Post-crosslinking treatment of cellulosic materials for enhanced dyeability
AssigneeThe United States of America as represented by the Secretary of Agriculture
InventorsEugene J. Blanchard, Robert M. Reinhardt
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Abstract
Anionically dyeable smooth-dry crosslinked cellulosic materials are produced by treatment of methylolamide crosslinked cellulosic materials with an alkali swelling agent such as sodium hydroxide prior to dyeing. Attainable color strength is dependent upon both the concentration and the contact time of the alkali swelling agent with the cellulosic material. Types of usable anionic dyes include acid, direct, and reactive dyes. The cellulose-containing material may be in the form of fibers, threads, linters, roving, fabrics, yarns, slivers and paper.
Claims29
A modified crosslinked cellulosic reaction product consisting of a crosslinked cellulosic reaction product comprising:
- a cellulosic substrate;
- a methylolamide crosslinking agent bound to said cellulose substrate, wherein said methylolamide crosslinking agent is supplied in a formulation concentration of about 3% to about 15% by weight;
- and one or more of a hydroxyalkylamine or a hydroxyalkyl quaternary ammonium compound chemically bound to said methylolamide crosslinking agent;
- wherein said crosslinked cellulosic reaction product which has been cured at a temperature range of about 100.degree. C. to about 220.degree. C. has been subsequently modified by contact for about 0.5 minutes to about 20 minutes with an aqueous solution containing an alkali agent is selected from the group consisting of alkali metal hydroxides and quaternary ammonium hydroxides in an amount of about 5% to about 30% by weight so as to expand the cellulosic fiber structure and make the material more amenable to anionic dyeing.
A process for subsequently modifying a crosslinked cellulosic material comprising contacting a cellulosic material which, has been crosslinked with a methylolamide crosslinking agent, present in a crosslinking formulation concentration of about 3% to about 15% by weight, in the presence of a salt of either a hydroxyalkylamine or a quaternary ammonium compound and subsequently cured at a temperature range of about 100.degree. C. to about 220.degree. C., with an aqueous alkali agent selected from the group consisting of alkali metal hydroxides and quaternary ammonium hydroxides and present in the solution in an amount of about 5% to about 30% by weight of said solution for a period of time sufficient to expand the cellulosic fiber structure and make the material more amenable to anionic dyeing.
Dependencies are inferred from the claim text.