Method of preparing lithographic printing plates

A method of lithographic printing comprising:

• A) imagewise exposing a negative-working lithographic printing plate precursor using infrared imaging radiation to provide both exposed and non-exposed regions in the imageable layer,
• said lithographic printing plate precursor comprising a substrate and having thereon an imageable layer comprising:
• a free-radically polymerizable component,
• an initiator composition that is capable of generating free radicals sufficient to initiate polymerization of said free-radically polymerizable component upon exposure to said imaging radiation in the presence of a radiation absorbing compound,
• a radiation absorbing compound having a λmax of from about 700 to about 1400 nm, and
• a primary polymeric binder that comprises recurring units derived from one or more N-alkoxymethyl(meth)acrylamides in an amount of from 20 to 75 weight %, based on the total dry primary polymeric binder weight, wherein said primary polymeric binder is present in an amount of from about 12 to about 70% based on total imageable layer dry weight,
• B) applying a single silicate-free and metasilicate-free processing solution off-press to said imaged precursor both (1) to remove predominantly only said non-exposed regions, and (2) to provide a protective coating over all of said exposed and non-exposed regions to provide a lithographic printing plate,
• said processing solution having a pH of from about 3 to about 11 and comprising at least 0.1 weight % of an anionic surfactant,
• C) removing excess processing solution from said lithographic printing plate without separate rinsing and gumming steps, and optionally drying said lithographic printing plate, and
• D) without removing said protective coating, using said lithographic printing plate for printing an image using a lithographic printing ink.

A method of making an image comprising:

• A) imagewise exposing a negative-working lithographic printing plate precursor using infrared imaging radiation to provide both exposed and non-exposed regions in the imageable layer,
• said lithographic printing plate precursor comprising a substrate and having thereon an imageable layer comprising:
• a free-radically polymerizable component,
• an initiator composition that is capable of generating free radicals sufficient to initiate polymerization of said free-radically polymerizable component upon exposure to said imaging radiation in the presence of a radiation absorbing compound,
• a radiation absorbing compound having a λmax of from about 700 to about 1400 nm, and
• a primary polymeric binder that comprises recurring units derived from one or more N-alkoxymethyl(meth)acrylamides in an amount of from 20 to 75 weight %, based on the total dry primary polymeric binder weight, wherein said primary polymeric binder is present in an amount of from about 12 to about 70% based on total imageable layer dry weight, and
• B) processing said imaged precursor on-press using a fountain solution, lithographic printing ink, or both, to remove predominantly only said non-exposed regions.

A negative-working lithographic printing plate precursor comprising a substrate and having thereon an imageable layer comprising:

• a free-radically polymerizable component,
• an initiator composition that is capable of generating free radicals sufficient to initiate polymerization of said free-radically polymerizable component upon exposure to imaging radiation in the presence of a radiation absorbing compound,
• a radiation absorbing compound having a λmax of from about 700 to about 1400 nm, and
• a primary polymeric binder that comprises recurring units derived from one or more N-alkoxymethyl(meth)acrylamides, provided that such recurring units are present in said primary polymeric binder in an amount of in an amount of from 20 to 75 weight % based on the total dry primary polymeric binder weight, wherein said primary polymeric binder is present in an amount of from about 12 to about 70% based on total imageable layer dry weight.