| 摘要 |
A processless lithographic printing precursor comprising a substrate, a layer of imaginable element on the substrate. The imaginable element comprising: (1) a substance capable of converting radiation into heat; (2) anionic polymer particles and (3) cationic polymer particles. The imaginable element can not be removed by water or fountain used for press when coated and dried, and becomes hydrophobic under the action of heat. The converter substance may be selected to have an absorption spectrum that is optimized to absorb at the wavelength of imaging radiation. The anionic polymer particles have an anionic surface and cationic polymer particles have a cationic surface. The processless lithographic printing precursor so created may be imaged using absorbed radiation that is imagewise converted to heat, resulting in areas of hydrophobic property, while unimaged areas retain their hydrophilic property. This allows the latent image so formed to be employed in creating a negative-working lithographic printing master. The negative-working lithographic printing master so created is irreversible, does not require a substrate of controlled hydrophilicity and provides great toughness in the exposed areas.
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