Degradation Test Materials

Two materials have been developed for testing of film transport mechanisms to detect malfunctions likely to damage photographic films. One material is intended for dry applications only, the other for applications where there is contact with aqueous solutions. The designations 'wet' and 'dry' degradation test material (DTM) have been applied to differentiate between the two. The dry DTM, a coating of solvent-filled microcapsules in a gelatin/polyvinyl alcohol matrix on a black base, produces a contrasing white mark at the site of a scratch or abrasion. The wet DTM, a coating of empty microcapsules in a similar matrix, has a white surface covering the black base. Damage to this DTM causes localized removal of the white coating to reveal the black background. Versions of both DTMs have been produced on a flashbed, processed Estar-based film substrate. The major part of the program described in this report was an attempt to provide a wet DTM on a dyed black polyester substrate. Satisfactory results were not obtained because coatings either lost much of their contrast after contacting aqueous solutions or had poor wet rub resistance. Formulations having good wet rub resistance showed excessive contrast loss while formulations retaining their contrast had poor wet rub resistance. (Author)