US Patent 7989514 Strong-acid cation exchange resins

A strong-acid cation exchange resin comprising a plurality of acid groups which are partially neutralized with a cation of formula (I); wherein R1 at each occurrence independently is hydrogen or a Ci-4-alkyl group, R2 at each occurrence independently is hydrogen, alkyl or aryl, R3 at each occurrence independently is hydrogen or alkyl or two vicinal groups R3 together form an aromatic ring, m is 1, 2, 3, 4, 5 or 6, n is 1, 2, 3 or 4, o is 1 or 2, and p is 1, 2 or 3, is useful in the production of bisphenols.