Irradiation of polyacrylate films in air

Claim 1

The process of curing a composition to a non-tacky state said composition comprising at least 15% by weight of radiation polymerizable components having the formula A.sup.1 --Z--A.sup.2 ( 1) wherein A 1 and A 2 independently are ethylenically unsaturated terminal groups having terminal ethylenic unsaturation and having the formula ##STR22## wherein R--O-- is a monovalent residue of an aliphatic terminally unsaturated primary alcohol, ROH, formed by the removal of the active hydrogen from the primary --OH group, R having the formula: [E--CH.sub.2).sub.b ].sub.m R.sup.5 --CH.sub.2).sub.c wherein E is ##STR23## c is an integer of from 1 to 6, b is zero or an integer of from 1 to 6, R 1 and R 4 independently represent hydrogen or methyl, R 5 is an aliphatic group having from 1 to 15 carbon atoms, and no more than two catenary oxygen or carboxy groups, a valence of m+1, m is an integer of from 1 to 5, R 2 represents hydrogen or groups of the formula or ##STR24## wherein R 6 represents alkyl or alkenyl groups, R 7 is an aliphatic or aromatic group of up to eight carbon atoms, R 3 is an alkylene group of from 1 to 6 carbon atoms with up to one catenary oxygen atom, and Z is a heterocyclic group of the formula ##STR25## wherein X is a divalent group which is required to complete a 5- or 6-membered heterocyclic ring, or ##STR26## wherein R 12 and R 13 independently represent hydrogen or methyl, R 14 represents hydrogen, an alkyl group, or a phenyl group, R 13 and R 14 together may represent a trimethylene or tetramethylene group, m represents a number of from 1 to 30, n is 2 or 3, and a represents a group of the formula ##STR27## wherein X 1 represents the divalent radical necessary to complete a 5- or 6-membered heterocyclic ring group, said process comprising exposing said composition to radiation within the ultraviolet and visible spectral region while the composition is in the presence of an atmosphere of at least 2% by volume of oxygen to polymerize said components having formula (1) or (2) wherein said composition is in the form of a film on a substrate.