| 摘要 |
1313143 Printing master MINNESOTA MINING & MFG CO 28 April 1970 [29 April 1969] 20434/70 Heading G2H [Also in Division H1] An electrographic recording member comprises a first layer adapted to provide an image pattern of conductive and non-conductive regions, a dielectric layer at least 6Á thick bonded to the first layer and a conductive layer bonded to the dielectric layer. The first layer is preferably photo-conductive and is exemplified by ZnO or TiO 2 dispersed in copoly styrene-butadiene and sensitized by Phosphine R, Setoflourine T and/or Rhodamine B, but other photo-conductors are specified. The dielectric layer may be polyethylene terephthalate, polypropylene, polyethylene, polystyrene, or polycarbonate but other materials are also exemplified. The conductive layer is preferably a vapour deposited layer of Al or Cu on the back of the dielectric layer or paper rendered conductive by a cationic resin, but other materials may be used. The conductive layer may be in the form of dots or lines or built up from a number of plys. Alternatively the first layer may be thermoconductive, for example hydrated Al 2 O 3 or SiO 2 in a binder. In an example a polyester film is coated with Cr and then an alcoholic aqueous dispersion of alumina. Materials that strongly supercool e.g. diphenylphathalate containing lithium salts or heat sensitive reactants that produce metallic species e.g. silver halides may also be used. Other materials specified for the first layer are semi-conductors or photo-insulators. The first layer may also be formed as a pattern of conductive materials corresponding to the pattern to be reproduced e.g. by painting or printing with a dispersion or graphite or silver. |
