LOW-VOLATILITY, SUBSTITUTED 2-PHENYL-4,6-BIS (HALOMETHYL)-1,3,5-TRIAZINE FOR LITHOGRAPHIC PRINTING PLATES

The present invention sets forth the incorporation of a substituted 2-phenyl-4,6-bis (trichloromethyl)-1,3,5-triazine in photoresists of lithographic printing plates for the purpose of promoting their shelf-life, room light stability, and developability. The present invention provides a photocurable composition comprising at least a photopolymerizable ethylenically unsaturated monomer having at least one terminal ethylenic group and capable of forming a polymer upon exposure to actinic radiation; and an s-triazine capable of initiating free radical polymerization of the photopolymerizable ethylenically unsaturated monomer and being represented by general formula (I), wherein R1 is either OR4 or NR5R6, wherein R5 and R6 may or may not be identical with each other, either R5 or R6 may represent hydrogen, and wherein R4 and at least one of R5 and R6 represent a ballast group capable of preventing the substantial volatilization of the s-triazine from the photoresist composition, the ballast group being a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group, the substituted or unsubstituted alkyl group having at least 4 carbon atoms, the substituted or unsubstituted aryl group having at least 6 carbon atoms; R2 and R3 may or may not be identical with each other and each represents hydrogen, halogen, phenyl, a substituted or unsubstituted alkyl group, or an alkoxyl group; X and Y may or may not be identical with each other and each represent chlorine or bromine; and m and n may or may not be identical with each other and are each an integer of 0, 1, or 2. Desirable compositions will further comprise at least one photooxidizable leuco triarylmethane dye.