| 摘要 |
1,173,899. Photographic processes. KEUFFEL & ESSER CO. Dec.21, 1966 [Dec.28, 1965], No.57132/66. Heading G2C. A photographic process comprises imagewise exposing a support with a layer thereon containing a diazonium salt so that a latent image is produced and either the exposed or unexposed areas become capable of retaining a powder developer or do so on subsequent treatment and then developing the retentive areas by applying a powder developer. In the examples powdered diazonium salt is rubbed into a paper support and the material is imagewise exposed. The exposed areas are developed either with a coloured toner or a powdered coupler and the negative powdered image obtained is heated to fix it (when using a toner) or to develop a coloured image (when using a coupler). Alternatively, if powdered diphenylamine which may be admixed with carbon tetrabromide is used, a visible image is produced by exposure to ultraviolet radiation. If 2, 5-diethoxy 4-benzoylamido benzene diazonium chloride alone or 4-diethylamine-benzene diazonium borofloride or 2:5 diethoxy-4-morpholine benzene diazonium borofluoride admixed with trichloracetic acid is used, a positive coloured image is produced on development. Positive images are also produced by lengthening the exposure time or by dusting the exposed areas with polyethylene powder, heating and dusting the remaining areas with coloured toner. Printing plates are produced if a hydrophobic toner is used for development. Multi-colour line images are produced by imagewise exposure to a line negative and development with appropriate coloured toner and repeating the exposure and development. The preferred toner is a petroleum hydrocarbon resin and a dye. Reference has been directed by the Comptroller to Specification 1,105,112. |
