Benzenesulfonic acid

Benzenesulfonic acid (CAS 98-11-3), also known as phenylsulfonic acid, is a strong aromatic sulfonic acid used industrially as a catalyst, pH regulator, and intermediate in the synthesis of dyes, pigments, and surface-active agents.

Where is Benzenesulfonic acid used?

• Dye and pigment manufacturing: sulfonation intermediate and coupling agent
• Textile and leather processing: pH control during dyeing and tanning
• Coatings and resins: acid catalyst for curing in baking enamels and crosslinked polymer formulations
• Printing inks: dispersing aid that stabilizes pigment suspensions and improves press flow
• It influences color yield and batch consistency during production.

Commercial specifications

• Aqueous solution, most commonly 65–70%
• Higher-purity grades for catalyst and specialty applications, with consistent acid content and low impurity profiles