | 1998-04-22 | $7700.00 | Window Closed / Lapsed |