Abstract: A lithographic printing plate precursor has an infrared radiation-sensitive image-recording layer containing an IR absorber, and an ozone-blocking material of 1500 or less molecular weight and has structure (I), (II), or (III): wherein R is a hydrocarbon having 14-30 carbon atoms; m is 1 or 2; n is 1-6; the sum of m and n is >2 and <8; and A is a multivalent organic moiety free of R and OH groups and has a valence m+n; wherein R1 and R2 are alkyl groups of 14-22 carbon atoms, and o is 1-3; R3C(?O)NR4R5?? (III) wherein R3 is an alkenyl with a C?C bond within a carbon-carbon chain of 16-30 carbons, and R4 and R5 are hydrogen or unsubstituted alkyls of 1-4 carbon atoms. Such ozone-blocking materials can be used to protect infrared radiation-sensitive dyes that may be degraded by ozone and thus improve imaging sensitivity.

Abstract: A lithographic printing plate precursor has an infrared radiation-sensitive image-recording layer containing an IR absorber, and an ozone-blocking material of 1500 or less molecular weight and has structure (I), (II), or (III): wherein R is a hydrocarbon having 14-30 carbon atoms; m is 1 or 2; n is 1-6; the sum of m and n is >2 and <8; and A is a multivalent organic moiety free of R and OH groups and has a valence m+n; wherein R1 and R2 are alkyl groups of 14-22 carbon atoms, and o is 1-3; R3C(?O)NR4R5?? (III) wherein R3 is an alkenyl with a C?C bond within a carbon-carbon chain of 16-30 carbons, and R4 and R5 are hydrogen or unsubstituted alkyls of 1-4 carbon atoms. Such ozone-blocking materials can be used to protect infrared radiation-sensitive dyes that may be degraded by ozone and thus improve imaging sensitivity.