Protection of lyocell fibres against fibrillation; Mode of action of the cross‐linking agent 2,4‐dichloro‐6‐(β‐sulphatoethylsulphonyl)anilino‐s‐triazine

2,4‐Dichloro‐6‐(β‐sulphatoethylsulphonyl)anilino‐ s ‐triazine is used as a cross‐linking agent to improve the wet abrasion resistance of Lyocell fibres. The agent, which exhibits poor water solubility, is sold as an aqueous dispersion. During application to Lyocell in the presence of alkali, the agent enters a solution phase before reacting with the fibres. High pressure liquid chromatography analysis and solution studies support the view that the two electrophilic species taking part in the cross‐linking reaction are vinylsulphone plus one of the chlorine atoms of the dichlorotriazine residue and that preliminary hydrolysis of one of the chlorine atoms is not the cause of the observed solubility changes.