Isocyanate crosslinked imageable compositions

An imageable element comprising:

• a lithographic substrate having a hydrophilic surface;
• and
• a positive working imageable composition coated on the hydrophilic surface of said substrate, said composition comprising:
• a hydroxyfunctional resin comprising a covalently bound radiation sensitive group capable of increasing the solubility of said imageable composition in an alkaline developer upon exposure to radiation;
• an acid generator;
• a colorant;
• and
• an isocyanate crosslinking agent.

A method of producing an imaged element comprising the steps of:

• providing an imageable element comprising a lithographic substrate having a hydrophilic surface and a positive working imageable composition coated on the hydrophilic surface of said substrate, wherein said imageable composition comprises:
• a hydroxyfunctional resin comprising a covalently bound radiation sensitive group capable of increasing the solubility of said imageable composition in an alkaline developer upon exposure to radiation;
• an acid generator;
• a colorant;
• and
• an isocyanate crosslinking agent;
• heating said imageable element at a temperature and length of time sufficient to produce a crosslinked imageable element;
• imagewise exposing said crosslinked imageable element to radiation to produce an imagewise exposed element having exposed and unexposed regions;
• and
• removing the exposed regions of said imageable composition to produce said imaged element.