Process for making a cellulose triacetate photographic film base
AssigneeEastman Kodak Company
InventorEric Eugene Arrington
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Abstract
The invention provides a method of making a cellulose triacetate photographic film base which comprises providing a casting composition of cellulose triacetate, plasticizer, and solvent having a cellulose triacetate and plasticizer concentration of from 36% to 72% by weight, casting the coating composition at a temperature of from 40.degree. C. to 63.degree. C. unto a surface maintained at from -70.degree. C. to 21.degree. C. for a residence time from 3 to 8 seconds, in accordance with the equation Tr/Tg<1.9, where Tg and Tr are the glass transition temperature in degrees Kelvin and the temperature of the casting composition in degrees Kelvin at a point adjacent to the surface where the film base is separated from the surface.
Claims11
A method of making a cellulose triacetate photographic film base which comprises providing a casting composition of cellulose triacetate, plasticizer, and solvent having a cellulose triacetate and plasticizer concentration of from 36% to 72% by weight and a plasticizer to cellulose ratio of from 13 to 17 percent, casting the casting composition at a temperature of from 40.degree. C. to 63.degree. C. on to a surface maintained at from -70.degree. C. to 21.degree. C. for a residence time from 3 to 8 seconds, in accordance with the equation Tr/Tg<1.9, where Tg and Tr are the glass transition temperature in degrees Kelvin and the temperature of the casting composition in degrees Kelvin at a point wherein the film base is separated from the surface.
Dependencies are inferred from the claim text.