Colorimetric Characterization of Leather Assortments Finished with Ecologic Materials

Leather is finished by coating the dermal substrate with disperse finishing systems containing: pigments, binders, natural and synthetic waxes, preservatives, plasticizers, thickeners, fillers, odorizers, penetrating agents, solvents. To prepare the pigment pastes, black iron oxide pigments were used – admitted by the legislation in force, Bindex BRILLANT acrylic binder as carrier resin – also having protective colloid properties, lauryl alcohol ethoxylated with 7 moles of ethylene oxide – fully biodegradable – as a dispersing agent and stabilizer and natural oils as plasticizers: castor oil, flax oil or poppy seed oil. The pigment pastes to be used in the final dressing for the dry finishing of natural leather. In this paper, a finishing composition, technology for leather assortments and characterization by CIE L*a*b* colorimetric method are presented. After thermal and artificial light aging, the colorimetric characteristics (CIE L*a*b*) change, depending on the temperature of the heat treatment and UV light, leather assortment, and type of final dressing. The highest resistance to light after aging under the influence of artificial light has the leathers finished with polyurethane or acrylic dressing in comparison with those finished with nitrocellulose dressing.