Diazo Paper

Diazo Paper

 

paper covered on one or, less frequently, both sides with a thin layer of a photosensitive substance made from diazo compounds. The paper is used in photocopying in diazotype photocopiers.

The process of producing a visual image on diazo paper has two steps. In the first step—exposure—an unstable positive image is formed in the photosensitive layer; the image consists of sections of undecomposed diazo compounds remaining under opaque areas of the original document. In the second step—developing—the undecomposed diazo compounds are converted into light-stable azo dyes of black, brown, red, orange, blue, or violet color.

Diazo paper is classified according to the composition of the photosensitive layer as single-component, two-component, or hot-process. Single-component paper contains only a diazo compound, which is developed by the wet process in aqueous solutions of azo compounds. Two-component paper contains diazo and azo compounds and is developed by the dry process, usually in ammonia vapors. Hot-process paper contains, in addition to diazo and azo components, compounds that when heated release substances required for developing. Diazo paper is produced mainly in rolls 20 to 100 m long and 0.3 to 1.2 m wide. In addition to diazo paper, diazo tracing paper is produced on a translucent paper base for use in preparing duplicates and intermediate originals.

S. R. GAEVSKAIA

References in periodicals archive ?
Tenders are invited for Purchase of diazo paper (photosensitive)
The Ozalid copier used dyeline or diazo paper, known in German as Lichtpauspapier, which is "wet-strength paper with a light-sensitive layer to multiply text or drawings" (J.
Light penetration into crowns of individual trees was measured using diazo paper sensors (Friend 1961), that were calibrated with a quantum sensor (LI-COR, Lincoln, Nebraska, USA) under both sun and shade conditions.
The facility will occupy approximately 2 million square meters with its main products being corrugated paper, offset paper, writing paper and Diazo paper.
Tenders are invited for Ammonia Roll Paper Diazo Paper For Ammonia Vapour Development Width 1.
The method calibrated light-sensitive diazo paper against a standard light-measuring device.
a LI-COR Quantum or Line Sensor) are very expensive, and hence the diazo paper method became popular.
The objective of this study was to determine if the amount of accumulated photosynthetic photon flux density (PPFD) measured with a light meter is highly correlated with the number of exposed sheets of diazo paper under a variety of conditions.
Stacks of diazo paper (200SE Ozalid paper made by Film Paper Corporation Company of America) were constructed into booklets containing 20 sheets.
Tenders are invited for Amonia Roll Diazo Paper For Amonia Vapur Development Width 1.
serves a range of blueprinting and reprographic firms, producing diazo papers and films, xerographic papers, films and vellums and plotter papers, films and vellums.
Douglas' three aqueous coating lines, and sheeting and slitting converting equipment produce diazo papers and films, and xerographic papers, films and vellums.