Our range of dyes to the paper industry includes anionic direct dyes and basic dyes.
Tradename direct dyes: Trupocor
Anionic direct paper dyes contain several sulfonic or carboxyl groups to activate the dye soluble in water. In solution the dyes are dissociated into a dye anion and a colorless cation. The dye molecules also exhibit a linear and planar structure, which allows the dye to attach to the cellulose chains in the fiber via intermolecular bonding. They have good substantivity on sized and unsized paper and bleached, unbleached and mechanical pulp. In most cases the use of a fixing aid is suggested.
Direct dyes give low colored waste water and good fastness to water, steam and light.
Tradename basic dyes: Trupobase
In basic paper dyes, the part of the molecule responsible for its color (i.e., the chromophore) is present as a cation. Paper coloration is achieved by ionic bonding between cations and negatively charged compounds in the fiber. As a result, basic dyes are most efficient in lignin containing furnishes such as those prepared from mechanical pulp.
Basic dyes offer a number of desirable properties:
- They are cost-effective colorants that produce brilliant shades
- They offer sufficient light fastness and good water fastness
- They represent a large family of colors spanning reds, yellows and blues