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US-12624215-B2 - Cationic dyes and uses thereof

US12624215B2US 12624215 B2US12624215 B2US 12624215B2US-12624215-B2

Abstract

The present invention relates to new nanocellulose-based cationic dyes, to a process for their synthesis, and to their use in processes for dyeing fibers, such as textile fibers.

Inventors

  • Amira EROKH
  • Cleverton PIRIH
  • Elsa TUFENKJIAN

Assignees

  • EVER DYE

Dates

Publication Date
20260512
Application Date
20230111
Priority Date
20220112

Claims (16)

  1. 1 . A cationic dye comprising: nanocellulose, at least one cationic moiety covalently linked to the nanocellulose, and at least one colored moiety linked to the nanocellulose, wherein the colored moiety is iron oxide.
  2. 2 . The cationic dye according to claim 1 , wherein the cationic moiety is covalently linked to nanocellulose in C2 or C3 position(s) of at least one glucose moiety of said nanocellulose.
  3. 3 . The cationic dye according to claim 1 , wherein the colored moiety is linked with ionic or hydrogen bonds to nanocellulose in C6 position of at least one glucose moiety of said nanocellulose.
  4. 4 . The cationic dye according to claim 1 , wherein the nanocellulose is selected from the group consisting of cellulose nanofibers, cellulose nanocrystals, and any mixture thereof.
  5. 5 . The cationic dye according to claim 1 , wherein the at least one cationic moiety comprises a quaternized amine group.
  6. 6 . The cationic dye according to claim 5 , wherein the at least one cationic moiety is selected from the group consisting of a quaternized diamine moiety, a quaternized amino acid, a quaternized peptide and a quaternized protein.
  7. 7 . The cationic dye according to claim 1 , wherein the at least one cationic moiety and the at least one colored moiety are different moieties.
  8. 8 . A process for the synthesis of the cationic dye according to claim 1 , comprising the following steps: (i) Contacting nanocellulose with a colored moiety, or a precursor thereof, and (ii) Contacting nanocellulose with a cationic moiety, to obtain a cationic dye.
  9. 9 . A process for dyeing at least part of a fiber material, comprising the steps of: a) contacting at least part of the fiber material with a pretreatment agent, selected from the group consisting of an oxidant and a hydrolyzing agent, so as to obtain a pretreated fiber material, and b) contacting the pretreated fiber material obtained at step a) with at least one cationic dye according to claim 1 , to obtain a dyed fiber material.
  10. 10 . The process for dyeing at least part of a fiber material according to claim 9 , wherein the fiber material is a textile fiber material.
  11. 11 . The process for dyeing at least part of a fiber material according to claim 10 , wherein the textile fiber material is selected from the group consisting of a cotton fiber material, a polyester fiber material, a keratinic fiber material and a mixture thereof.
  12. 12 . The process for dyeing at least part of a fiber material according to claim 9 , wherein the oxidant is selected from the group consisting of ((2,2,6,6-tetramethylpiperidin-1-yl)oxy) (TEMPO), ((2,2,6,6-tetramethylpiperidin-1-yl)oxy) (TEMPO), in presence of iron, potassium hydrogenopersulfate, hydrogen peroxide, hydrogen peroxide in presence of iron, and sodium metabisulfite.
  13. 13 . The process for dyeing at least part of a fiber material according to claim 9 , wherein dyeing step b) is performed at a temperature ranging from 20° C. to 50° C.
  14. 14 . The process for dyeing at least part of a fiber material according to claim 9 , wherein the process further comprises, after step b), a step of: c) drying the dyed fiber material obtained at step b) at a temperature lower than 100° C.
  15. 15 . The cationic dye according to claim 1 , wherein the nanocellulose is cellulose nanocrystals.
  16. 16 . The cationic dye according to claim 1 , wherein the at least one cationic moiety comprises a quaternized primary amine group.

Description

This application is the § 371 U.S. National Stage of International Application No. PCT/EP2023/050579, filed 11 Jan. 2023, which claims the priority to European App. No. EP22305027.9, filed 12 Jan. 2022. FIELD OF INVENTION The present invention relates to new nanocellulose-based cationic dyes, to a process for their synthesis, and to their use in processes for dyeing fibers, in particular textile fibers. BACKGROUND OF INVENTION The growth of human population and the current way of life have created an increasing demand for the consumption of clothing, amplifying the needs of textile dyeing. Textile dyeing processes are generally energy-consuming, requiring long reaction times and/or the use of high temperatures, and create massive and often toxic effluents. Dyeing of cotton fibers has been mainly performed over the past decades with reactive dyes, because such dyes are cost-effective and produce a wide range of colors. These dyes typically comprise aromatic chromophores and amine auxochromes, which give the color properties of the dye. They further comprise reactive groups, such as chlorine leaving groups, which afford linking the dye to the fabric surface via covalent bonds. Reactive dyes offer a very strong dye-textile fixation and excellent dyeing properties. However, chlorine ions are released during the chemical reaction, resulting in chloride-containing wastewater and colored sewage. In addition, reactive dyeing requires high thermal energy and pretreatment with salt saturated solutions to suppress the repulsive forces between the negatively charged dye molecules and cotton fibers. Electrolytes, such as sodium chloride, sodium carbonate and sodium sulphate, are added to the dyeing bath to improve the interactions between the dye and the fabric. Electrolyte concentrations are increased gradually to promote dye exhaustion which produce highly concentrated wastewater with a COD value equal to 50,000 ppm. Mordant dyes may also be used for dyeing cotton fibers. Natural dyes, also referred to as direct dyes, are derived from natural sources as animals and plants, hence they are more environmentally friendly than reactive dyes. However, they do not form strong covalent bond with cotton surfaces. They bind to the cellulosic fiber via electrostatic bonds, weak Van der Waals forces and/or hydrogen bonds. To increase the affinity of natural dyes, metal mordants are used as a dyeing pretreatment. Mordants bind to the fabric and to the dye by strong coordination bonds, thus fixing the dye molecules to the fabric surface. Previously, toxic chromium, iodine, cobalt and/or nickel complexes were used as mordants. Recently, metals with lower toxicity such as copper, iron, and aluminum are adopted as a greener pretreatment product. However, the problem of excessive metals concentration in wastewater and the enormous volume of water needed persists. Natural bio-mordants could also be used as a green replacement for metal mordants. For example, whey protein, a mixture of three proteins of bovine serum albumin, was used to improve the affinity of pomegranate natural dye toward cotton via hydrogen bonds and to decrease negative charges repulsive forces between fabric and dye molecules. Unfortunately, such products are not widely used in industry because of their cost of production. A few processes aiming at reducing the environmental impact of cotton fiber dyeing processes have been developed in the recent years. Anuradhi Liyanapathiranage et al. “Nanocellulose-based sustainable dyeing of cotton textiles with minimized water pollution” ACS Omega 2020, 5, 16, p. 9196-9203 disclose a dyeing process of cotton fibers using reactive dyes incorporated onto pristine nanocellulose fibers containing hemicellulose. The dying process is performed at 60° C. for 90 min, and a salt is used to create an affinity between the dye and the fiber. To further improve the fixation and lower the hydrophilic character, a post-treatment with polycarboxylic acids such as citric acid or maleic acid is performed, implying a soaking of the fabric in the solution and a drying step at a high temperature of 120° C. Smriti et al. “Environment-friendly nanocellulose-indigo dyeing of textiles” Green Chem. 2021, 23, p. 7937 disclose a dyeing process of cotton fibers involving a dye comprising natural indigo incorporated on nanocellulose fibers. The nanocellulose fibers dispersion is mixed with agglomerated indigo and a surfactant, Triton® X-100. The obtained suspension is mixed with cotton fibers, and a drying step is performed at 120° C. In order for the dyeing to resist washing of the cotton fabrics, a post-treatment involving chitosan solution adsorption is necessary. Said post-treatment is performed by soaking the dyed cotton fabrics with chitosan for 15 minutes, followed by a drying step performed at 120° C. CN113914124 discloses a modified nanocellulose and its use for the preparation of base paper with improved mechanical properties. The modified nanoce