Photographic compositions and processes

• Main Authors: LAND EDWIN H, WOODWARD ROBERT B, GREEN MILTON, TRACY HELEN J, BLOUT ELKAN R, COHEN SAUL G
• Format: Patent
• Language: English
• Published: 21.10.1958
• Subjects: AUXILIARY PROCESSES IN PHOTOGRAPHY; CINEMATOGRAPHY; ELECTROGRAPHY; HOLOGRAPHY; PHOTOGRAPHIC PROCESSES, e.g. CINE, X-RAY, COLOUR,STEREO-PHOTOGRAPHIC PROCESSES; PHOTOGRAPHY; PHOTOSENSITIVE MATERIALS FOR PHOTOGRAPHIC PURPOSES; PHYSICS

751,304. Photographic composition and process. INTERNATIONAL POLAROID CORPORATION. July 7, 1954 [Sept. 4, 1953], No. 19882/54. Class 98 (2). For forming water-soluble complex salts with silver halide and therefore useful as fixer, but more particularly useful, when containing a developer, in forming a transfer image in a receptive element in contact with an exposed silver halide layer, the composition comprises a specified cyclic diketo imide together with a nitrogenous base in aqueous alkaline solution. Sulpho residues from the use of hypo in the image-transfer process are thus avoided. Diketo triazines, barbiturates, uracils, urazoles, hydantoins, glutarimides, glutaconimides, succinimides and maleimides of which 24 are specified are preferred as imides, and ammonia, amines, hydroxylamines and hydrazines are included in 35 specified nitrogenous bases. High alkalinity, provided as by caustic soda or potash, or by certain of the nitrogenous bases such as diethylamine or allylamine alone, is preferred. P-amino-phenol may function as both nitrogenous base and developer for the composition, and other developers are listed. Preferably the compositions are viscous, and they may include thickening agents for this purpose. They may be confined in rupturable containers whereby a thin layer of composition may be provided between the exposed layer and the receptive element with the aid of pressure rollers, for quick production of the finished prints in the manner described in Specification 684,592. In Example 1 the composition comprises specified proportions of water, sodium carboxymethyl cellulose, sodium hydroxide, sodium sulphite, barbituric acid, hydroquinone, metol and aminoethyl ethanol amine. Thirty further examples are directed to replacements for the barbituric acid and the amine of Example 1. Specification 703,231 also is referred to.