Epoxy resin stilbenes and process for producing the same by photoisomerization

摘要

The invention provides a cis-stilbene type epoxy resin having lower melting point and lower viscosity than the trans-stilbene type epoxy resin hitherto known. The stilbene type epoxy resin has a cis- isomer content of essentially 100%, or in the alternative, at least about 10% with the rest being the trans-isomer, and is based on the following general formula (1): ##STR1## wherein R.sub.1 to R.sub.8 are independently an acyclic or cyclic alkyl group, a hydrogen atom, or a halogen atom. Production processes for these epoxy resins are also disclosed.