Epoxy resin stilbenes and process for producing the same by photoisomerization
AssigneeSumitomo Chemical Company, Limited
InventorsAkira Yokota, Yasuhiro Hirano, Masatsugu Akiba, Hiroshi Nakamura, Shigeki Naitoh
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Abstract
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.
Claims10
A process comprising the step of photoisomerizing an epoxy resin containing stilbene linkages, wherein said photoisomerization results in a cis-isomer content in the epoxy resin of at least about 10% by mole.
A process comprising the steps of:
- photoisomerizing a phenolic stilbene compound to yield an isomerized phenolic stilbene compound, wherein said photoisomerization results in a cis-isomer content of at least about 10% by mole, or in the alternative, about 100% by mole, and
- converting said isomerized phenolic stilbene compound to an epoxy resin by reaction with epihalohydrin in the presence of a base.
A process for producing a stilbene epoxy resin comprising the step of irradiating with ultraviolet light a trans-stilbene epoxy resin represented by the general formula 2:
- ##STR9## wherein R.sub.1 to R.sub.8 independently represent an acyclic or cyclic alkyl group, a hydrogen atom or a halogen atom.
A process for producing an epoxy resin comprising the steps of:
- (i) irradiating with ultraviolet light a trans-stilbene phenol represented by the general formula (3):
- ##STR10## wherein R.sub.1 to R.sub.8 independently represent an acyclic or cyclic alkyl group, a hydrogen atom or a halogen atom,
- to yield a stilbene phenol represented by formula (4):
- ##STR11## wherein R.sub.1 to R.sub.8 independently represent an acyclic or cyclic alkyl group, a hydrogen atom or a halogen atom;
- and
- (ii) reacting said stilbene phenol represented by formula (4) with epihalohydrin in the presence of a base.
Dependencies are inferred from the claim text.