| 摘要 |
An infrared sensitive, positive-working, image forming composition and element are disclosed. The image forming composition comprises a 1,1-di[(alkylphenoxy)ethoxy]cyclohexane, an infrared absorbing dye having a maximum absorption peak in the range of from about 700 nm to about 1100 nm, and a novolac polymer. The composition is applied and dried on a planar, hydrophilic substrate to form an image forming element, in particular, a planographic printing plate. Upon imagewise exposure to a near-infrared radiation source, the infrared dye absorbs light in the exposed areas and converts it to heat, which causes a disruption in the matrix of the image forming composition. Upon development with an aqueous alkaline developer, the exposed areas are removed while the nonexposed areas remain, thus forming a positive image. |
