Abstract: A method for measuring the dynamic surface tension (DST) of a proposed outer layer of a liquid composition, to be curtain or slide hopper coated, over a range of surfactant levels to determine the surfactant concentration which produces the maximum resistance to air currents. Measurements are made by the Wilhelmy Blade Method, in which a surface of a pool of composition to be measured is placed in contact with the lower edge of a suspended blade. The static method is modified such that the surface of the composition touching the blade is continually refreshed to simulate the formation of fresh curtain surface by pumping the composition upwards through an open cylinder and allowing the composition to spill over the edges (“overflowing weir”). The bulk surfactant concentration providing maximum resistance to coated streakiness or mottle is highly correlated with the concentration providing maximum surface tension gradients in the overflowing weir apparatus.

Abstract: An imaging support element comprising a polymeric film support and a thermally stable single subbing layer is made by forming a coating over the polymeric film support, the coating having a surface including amine reactive groups in a density of at least 1010 per cm2 and then heat treating the polymeric film support with the coating thereon at a temperature in the range of from about 50° C. below the glass transition temperature (Tg) of the polymeric support up to the glass transition temperature (Tg) of the polymeric support. The polymeric film support is nitrogen plasma treated. The layer is preferably formed by coating a monomer solution on the nitrogen plasma treated polymer support wherein the coated monomer has at least two vinyl sulfone groups which provide the amine reactive groups. Alternatively, the layer may be formed by applying to the polymeric support web a coating including at least one non-amine reactive comonomer and at least one comonomer having amine reactive side groups.