Ludigol (Sodium 3-Nitrobenzenesulfonate)

Basic Information

Textile Industry:
- Prevents reduction of reactive and disperse dyes during steaming
- Used in re-oxidation of vat dyes
- Essential for monochlorotriazine dyes (Procion H type)
- Improves brightness in dark shades and silk dyeing
Industrial Uses:
- Auxiliary agent in electronics, photography, and coating industries
- Brightness enhancer in electroplating baths
Laboratory Use:
- Reagent in synthesis of azetidinyl ketolides (antibiotic intermediates)

Alternative Product	Description	Application
Sodium Nitrite (NaNO₂)	Mild oxidizer	Anti-reducing agent in textile dyeing
Sodium Perborate	Oxidizer, bleaching agent	Color fixation in reactive dyes
Sodium Persulfate (Na₂S₂O₈)	Strong oxidizer	Post-printing and dye fixation
Resist Salt / Resist S	Commercial equivalent	Anti-reducing agent in reactive dyes
Ludigol F / Ludigol KN	BASF variants	Steam fixation, dark shade protection
Nitrol S / Nacan / Tiskan	Same chemical structure	Marketed under different brands

Typical dosage: 10 g/kg
Purpose:
- Prevents dye solution degradation
- Keeps dye solutions fresh for longer
- Ensures sharper edges in printed fabrics
- Enhances brightness and stability, especially in dark tones and silk

Sector	Application	Benefit / Function
Textile	Reactive & disperse dyeing, steaming, vat dye re-oxidation	Prevents dye reduction, enhances brightness, sharper print edges, essential for Procion H dyes
Silk & Dark Shades	Dye fixation during steaming	Maintains deep tones, prevents dullness, improves color vibrancy
Leather	Dyeing and finishing processes	Stabilizes colors, prevents fading during curing
Paper	Dyeing and coating	Improves color fastness and brightness
Electronics	Electroplating baths	Acts as brightness enhancer, stabilizes bath chemistry
Photography	Auxiliary chemical in developing processes	Controls reduction reactions, improves image clarity
Coatings	Industrial coatings and paints	Ensures uniform color fixation, prevents unwanted reduction
Laboratory / Pharma	Intermediate in synthesis (e.g., azetidinyl ketolides)	Functions as a reagent in advanced chemical synthesis

Key Notes:

Dosage: Typically 10 g/kg in textile applications.
Critical Use: Required for monochlorotriazine dyes (Procion H type) during steaming.
Optional Use: For dichlorotriazine (Procion MX) and monofluorotriazine (Cibacron F) dyes, beneficial but not strictly necessary.
Alternatives: Sodium nitrite, sodium perborate, sodium persulfate, Resist Salt/S, Ludigol F/KN (BASF variants).