Production of epoxy resins using improved ion exchange resin catalysts
View Patent ↗Use a modified, amine-functionalized anion exchange resin as a catalyst to produce a bishalohydrin ether and then dehydrohalogenate the bishalohydrin ether with an aqueous inorganic hydroxide mixture to yield a liquid epoxy resin.
1. An improved process for producing a liquid epoxy resin by etherifying a polyhydric phenol and an epihalohydrin with an amine-functionalized anion exchange resin as a catalyst to produce a bishalohydrin ether and dehydrohalogenating the bishalohydrin ether with an aqueous inorganic hydroxide mixture, the bishalohydrin ether optionally being in admixture with an organic solvent, wherein the improvement comprises using a modified amine-functionalized anion exchange resin as an etherification catalyst, the modified amine-functionalized anion exchange resin having at least one of a) a polymerized crosslinking monomer content within a range of from 0.1 percent by weight to 4 percent by weight, each percent by weight being based upon total weight of the monomers used to prepare the anion exchange resin copolymer, b) an average particle size within a range of from 10 micrometers to 200 micrometers (with size determination based on wet resin), c) a degree of functionalization such that from 2 percent to 60 percent of monomer units in the modified amine-functionalized anion exchange resin are functionalized, and d) functionalization with quaternary ammonium groups represented by a formula —NR 3 + X − wherein each R is independently an alkyl group or an alkoxy group having at least two carbon atoms and wherein X is an anion selected from the group consisting of a halogen, a hydroxide, a carboxylate, a carbonate, and a sulfate.
2. The process of claim 1 , wherein the crosslinking monomer is selected from a group consisting of polyvinylidene aromatics, alkylene diacrylates and alkylene dimethacrylates.
3. The process of claim 1 , wherein the crosslinking monomer is a polyvinylidene aromatic selected from a group consisting of divinylbenzene, divinyltoluene, divinylxylene, divinylnaphthalene, trivinylbenzene, bis(vinylphenyl)alkanes, divinyldiphenylsulfone.
4. The process of claim 1 , wherein the crosslinking monomer is divinylbenzene.
5. The process of claim 1 , wherein each R has no more than eight carbon atoms.
6. The process of claim 1 , wherein the modified amine-functionalized anion exchange resin has a dry weight capacity of 3.5 meq/g or less.
7. The process of claim 1 , wherein the polyhydric phenol is Bisphenol A and the epihalohydrin is epichlorohydrin.