Eastman-Kodak Company

Daniel G Ocorr

Wilbur S Gaugh

Eugene H Barbee

Christopher J Klasner

Kathleen A Bonsignore

Avonelle L Leonard

Photographic materials, such as films and papers, include a support and coatings on the support. The coatings often contain hardeners which cause gelation cross links in the binder in the coating. The extent to which the cross-links have formed at the time of processing of the film or paper affects the appearance of the image produced by processing. Conventionally the cross-links have been allowed to form with time in normal atmospheric conditions. According to the invention, the formation of the cross links is accelerated to substantial completion by a process including incubating the material at a temperature above the glass transition temperature of the coating and below the melting point of the coating in an atmosphere having a relative humidity which causes a moisture content of the coating of 0.1 to 0.25 for a period of time sufficient to substantially complete the hardening, that is, the formation of the cross-links. Such period of time is less than ten minutes and can, with some materials and conditions, be as short as a minute or less. After the incubation step, the temperature of the coating is reduced below its glass transition temperature, the moisture content is reduced and the coating is then cooled prior to windup of the support with the coating thereon. The incubation and related steps of the invention may be performed after the coating and drying of the material and prior to windup into a roll or they may be performed in a rewind situation. A rewind situation is one in which a support has been coated and the coated support has been dried, cooled and wound up into a roll. The roll is subsequently unwound, operated upon in accordance with the invention and then rewound into a roll. After treatment in accordance with the invention, the roll of photographic material may immediately be tested and certified and passed to further operations in which it is cut into sizes usable by the consumer. Apparatus for performing the invention is also disclosed.

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Rochester, NY, United States of America

Daniel G Ocorr