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US 5,512,230 AGranted
Process for making cellulose acetate fibers
AssigneeEastman Chemical Company
InventorJesse N. Cannon, III
Life of this patent
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Abstract
A method for spinning a cellulose acetate fiber having a low degree of substitution per anhydroglucose unit (DS/AGU) of the cellulose acetate is provided. The addition of 5 to 40 weight percent water to cellulose acetate(CA)/acetone spinning solutions (dopes) will produce dopes that will allow fibers to be solvent spun using CA with a DS/AGU from 1.9 to 2.2.
Claims6
A method for the production of cellulose acetate fibers comprising
- (I) forming a solution consisting essentially of
- (a) about 10 to 40 weight percent, based on the total weight of (a), (b), and (c), of cellulose acetate having a DS/AGU of from 1.9 to 2.2;
- (b) about 20 to 85 weight percent, based on the total weight of (a), (b), and (c), of acetone;
- (c) about 5 to 40 weight percent, based on the total weight of (a), (b), and (c), of water;
- said solution having a zero shear viscosity at 29.degree. C. of about 100 to about 10,000 poise;
- (II) filtering said solution to form a spinning solution;
- followed by
- (III) spinning said spinning solution at a temperature of about 25.degree. C. to 95.degree. C., at 200 to 1,500 meter/min. through spinnerette holes having a hole area equivalent to a circular diameter of 20 to 100 microns and length to diameter ratio of 0.5 to 3, thereby forming a cellulose acetate fiber having a dry linear density of 0.5 to 20 denier per filament and a total product denier of from 10,000 to 100,000 denier.
5 more elements
Dependencies are inferred from the claim text.