Rayon fibers containing starch

Claim 2

chain-splitting agent comprises hydrogen peroxide. 11. Process as in claim 10 in which the concentration of H 2 O 2 is at least 0.01% based

Claim 3

on the weight of water. 12. Process as in claim .[.9.]. .Iadd.29 .Iaddend.in which the proportion of chain-splitting agent is such as to produce the alkaline starch solution having a concentration of 14 to 20% starch and a viscosity of about 35-170 poises, said viscosity being lower than that of a corresponding starch solution which has not been subjected to said chain-splitting agent. .[.13. Process for preparing starch-containing rayon fibers which comprises dissolving corn starch granules in an aqueous alkaline medium which contains between 2 and 41/2% NaOH based on the total weight of water and NaOH, the concentration of starch in the resulting solution being about 6 to 20%, and blending said solution with viscose and extruding the starch-containing viscose in fiber form and regenerating the cellulose in the extruded viscose to form starch-containing regenerated cellulose fibers, said starch having an

Claim 4

amylopectin content of at least 60 percent..]. 14. Process for producing rayon fibers which comprises extruding a viscose solution, containing about 5 to 25% dissolved starch b.o.c., to form a plastic stretchable fiber and then stretching said plastic fiber at least 50% to form fibers having a tenacity of at least about 2 grams per denier.[., said starch

Claim 5

having an amylopectin content of at least 60 percent.].. 15. Process as in claims 14 in which said viscose solution is extruded into an aqueous coagulating bath containing H 2 SO 4 and at least 0.5% ZnSO 4

Claim 6

and is stretched at a temperature about 70° C. 16. Process as in claim 15 in which said coagulating bath containing about 6-13% H 2

Claim 7

SO 4 about 0.5-5% ZnSO 4 and about 12-25% Na 2 SO 4 .

Claim 8

Product of the process of claim 14. 18. Process as in claim 14 in which the viscose contains a regeneration retarder, the stretching is at

Claim 9

least 100% and the resulting fiber has a wet modulus above 7. 19. Product

Claim 10

of the process of claim 18. 20. Process as in claim 15 in which the stretching conditions are such as to produce coagulated regenerated filaments having a skin and a partly exposed core and the stretched filaments are cut into staple fibers and then relaxed to form crimped

Claim 11

fibers. 21. Product of the process of claim 20. 22. Process .Iadd.as in claim 29 .Iaddend.which comprises extruding in fiber form a viscose containing about 5 to 100% dissolved starch b.o.c. and an anionic polymer dispersed in said viscose and coagulating the extruded solution to form fibers containing dispersed anionic polymer and having an increased fluid holding capacity because of the presence of said anionic polymer.[., said

Claim 12

starch having an amylopectin content of at least 60 percent.].. 23. Process as in claim 22 in which the amount of said anionic polymer

Claim 13

dispersed in said viscose is at least about 10% b.o.c. 24. Product of the

Claim 14

process of claim 22. 25. Process as in claim 23 in which said anionic polymer has at least about 0.2 gram equivalent of salt forming anionic

Claim 15

groups per 100 grams. 26. Process as in claim 25 in which said anionic

Claim 16

polymer comprises a sodium polyacrylate. 27. Process as in claim 25 in

Claim 17

which said anionic polymer comprises sodium carboxymethyl cellulose. 28. Process .Iadd.as in claim 29 .Iaddend.which comprises extruding in fiber form a viscose containing about 5 to 100% dissolved starch b.o.c. and polyvinylpyrollidone and coagulating the extruded solution to form fibers having increased fluid holding capacity because of the presence of said polyvinylpyrollidone.[., said starch having an amylopectin content of at least 60 percent.].. .Iadd. 29. Process for preparing starch-containing rayon fiber which comprises forming a slurry of starch granules in aqueous medium, adding an aqueous solution of a starch-splitting agent active in alkaline medium to said slurry, the proportion being about 0.003 by 0.015 moles of agent per mole of starch in slurry, adding sodium hyroxide (NaOH) to said slurry to produce an aqueous alkaline solution of starch, blending said solution with viscose, extruding the starch-containing viscose in fiber form and regenerating the cellulose in the extruded viscose to form starch-containing regenerated cellulose fibers, said starch having an amylopectin content of at least 60%. .Iaddend.