Sustainable range of sulfur dyes for textile and paper dyeing
AssigneeClariant International Ltd.
InventorsManuel Jose Domingo, Joan Manel Blanquera, Yolanda Garcia
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Abstract
The invention refers to the manufacturing of a novel group of sulfur dyes in which are used, as raw material, different kind of natural “biomass”, usually existing in the nature, and transforming them into soluble dyestuffs, capable to dye textile fibers, preferably cellulose fibers and derivatives, as cotton, viscose, paper, tencel, with high strength and fast color properties. For this purpose, the concept “Biomass”, is defined as the residual product obtained from the usual human crop activities, in agricultural and forestry sectors.
Claims20
A process for manufacturing a dyestuff comprising:
- (i) providing vegetal biomass;
- (ii) pretreating said vegetal biomass with an aqueous acidic medium;
- (iii) neutralizing pretreated vegetal biomass and/or isolating pretreated vegetal biomass in form of a presscake;
- (iv) mixing pretreated vegetal biomass in (iii) with at least one sulfurization agent selected from the group consisting of sulfur, sulfide, and polysulfide to form a mixture;
- (v) heating said mixture to a temperature of from 120° C. to 350° C. for at least 2 hours;
- and
- (vi) dissolving the mixture in aqueous medium and optionally removing undissolved solid particles.
Dependencies are inferred from the claim text.