Abstract: A method and apparatus for drying a coated web is taught that reduces dryer induced mottle. The apparatus comprises a plurality of ducts positioned in series within an enclosure, the coated web travelling through the enclosure in a direction of travel, each duct including an arcuate portion terminating in a discharge nozzle, each discharge nozzle directed such that air exiting therefrom is flowing generally parallel to the coated web and in the direction of travel of the web; and at least one of the plurality of ducts having a baffle plate extending back therefrom toward another one of the plurality of ducts upstream thereof, the baffle plate being generally parallel to the coated web. Each duct preferably also includes a plate extension projecting from a bottom portion of the discharge nozzle in the direction of travel of the web, the plate extension being substantially parallel to the coated web.

Abstract: A method and apparatus for drying a coated web is taught that reduces dryer induced mottle. The apparatus comprises a plurality of ducts positioned in series within an enclosure, the coated web travelling through the enclosure in a direction of travel, each duct including an arcuate portion terminating in a discharge nozzle, each discharge nozzle directed such that air exiting therefrom is flowing generally parallel to the coated web and in the direction of travel of the web; and at least one of the plurality of ducts having a baffle plate extending back therefrom toward another one of the plurality of ducts upstream thereof, the baffle plate being generally parallel to the coated web. Each duct preferably also includes a plate extension projecting from a bottom portion of the discharge nozzle in the direction of travel of the web, the plate extension being substantially parallel to the coated web.

Abstract: An apparatus and method for evaporating a coating solvent from a coating on a substrate and for minimizing the formation of mottle. The coating is heated with a first drying gas at no higher than a first heat transfer rate. The first heat transfer rate is created by a first heat transfer coefficient and a first temperature difference between the first coating temperature and the first drying gas temperature. The first heat transfer rate causes maximum evaporation of the coating solvent yet insignificant formation of mottle when the coating is at the first coating thickness and the first coating viscosity.

Abstract: An apparatus and method for evaporating a coating solvent from a coating on a first substrate surface of a substrate and for minimizing the formation of mottle as the coating solvent is evaporating. A drying oven includes an enclosure having an inlet and an outlet and defining a first drying zone. A plurality of drying subzones are within the first drying zone. At least two of the plurality of drying subzones employ different and controllable drying conditions. Physical barriers are not required to create the plurality of drying subzones.

Abstract: An apparatus and method for evaporating a coating solvent from a coating on a first substrate and for minimizing the formation of mottle. A drying oven includes a plurality of air foils positioned adjacent to the second substrate surface. Each of the plurality of air foils have a foil slot through which a stream of drying gas is supplied to the drying oven. The foil slot length is adjusted to not be significantly greater than the first substrate width to minimize air flow over the first and second coating edges which minimizes the creation of mottle.

Abstract: Reduction of mottle and other surface anomalies in photothermographic and thermographic elements is reduced by the incorporation of a fluorinated polymer containing at least two different groups within the polymer chain derived from reactive monomers, the groups being: a fluorinated, ethylenically unsaturated monomer; and a polar, ethylenically unsaturated monomer.

Abstract: A fluorinated polymer comprising at least three different groups within the polymer chain derived from reactive monomers, the monomers comprising:(a) a fluorinated, ethylenically unsaturated monomer;(b) a hydroxyl-containing, ethylenically unsaturated monomer; and(c) a polar, ethylenically unsaturated monomer.The fluorinated polymers provide a surfactant that is particularly useful in the coating of polymeric layers. The surfactants can reduce surface anomalies, such as mottle when used to coat photothermographic and thermographic elements from certain solvent systems. The present invention also provides photothermographic and thermographic elements comprising the foregoing fluorinated polymers.