When color photographic materials are stored as records semipermanently, the extent of light-fading and dark-fading should be suppressed as much as possible and the color balance of three-color-fading among the yellow, magenta, and cyan dye images should be retained as in the initial state. However, the extent of light-fading and dark-fading of the yellow, magenta, and cyan dye images differs from dye image to dye image, and after long-term storage, the color balance of three-color-fading is lost and the image quality of the dye images deteriorates.
Dark-fading of the yellow dye image and the cyan dye image in an environment high in humidity is greater than that of the magenta dye image, and the color balance is lost considerably in some cases. Further, when the photographic material is stored under such conditions, mold occurs on the photographic material surface and the cyan dye image and the yellow dye image are faded extremely by organic acids (e.g., acetic acid, citric acid, tartaric acid, and gluconic acid) secreted from the fungi, thereby leaving red spots in the image, for example, of a color print. Such a defect is often found in areas high in both temperature and humidity, for example, in the southern district of Japan (e.g., Okinawa and Shikoku), and in the case of important photographs which are desired to be preserved as records, such as wedding photographs, although a measure of laminating the photographs is taken, not only is the operation complicated and laborious, but deterioration of the image quality cannot be obviated anyway. Even if mold does not occur, when the pH of the surface of the produced photographic image is low due to the type or scatter of conditions of the development processing, bleach-fix processing, or stabilization processing, fading of the cyan dye image and the yellow dye image is also promoted.
To solve such problems, with respect to cyan dye images, for example, JP-B ("JP-B" means examined Japanese patent publication) No. 45017/1983 and JP-A ("JP-A" means unexamined published Japanese patent application) Nos. 75447/1987, 129853/1987, 172353/1987, 196657/1987, and 21447/1989, and with respect to yellow dye images, for example, JP-A Nos. 50048/1989, 50049/1989, and 4041/1986, disclose the use of cyclic ether compounds or epoxy-group-containing compounds, and although it is recognized that these compounds have an effect to a certain extent on the improvement of fastness to dark-fading and acid-fading, the improvement is still unsatisfactory, and in some cases there are injurious effects that fading or insufficient color restoration occurs due to the leuco dye formation of a cyan dye formed when the photographic material is processed in a bleach-fix bath containing an exhausted solution.
The cyan dye image obtained from phenol couplers having as a ballasting group a straight-chain or branched alkyl group, described in JP-A No. 39045/1986, is excellent in fastness to light and heat, but it has defects that it is poor in fastness to the above-mentioned acids and the unexposed part (white background) is colored cyan with long-term storage. A method for solving the latter problem by additionally using a certain epoxy compound is described in JP-A No. 21447/1989, but the method is insufficient for improvement in the former problem: acid-fading.
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USPTO Backgrounds