Abstract: Co-advanced epoxy resins prepared by the reaction of polyethers of polyhydric phenols, diglycidyl ethers of di-secondary alcohols and dihydric phenols, said co-advanced resins being heat curable with suitable curing agents to afford cured coating compositions exhibiting a variety of excellent physical properties and performance characteristics.The diglycidyl ethers have the following formula: ##STR1## as defined in the specification.

Abstract: Advanced epoxy resins prepared by the reaction of diglycidyl ethers of di-secondary alcohols and dihydric phenols, said advanced resins being heat curable with suitable curing agents to afford cured coating compositions exhibiting a variety of excellent physical properties and performance characteristics.

Abstract: A co-initiator for use in an improved photopolymerization composition, element and method is disclosed. The photopolymerizaton composition comprises an addition-polymerizable compound containing ethylenic unsaturation and the co-initiator which includes a photopolymerization activator and an amine-substituted ketocoumarin sensitizer having an absorption maximum between about 350 and about 550 nm; said activator having the structure ##STR1## wherein Q.sup.1 and Q.sup.2 are each independently hydrogen; alkyl, thioalkyl or alkoxy containing from 1 to about 5 carbon atoms; aryl or aryloxy or benzoyloxy containing from about 6 to 10 carbon atoms; hydroxy; or halogen; or together Q.sup.1 or Q.sup.2 are the necessary atoms to complete a fused heterocyclic or aromatic ring containing from about 4 to 6 ring atoms; and Q.sup.3 is hydrogen or alkyl containing from 1 to about 5 carbon atoms.