| 摘要 |
991,893. Photographic emulsions. HONEYWELL Inc. May 23, 1961 [May 25, 1960], No. 18604/61. Heading G2C. A light sensitive silver halide print-out emulsion is overcoated with a polymeric aqueous emulsion containing either cupric chloride or cupric bromide and a water-soluble formate. In the examples the polymeric aqueous emulsion is polyvinylacetate and the formate is sodium, potassium or ammonium formate. The cupric salt solution and the formate solution are mixed and added to the polymeric emulsion and this mixture applied to the silver halide emulsion by transfer, roller coating, dipcoating or spreading with a doctor knife. The silver halide emulsion may be prepared by precipitating silver bromo-iodide alone by adding hot ammoniacal s ilver nitrate to a hot solution of potassium bromide and potassium iodide dissolving this silver salt and cadmium iodide in water and dispersing this solution in hydroxyethyl starch and coating the emulsion on paper. Specification 924,658 is referred to. |
