Radiation imagery chemistry: process – composition – or product th – Color imaging process – Using identified radiation sensitive composition in the...
Patent
1994-08-31
1996-08-27
Le, Hoa Van
Radiation imagery chemistry: process, composition, or product th
Color imaging process
Using identified radiation sensitive composition in the...
430379, 430407, 430430, 430460, 430461, G03C 742
Patent
active
055500102
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a color photographic processing method, and a product for color photography comprising, in addition to the conventional light-sensitive silver halide layers, a top layer which is insensitive to light.
U.S. Pat. No. 4,596,764 describes a photographic processing method which consists of bringing into contact, during the photographic processing, a product comprising light-sensitive silver halide emulsion layers with a high iodide content and an emulsion layer which is not sensitive to light with an amino compound (I) of the formula: ##STR1## wherein M represents a hydrogen atom, an alkali metal, an alkaline earth metal, a quaternary ammonium group, a quaternary phosphonium group, an amidino group or a group of the formula ##STR2## wherein R.sup.1 and R.sup.2 each represent separately a hydrogen atom or an aliphatic group, and m represents an integer between 2 and 4; or with a strong acid salt.
The protective layer described in this patent comprises a fine-grain emulsion with an iodide content of less than 3% molar, the quantity laid down to form this top layer being between 50 and 140% molar of the total quantity of silver iodide in the light-sensitive layers. It is clear in the art that when a photographic product contains a large quantity of silver iodide, the fixing has a reduced efficiency related to the low solubility of the silver iodide. The method described in the patent cited above proposes to avoid the problem encountered during the fixing stage by processing the color photographic product described above in the presence of a compound (I).
The examples in U.S. Pat. No. 4,596,764 show that, in the presence of a compound (I), the best sensitometric results are obtained when the protective layer consists of a pure bromide emulsion or a pure chloride emulsion with very fine halide grains, of the order of 0.07 .mu.m, with however a slight increase in fogging. In all the examples, the photographic products contain at least 5% molar of silver iodide in each light-sensitive layer. After exposure, these products are brought into contact with a compound of formula (I) by means of a separate bath used before the bleaching and fixing baths.
U.S. Pat. No. 4,640,890 describes a color photographic product comprising a base, at least one red-sensitive layer, one green-sensitive layer and one blue-sensitive layer, with, in at least one of these sensitive layers, a monodisperse emulsion. The photographic product comprises moreover an additional layer consisting of a non light-sensitive silver halide emulsion with a chloride content greater than 75% molar. This additional layer makes it possible to decrease the variations in the sensitometric characteristics during the processing. In fact, it has been found that the sensitometric characteristics vary greatly according to the agitation of the developer.
The examples in U.S. Pat. No. 4,640,890 show the differences in sensitivity and contrast of the product of the invention processed in an agitated developer and in a non-agitated developer. It can be noted that the higher the chloride content, the smaller are the variations in the sensitometric characteristics. These results are even more improved when the additional layer contains a rhodium salt.
The present invention makes it possible to remedy the problem of variations in sensitivity due to contamination of the baths during automatic processing of the photographic products. In fact, in some automatic processing machines, the photographic products pass from one bath to another by means of a conveyor belt made from plastic material such as polypropylene or nylon. These plastic materials at the same time convey small quantities of chemical compounds contained in the photographic baths. These compounds conveyed on the belt contaminate the different photographic baths during the remainder of the processing. For example, it has been observed that certain bleaching accelerator compounds, initially present in the bleaching or bleach-fixing baths, are partly conveyed on the conveyor belt and ar
REFERENCES:
patent: 1905188 (1933-04-01), Sease
patent: 3728121 (1970-08-01), Zorn et al.
patent: 3790384 (1974-02-01), Oishi et al.
patent: 4229525 (1980-10-01), Ueda
patent: 4369248 (1983-01-01), Ranz et al.
patent: 4456681 (1984-06-01), Kadowaki et al.
patent: 4542091 (1985-09-01), Sasaki et al.
patent: 4596764 (1986-06-01), Ishimaru
patent: 4614707 (1986-09-01), Fujita et al.
patent: 4640890 (1987-02-01), Fujita et al.
patent: 4812390 (1989-03-01), Giannesi
patent: 4873181 (1989-10-01), Miyasaka et al.
patent: 5009988 (1991-04-01), Yagi et al.
patent: 5360709 (1994-11-01), Ohkawa et al.
Begel Yannick
Bredoux Fran.cedilla.ois J.
Freisz Henri
Eastman Kodak Company
Le Hoa Van
Tucker J. Lanny
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