p-toluenesulfonic acid

p-Toluenesulfonic acid (CAS 104-15-4), commonly known as tosic acid or pTSA, is a strong organic acid used primarily as an acid catalyst and pH regulator in industrial manufacturing.

Where is p-toluenesulfonic acid used?

• Coatings and thermoset systems: curing catalyst for amino and phenolic resins, accelerating crosslinking in baked enamel and industrial coating formulations
• Polymers and adhesives: catalyst for esterification, condensation and polymerization
• Textile and leather processing: dye fixation and pH regulation during finishing
• Printing inks: dispersing aid and stabilizer
• Its high solubility in organic solvents makes it a practical alternative to mineral acids where aqueous conditions are undesirable.

Good to know: The monohydrate form is the most common commercial grade due to its handling stability.

Commercial specifications

• High-purity grades meeting defined specifications for tighter quality control