Use of a treated, promoted ion exchange resin catalyst
View Patent ↗The present invention relates to the use of an antioxidant treated promoted strong acid ion exchange resin as an acid catalyst.
1. A process for producing dihydric phenol 2,2bis(4′-hydroxyphenyl) propane comprising condensing phenol with acetone in the presence of an acid catalyst to produce dihydric phenol 2,2bis(4′-hydroxyphenyl) propane;
wherein the acid catalyst is a promoted ion exchange resin catalyst contacted with an antioxidant to produce a treated promoted ion exchange resin catalyst.
2. The process of claim 1 wherein the ion exchange resin catalyst is a sulfonic acid-type cation-exchange resin catalyst.
3. The process of claim 2 wherein the cation-exchange resin catalyst is a sulfonated styrene-divinyl benzene copolymer.
4. The process of claim 1 wherein the antioxidant is a monocyclic or polycyclic phenol, an amine, a diamine, a thioester, a phosphate, a quinoline, or a mixture thereof.
5. The process of claim 1 wherein the antioxidant is 2,6-di-t-butyl-.alpha.-dimethylamino-p-cresol.
6. The process of claim 1 wherein the amount of antioxidant incorporated into the cation-exchange resin catalyst is from 0.001 to 10 percent by weight.
7. The process of claim 1 wherein the ratio of phenol to acetone is 2:1.