US4526620A
Expired / Lapsed
US
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Cellulose carbamate solutions
Assignee: Neste Oyj
•
Filing: 1983-11-30
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Granted: 1985-07-02
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Expires: 2003-11-30
Abstract
Abstract The invention relates to cellulose carbamate solutions having improved capacity for fiber spinning or film formation therefrom. The addition of urea to the aqueous alkali in which the cellulose carbamate is dissolved results in an increase in the amount of cellulose carbamate that can be dissolved and a decrease in the viscosity and clogging number of the solution as compared to such solutions without urea.
Inventors
- 👤 Johan Selin
- 👤 Jouko Huttunen
- 👤 Olli Turunen
- 👤 Vidar Eklund
- 👤 Kurt Ekman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:40
CPC Classifications
C; C08; C08B; C08B16/00; C08K; C08K5/00; C08K5/16; C08K5/21
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
65 words
Solution from which cellulose carbamate fiber or film can be formed, said solution comprising a predetermined amount of cellulose carbamate dissolved in a predetermined amount of aqueous alkali solution containing urea, said solution having a viscosity which is lower than the viscosity of a solution of the same predetermined amount of cellulose carbamate in the same predetermined amount of aqueous alkali solution without said urea.
Claim 2
Dependent Claim
65 words
Solution from which cellulose carbamate fiber or film can be formed, said solution comprising a predetermined amount of cellulose carbamate dissolved in a predetermined amount of aqueous alkali solution containing urea, said solution having a viscosity which is lower than the viscosity of a solution of the same predetermined amount of cellulose carbamate in the same predetermined amount of aqueous alkali solution without said urea.
Claim 3
Dependent Claim
16 words
Solution according to claim 1 wherein the amount of urea is between about 1-10% by weight.
Claim 4
Dependent Claim
17 words
Solution according to claim 2 wherein the amount of cellulose carbamate is between about 2-10% by weight.
Claim 5
Dependent Claim
11 words
Solution according to claim 1 wherein said alkali is sodium hydroxide.
Claim 6
Dependent Claim
11 words
Solution according to claim 3 wherein said alkali is sodium hydroxide.
Claim 7
Dependent Claim
16 words
Solution according to claim 1 wherein the amount of alkali is between about 6-11% by weight.
Claim 8
Dependent Claim
15 words
Solution according to claim 3 wherein the amount of alkali is about 6-11% by weight.
Claim 9
Dependent Claim
76 words
Method of dissolving cellulose carbamate for the formation of a solution from which cellulose carbamate fiber or film can be formed, said method comprising dissolving a predetermined amount of cellulose carbamate in a predetermined amount of aqueous alkali solution containing urea, the resulting solution having a viscosity which is lower than the viscosity of a solution of the same predetermined amount of cellulose carbamate in the same predetermined amount of aqueous alkali solution without said urea.
Claim 10
Dependent Claim
76 words
Method of dissolving cellulose carbamate for the formation of a solution from which cellulose carbamate fiber or film can be formed, said method comprising dissolving a predetermined amount of cellulose carbamate in a predetermined amount of aqueous alkali solution containing urea, the resulting solution having a viscosity which is lower than the viscosity of a solution of the same predetermined amount of cellulose carbamate in the same predetermined amount of aqueous alkali solution without said urea.
Claim 11
Dependent Claim
16 words
Method according to claim 8 wherein the amount of urea is between about 1-10% by weight.
Claim 12
Dependent Claim
21 words
Method according to claim 8 wherein said dissolution is effected at a temperature of between about +3° C. and -5° C.
Claim 13
Dependent Claim
21 words
Method according to claim 9 wherein said dissolution is effected at a temperature of between about +3° C. and -5° C.
Claim 14
Dependent Claim
95 words
Method of dissolving cellulose carbamate for the formation of a solution from which cellulose carbamate fiber or film can be formed, said method comprising adding a predetermined amount of an alkali solution containing urea to a predetermined amount of an aqueous suspension of cellulose carbamate, the resulting solution having a viscosity which is lower than the viscosity of a solution of the same predetermined amount of cellulose carbamate in the same predetermined amount of aqueous alkali solution without said urea, whereby cellulose carbamate fiber or film can be formed effectively from the lower viscosity solution.
Claim 15
Dependent Claim
95 words
Method of dissolving cellulose carbamate for the formation of a solution from which cellulose carbamate fiber or film can be formed, said method comprising adding a predetermined amount of an alkali solution containing urea to a predetermined amount of an aqueous suspension of cellulose carbamate, the resulting solution having a viscosity which is lower than the viscosity of a solution of the same predetermined amount of cellulose carbamate in the same predetermined amount of aqueous alkali solution without said urea, whereby cellulose carbamate fiber or film can be formed effectively from the lower viscosity solution.
Claim 16
Dependent Claim
16 words
Method according to claim 12 wherein the amount of urea is between about 1-10% by weight.
Claim 17
Dependent Claim
30 words
Method according to claim 12 wherein the addition of the aqueous alkali solution to the aqueous suspension is effected at a temperature of between about +3° C. and -5° C.
Claim 18
Dependent Claim
32 words
Method according to claim 13 wherein the addition of the alkali solution to the aqueous suspension of cellulose carbamate is effected at a temperature of between about +3° C. and -5° C.
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) | 1988-07-01 | 1988-12-31 | 1989-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-01 | 1992-12-31 | 1993-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-01 | 1996-12-31 | 1997-07-02 | $7700.00 | Window Closed / Lapsed |