Condensation : Bisphenol A (BPA)

Condensation : Bisphenol A

Bisphenol A (BPA) is primarily used for polycarbonate and epoxy resins. The main driver for BPA is the demand of Polycarbonate. In 2002 an estimated production value of USD 2.5 billion was achieved. Polycarbonates are an unusual and extremely useful class of polymers and sold under a variety of trade names. Polycarbonate resin is used in automotive components, glazing sheet and optical media such as CD and DVD. Epoxy resins are used in protective coatings, electrical laminates and encapsulations, bonding and adhesives, glass fiber-reinforced materials.

Bisphenol A (BPA) is produced by condensation of phenol and acetone in the presence of HCl or sulphonated styrene DVB catalysts such as the industry standard Amberlyst™ 31Wet, or higher performing monodisperse catalysts like Amberlyst™ 121Wet, 131Wet and 232Wet. Most recently introduced Amberlyst™ 33, was designed to meet the stringent demands of Bisphenol A (BPA) production, coupling high activity with even lower acid and leaching.

The reaction is acid catalyzed at 60-80°C with a molar ratio of phenol to acetone ranging from 3:1 to 10:1. The condensation reaction gives a mixture of BPA and its isomer o,p-BPA and small amounts of impurities including trisphenol, polyphenols and the Dianin compound isomers. The latter impurities are formed by the reaction of phenol with trace amounts of mesityl oxide which itself is a product of self-condensation of acetone followed by dehydration.

The HCl catalyzed process gives higher acetone conversion but gives relatively lower yield of BPA due to the decomposition of BPA during distillation in the presence of acids. The traditional route also requires corrosion resistant materials in contact with process streams and extensive facilities for recovery of the catalyst and for purification of the BPA product.
Because of its high performance, excellent BPA quality, its lack of corrosivity and its safety and ease of handling, the Amberlyst™ catalyzed process is now used by all the major BPA producers.

Recommended Catalysts:

	Amberlyst™ 31Wet	Conventional grade catalyst suitable for all reactor designs with excellent lifetime and conversion rate.
	Amberlyst™ 33	Low leaching sulfonic acid polymer catalyst.
	Amberlyst™ 131Wet	Monodisperse catalyst which confers enhanced hydraulic and reactivity properties compared to conventional catalysts.
	Amberlyst™ 121Wet Amberlyst™ 232Wet	Uniform particle size catalysts with an excellent resistance to organic fouling and a prolonged life.

Amberlyst catalysts for BPA are approved by all major BPA producers. Rohm and Haas has a long standing experience in the catalysis of BPA.

For sampling, pricing, availability or more information about our AMBERLYSTT catalysts please contact your Rohm and Haas represenative.