US5189152A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cellulose solution in water and nmmo
Assignee: Lenzing AG
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Filing: 1991-07-16
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Granted: 1993-02-23
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Expires: 2011-07-16
Abstract
Abstract A solution of cellulose in water and N-methylmorpholine-N-oxide (NMMO) containing 2 to 44% by weight cellulose is stabilized at 0.01 to 1%, preferably 0.1% H2O2 and 0.01 to 2%, preferably 0.1% of an H2O2 stabilizer, preferably oxalic acid or a salt thereof during formation of the solution and during heating to prevent discoloration of the cellulose and reduce the composition of NMMO.
Inventors
- 👤 Peter Hinterholzer
- 👤 Stefan Zikeli
- 👤 Heinrich Firgo
- 👤 Bernd Wolschner
- 👤 Dieter Eichinger
- 👤 Johann Manner
- 👤 Stephan Astegger
- 👤 Karin Weinzierl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:41
CPC Classifications
D; D01; D01F; D01F2/00; D01F2/02; C; C08; C08J; C08J3/00; C08J3/02; C08J3/09; C08J3/091; C08J3/096; C08B; C08B1/00; C08B1/003; C08J2301/00; C08J2301/02
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
39 words
A cellulose solution in water and N-methyl-morpholine-N-oxide which comprises 2 to 44% by weight cellulose and which further comprises 0.01 to 1% H 2 O 2 and 0.01 to 2% of a stablizer for H 2 O 2 .
Claim 2
Dependent Claim
39 words
A cellulose solution in water and N-methyl-morpholine-N-oxide which comprises 2 to 44% by weight cellulose and which further comprises 0.01 to 1% H 2 O 2 and 0.01 to 2% of a stablizer for H 2 O 2 .
Claim 3
Dependent Claim
16 words
The solution defined in claim 1 wherein said stabilizer is oxalic acid or a salt thereof.
Claim 4
Dependent Claim
20 words
The solution defined in claim 1 wherein said H 2 O 2 is present in an amount of about 0.1%.
Claim 5
Dependent Claim
17 words
The solution defined in claim 1 wherein said stabilizer is present in an amount of about 0.1%.
Claim 6
Dependent Claim
16 words
The solution defined in claim 4 wherein said stabilizer is oxalic acid or a salt thereof.
Claim 7
Dependent Claim
20 words
The solution defined in claim 5 wherein said H 2 O 2 is present in an amount of about 0.1%.
Claim 8
Independent Claim
51 words
A method of limiting decomposition of N-methyl-morpholine-N-oxide in a cellulose solution in water and N-methyl-morpholine-N-oxide, containing 2 to 44% by weight cellulose, which comprises maintaining in said solution a concentration of 0.01 to 1% H 2 O 2 and 0.01 to 2% of a stabilizer for H 2 O 2 .
Claim 9
Independent Claim
51 words
A method of limiting decomposition of N-methyl-morpholine-N-oxide in a cellulose solution in water and N-methyl-morpholine-N-oxide, containing 2 to 44% by weight cellulose, which comprises maintaining in said solution a concentration of 0.01 to 1% H 2 O 2 and 0.01 to 2% of a stabilizer for H 2 O 2 .
Claim 10
Dependent Claim
16 words
The method defined in claim 7 wherein said stabilizer is oxalic acid or a salt thereof.
Claim 11
Dependent Claim
22 words
The method defined in claim in claim 7 wherein said H 2 O 2 is present in an amount of about 0.1%.
Claim 12
Dependent Claim
17 words
The method defined in claim 7 wherein said stabilizer is present in an amount of about 0.1%.
Claim 13
Dependent Claim
16 words
The method defined in claim 10 wherein said stabilizer is oxalic acid or a salt thereof.
Claim 14
Dependent Claim
20 words
The method defired in claim 11 wherein said H 2 O 2 is present in an amount of about 0.1%.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-02-23 | 1996-08-24 | 1997-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-02-23 | 2000-08-24 | 2001-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-02-23 | 2004-08-24 | 2005-02-23 | $7700.00 | Window Closed / Lapsed |