摘要 |
<p>Halogenated aromatic epoxy resins wherein the halogen atoms are in the meta position with respect to a glycidyl ether group attached to an aromatic ring. Advanced epoxy resins are disclosed which result from the reaction of a relatively low molecular weight epoxy resin and a polyhydric phenol wherein at least one of the reactants contains at least one halogen atom which is meta with respect to a glycidyl ether group or a hydroxyl group attached to an aromatic ring. These advanced epoxy resins, when cured with a suitable curing agent, possess an improvement as compared to an advanced epoxy resin containing halogen atoms which are ortho with respect to a glycidyl ether group in at least one of thermal stability, glass transition temperature, relationship of viscosity to molecular weight and resistance to forming hydrolyzed halides in the presence of a refluxing solution of an alkali metal hydroxide.</p> |