Dimensionally stabilized imaging element and method

Claim 1

In a method of making an imaging element comprising, on a polymeric film support, at least one layer comprising an amine-generating composition that includes a reducible cobalt(III) complex containing releasable amine ligands, and an amine-responsive dye precursor; the method comprising the steps of (a) coating said composition and said precursor onto a support having dimensional changes that are no greater than ±0.1% in width and length when heated in an uncoated state for about 5 seconds at a temperature of about 125° C., to form at least one layer and; (b) drying said layer to form the element; the improvement wherein said method further includes, prior to exposure of the element to activating radiation, the additional steps of (c) dimensionally stabilizing said dried element by heating said dried element to a temperature of between about 100° C. and about 140° C. for a length of time sufficient to form in said element an overall thermal-reaction hysteresis that produces dimensional changes of no greater than ±0.03% in width or length when said element is processed by heating for about 5 seconds at a temperature of about 125° C.

Claim 6

A method of dimensionally stabilizing a dried imaging element comprising, on a polymeric film support, at least one layer comprising an amine-generating composition that includes a reducible cobalt(III) complex containing releasable amine ligands, and an amine-responsive dye precursor; said support having dimensional changes that are no greater than ±0.1% in width and length when heated in an uncoated state for about 5 seconds at a temperature of about 125° C.; the method comprising prior to exposure of the element to activating radiation, the step of dimensionally stabilizing said element by heating said element to a temperature of between about 100° C. and about 140° C. for a time of between about 2 and about 20 seconds, whereby the overall thermal-reaction hysteresis of the element provides a dimensional change of no greater than ±0.3% in width or length when processed under the heating conditions of step (a) by heating for about 5 seconds at a temperature of about 125° C.

Claim 7

A method of dimensionally stabilizing a dried imaging element comprising, on a polymeric film support, at least one layer comprising an amine-generating composition that includes a reducible cobalt(III) complex containing releasable amine ligands, and an amine-responsive dye precursor; said support having dimensional changes that are no greater than ±0.1% in width and length when heated in an uncoated state for about 5 seconds at a temperature of about 125° C.; the method comprising prior to exposure of the element to activating radiation, the step of dimensionally stabilizing said element by heating said element to a temperature of between about 100° C. and about 140° C. for a time of between about 2 and about 20 seconds, whereby the overall thermal-reaction hysteresis of the element provides a dimensional change of no greater than ±0.3% in width or length when processed under the heating conditions of step (a) by heating for about 5 seconds at a temperature of about 125° C.