Dye-capturing non-woven fabric and method for producing the same
The present invention relates to a method for producing a dye-capturing non-woven fabric, the method comprising the steps of providing a non-woven substrate and applying a composition to the non-woven substrate, the composition having binding and dye-capturing functionalities. The present invention further relates to a dye-capturing non-woven fabric obtainable by such a method and a dye-capturing non-woven fabric comprising a non-woven substrate comprising cellulose fibers and a dye-capturing agent adhering to the non-woven substrate by means of a binder and/or a dye-capturing agent being absorbed in the non-woven substrate.
1. A method for producing a dye-capturing non-woven fabric, the method comprising the steps of:
providing a non-woven substrate;
applying a composition to the non-woven substrate, the composition having binding and dye-capturing functionalities and comprising:
a binder, wherein the binder comprises polyamido-amine epichlorohydrin (PAAE);
a dye-capturing agent having a cationic functional group; and
at least one of an acid or a salt thereof;
stabilizing a charge of the cationic functional group using the binder to obtain a stabilized cationic charge;
activating the stabilized cationic charge with the at least one of an acid or a salt thereof to obtain an activated charged adduct of the binder, the dye-capturing agent and the at least one of an acid or a salt thereof; and
immobilizing the activated charged adduct at the non-woven substrate.
2. The method according to claim 1 , wherein the step of providing a non-woven substrate comprises forming a non-woven substrate by at least one process selected from the group consisting of a wet-laid, an air-laid, a spunlace and a spunbond process.
3. The method according to claim 1 , wherein the composition is applied during manufacture of the non-woven substrate.
4. The method according to claim 1 , wherein the dye-capturing agent is selected from the group consisting of copolymers of vinylimidazole and vinylpyrrolidone, copolymers of vinylimidazole and vinylcarbazole, copolymers of vinylimidazole and vinylphthalimide, and copolymers of vinylimidazole and vinylindole.
5. The method according to claim 1 , wherein the acid is an organic acid.
6. The method according to claim 1 , wherein the composition comprises polyamido-amine epichlorohydrin (PAAE), a copolymer of vinylimidazole and vinylpyrrolidone and citric acid.
7. The method according to claim 1 , further comprising a step of treating the dye-capturing non-woven fabric with a cationising agent.
8. The method according to claim 1 , wherein the composition has a pH value adjusted by addition of the at least one of an acid or a salt thereof in a range of 2 to 7.
9. The method according to claim 1 , wherein the composition has a pH value adjusted by addition of the at least one of an acid or a salt thereof in a range of 2 to 6.