EP0057105A2
Expired / Lapsed
EP
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Method of producing alkali-soluble cellulose carbamate
Assignee: Neste Oyj
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Filing: 1982-01-27
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Granted: —
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Expires: 2002-01-27
Abstract
Abstract An alkali-soluble cellulose derivative is produced by treating cellulose with liquid ammonia having urea dissolved therein, removing the ammonia, resulting in cellulose having urea distributed therethrough, and heating the thus obtained cellulose-urea to cause reaction between the urea and cellulose and form alkali-soluble cellulose carbamate. This cellulose carbamate can be precipitated from alkaline solution in the form of cellulose carbamate film or fibre.
Inventors
- 👤 Jouka I. Huttunen
- 👤 Olli Turunen
- 👤 Leo Mandel
- 👤 Vidar Eklund
- 👤 Kurt Ekman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 14:42
CPC Classifications
C; C08; C08B; C08B15/00; C08B15/05; C08B15/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
93 words
A method of producing an alkali-soluble cellulose compound, which method comprises treating cellulose with a liquid ammonia solution of urea at a temperature below the temperature of reaction between cellulose and urea, to cause distribution of the urea throughout the cellulose, removing the ammonia at a temperature below the temperature of reaction between cellulose and urea, thereby obtaining cellulose having urea distributed therethrough, and heating the thus obtained cellulose with urea distributed therethrough to a temperature sufficiently high to cause reaction between the cellulose and the urea, thus obtaining an alkali-soluble cellulose compound.
Claim 2
Independent Claim
93 words
A method of producing an alkali-soluble cellulose compound, which method comprises treating cellulose with a liquid ammonia solution of urea at a temperature below the temperature of reaction between cellulose and urea, to cause distribution of the urea throughout the cellulose, removing the ammonia at a temperature below the temperature of reaction between cellulose and urea, thereby obtaining cellulose having urea distributed therethrough, and heating the thus obtained cellulose with urea distributed therethrough to a temperature sufficiently high to cause reaction between the cellulose and the urea, thus obtaining an alkali-soluble cellulose compound.
Claim 3
Dependent Claim
22 words
A method according to claim 1, wherein the cellulose is treated with the liquid ammonia urea solution at a temperature below -33°C.
Claim 4
Dependent Claim
30 words
A method according to claim 1, wherein the cellulose is treated with the liquid ammonia urea solution under pressure at a temperature higher than the boiling point of the ammonia.
Claim 5
Independent Claim
25 words
A method according to any preceding claim, wherein the quantity of urea is between 20 and 120% by weight of the weight of the cellulose.
Claim 6
Independent Claim
15 words
A method according to any preceding claim, wherein 05 the ammonia is removed by evaporation.
Claim 7
Independent Claim
26 words
A method according to any'preceding claim, wherein the cellulose having the urea distributed therethrough is heated to a reaction temperature of between about 110 and 150°C.
Claim 8
Dependent Claim
14 words
A method according to claim 6, wherein the reaction is effected at subatmospheric pressure.
Claim 9
Independent Claim
26 words
A method according to any preceding claim, wherein the product alkali-soluble cellulose compound is washed with liquid ammonia at a temperature between about -40°C and +30°C.
References Cited (Backward Citations)
No citation records indexed.
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