Solvent system for cellulose
AssigneeInternational Telephone and Telegraph Corporation
InventorsAlbin F. Turbak, Adel El-Kafrawy, Fred W. Snyder, Jr., Andrew B. Auerbach
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Abstract
Cellulose is activated by penetration of the cellulose with a polar medium and mixed at a temperature at which no significant degradation occurs with an amide selected from the group consisting of dimethylacetamide, 1-methyl-2-pyrrolidinone and mixtures thereof and from 3 to 15% by weight of lithium chloride. The cellulose is then dissolved in the amide and lithium chloride in the substantial absence of any polar medium other than the amide. Shaped cellulosic products may be formed by reconstituting the cellulose in fiber, sheet or other form.
Claims24
A process of dissolving cellulose comprising
- mixing activated cellulose at a temperature at which no significant degradation occurs with an amide selected from the group consisting of dimethylacetamide, 1-methyl-2-pyrrolidinone and mixtures thereof and from 3 to 12% by weight of the solution of lithium chloride and
- dissolving said cellulose without significant degradation thereof in said amide and lithium chloride in the substantial absence of any polar medium other than the amide.
A process of dissolving cellulose comprising
- adding at a temperature at which no significant degradation occurs activated cellulose to an amide selected from the group consisting of dimethylacetamide, 1-methyl-2-pyrrolidinone and mixtures thereof and from 3 to 12% by weight of the solution of lithium chloride and
- dissolving said cellulose without significant degradation thereof in said amide and lithium chloride in the substantial absence of any polar medium other than the amide.
A process for dissolving cellulose comprising
- activating cellulose by penetrating the cellulose with a polar medium which swells the cellulose,
- adding at a temperature at which no significant degradation of the cellulose occurs up to 16% by weight of said activated cellulose to an amide selected from the group consisting of dimethylacetamide, 1-methyl-2-pyrrolidinone and mixtures thereof and from 3 to 15% by weight of the solution of lithium chloride and
- stirring said mixture to form a solution of the cellulose in said amide and lithium chloride.
A process of dissolving cellulose to form a solution of cellulose in a solvent comprising
- adding at a temperature at which no significant degradation occurs cellulose to a solution containing an amide selected from the group consisting of dimethylacetamide, 1-methyl-2-pyrrolidinone and mixtures thereof, from 3 to 15% by weight of lithium chloride and water,
- evaporating the water from said solution until the solution contains less than 5% by weight of water and
- dissolving the cellulose in said solution.
A cellulosic solution containing cellulose, from 3-15% by weight of the solution of lithium chloride and an amide selected from the group consisting of dimethylacetamide and 1-methyl-2-pyrrolidinone.
A process of dissolving cellulose comprising
- mixing activated cellulose at a temperature at which no significant degradation occurs with an amide selected from the group consisting of dimethylacetamide, 1-methyl-2-pyrrolidinone and mixtures thereof and from 3 to 15% by weight of the solution of lithium chloride and
- dissolving said cellulose without significant degradation thereof in said amide and lithium chloride.
Dependencies are inferred from the claim text.