| 摘要 |
1275616 Photographic silver halide dye diffusion transfer material POLAROID CORP 22 July 1969 [22 July 1968] 36873/69 Heading G2C A process of forming a composite print comprising a positive image that is over a negative image and that is viewable without separation of the two images as a positive reflection print, comprises exposing a silver halide emulsion layer having associated therewith a compound providing as a function of exposure an imagewise distribution of dye image-forming material, applying alkaline processing composition and thereby developing the silver halide emulsion and forming an imagewise distribution of mobile dye image-forming material as a function of point-to-point degree of exposure, at least a portion of the mobile dye image-forming material being transferred by diffusion to a superposed image-receiving layer and thereby forming a positive dye image therein, in which process an opaque layer is between the silver halide layer and the image-receiving layer or is formed between these layers in the process, the silver halide layer and the image-receiving layer are present as a laminate all the layers of which are permeable to the alkaline processing composition, and the laminate is sandwiched between two support layers that are less permeable than the layers of the laminate, are flexible and react to the presence of moisture in the laminate in a manner which is symmetrical with respect to the laminate, at least the support layer adjacent the image-receiving layer being transparent. The processing composition may be contained in a rupturable container attached to the laminate. Discharge of the contents of the rupturable container is preferably effected between the image-receiving and silver halide layers. The processing composition may contain an opacifying agent. The support layers may be of the same or different material, as long as their reaction to moisture is symmetrical with respect to the laminate. The support layers are preferably formed of a polyester derived from ethylene glycol and terephthalic acid, but may be formed from paper, vinyl chloride polymers, polycarbonates, phenylene oxide polymers, acrylic polymers, polyethylene or polypropylene. |
