Patent ID: 7108907
Filing Date: 2006-09-19
Classification: C08B,D01F,Y10T

Abstract:
1. A cellulose dope comprising an aqueous sodium hydroxide solution and cellulose dissolved in said solution, said cellulose dope having a sodium hydroxide concentration (C wherein a zero-shear viscosity (η wherein: η Cc represents the cellulose content (% by weight) of the cellulose dope, DPc represents the viscosity average degree of polymerization of the cellulose in the cellulose dope, k=3.9×10 m is a number of from 6.3 to 6.5, and p is a number of from 3.2 to 3.5, said cellulose dope being produced by a method which comprises: (1) providing a cellulose slurry comprising an aqueous sodium hydroxide solution and, dispersed therein, particulate cellulose having an average particle diameter of 30 μm or less, said cellulose slurry being achieved by wet pulverization in a stirred medium wet grinding apparatus, and having a sodium hydroxide concentration of from 0.5 to less than 6.5% by weight and a cellulose content of 5% by weight or more, (2) adjusting the sodium hydroxide concentration of the cellulose slurry to 6.5 to 11% by weight, and (3) stirring the cellulose slurry at 10° C. or less by means of a stirrer under stirring conditions satisfying at least one requirement selected from the group consisting of the requirement that the stirring is performed at a shear rate of 9,000/sec or less and the requirement that the stirring is performed at a stirring speed of 500 m/min or less in terms of the speed at which the outer end of an agitating element of the stirrer is rotated, said steps (2) and (3) being conducted in the order of step (2) and step (3) or simultaneously, thereby causing the particulate cellulose to be dissolved in the cellulose slurry to the extent that the cellulose has a dissolution ratio (Sc) of 99.0% by weight or more, to obtain a cellulose dope, wherein said cellulose slurry satisfies the following formula (2): wherein: σ K k C wherein, in the solid state NMR analysis of said slurry, the cellulose in said slurry exhibits a non-crystallinity (χam) of 0.5 or more, said non-crystallinity being defined by the following formula (3): wherein: χam is the non-crystallinity of the cellulose in said slurry, and I