Polysaccharide fibers and method for producing same
View Patent ↗The present invention relates to a direct dissolving process for the production of polysaccharide fibers which contain α(1→3)-glucan as a fiber-forming substance, with aqueous sodium hydroxide solution as a solvent, as well as to the fibers made thereby, and to their use.
1. A method for the production of a polysaccharide fiber whose fiber-forming substance is α(1→3)-glucan, wherein the method is a direct dissolving process which comprises the step of spinning the fiber by extruding a spinning solution comprising between 4.5% and 12% by weight of the fiber forming substance and an aqueous sodium hydroxide solution, wherein the spinning occurs in a spin bath comprising sulfuric acid, and wherein a spun fiber is formed.
2. The method according to claim 1 , wherein the aqueous sodium hydroxide solution concentration in the spinning solution is between 4.0 and 5.5% by weight related to the total quantity of the spinning solution.
3. The method according to claim 1 , wherein the spin bath comprises H 2 SO 4 in a concentration between 200 and 500 g/l.
4. The method according to claim 1 , wherein the spin bath comprises H 2 SO 4 in a concentration between 20 and 60 g/l.
5. The method according to claim 1 , wherein the spun fiber is subsequently stretched in an acid regeneration bath.
6. The method according to claim 1 , wherein at least 90% of the α(1→3)-glucan are hexose units and at least 50% of the hexose units are linked via α(1→3)-glycosidic bonds.
7. The method according to claim 1 , 2 , 3 , 4 , 5 , or 6 , wherein the fiber is selected from the group consisting of a staple fiber and a continuous filament.