Silver-free positive or negative working registration materials - has ferroelectric or magnetic particles in a softenable binder, which become aligned under illumination in an applied field

摘要

Registration material comprises a support carrying a layer of radiation-sensitive material comprising (a) a solid ferroelectric or magnetic material (I) in particulate form having a dipole moment which changes leapwise under the influence of radiation at a temp. (T) which defines the registration temp. whilst in an externally applied force field, this causing a phase transition with a change in the electric or magnetic symmetry, or a photoelectret, and (b) a binder (II) with a softening pt. of less than (T). The particles of (I) are uniformly distributed in (II) to form a heterogenous mixt. and the (I) has a higher optical density than the (II). At temp. (T) and in the presence of the dipole, the particles of (I) have the facility for aligning into filaments perpendicular to the surface of the support. The material is provided with a protective layer (III) having an optical density lower than that of (I) or (II). The materials are silver-free prods. giving high contrast images directly upon exposure, without further processing. They are useful in document copying systems, print-outs for electronic calculators, photography, cinema and tlevision, and spectroscopy. . 3.