Trans World Technology Laboratories, Inc.

Trans World Technology Laboratories, Inc. (twt Labs Inc.)

Gilbert Zweig

David P Habib

A diazotype material useful for making duplicates of continuous tone originals, such as X-ray films, comprising a transparent film support having a coating of a layer thereon consisting essentially of at least two light-sensitive diazo compounds having different photolysis rates, couplers for the diazo compounds, an ultraviolet radiation absorbing material and homogeneously distributed in the layer at least about 7% by weight, based on the weight of lacquer, of an inert particulate material such as silica. The use of this material makes it possible to approximate a logarithmic photolysis, thereby providing sufficient linearity in the corresponding characteristic curve to achieve the desired duplicating results.

Continuous tone diazo material

Continuous tone diazotype process

A method for the amplification or intensification of dye images formed in a negative-working diazo system which comprises the steps of: (1) initially image-wise exposing a negative-working diazo layer to actinic radiation sufficient to convert a portion of the diazo compound contained therein to an active coupling constituent in the light-struck areas to form a first latent image, (2) developing the exposed diazo layer to effect coupling so as to form colored incipient images in the light-struck areas, (3) exposing the entire diazo layer from the same side as the initial image-wise exposure to actinic radiation of a greater amount than that used in the initial exposure, said amount of actinic radiation being sufficient to substantially photolyze the non-image areas while simultaneously creating second latent images beneath the already-developed areas, and (4) developing the exposed diazo layer again to effect coupling in said second latent image areas to form color therein and to amplify the initial colored incipient images. Further amplification may be obtained by exposing the diazo layer from the side opposite that of the initial exposure and again developing to effect coupling of any remaining diazo under the original dye image areas.

Growing community of inventors

Barrington, RI, United States of America

Gilbert Zweig