| 摘要 |
<p>The invention provides new compositions which change colour on exposure to actinic radiation and contain a photosensitive onium, e.g. iodonium or sulphonium, salt and a dyestuff which changes colour when protonated. The compositions may also include a resin, especially a resin curable by the onium salt when the latter is exposed, and preferably an epoxy resin. The compositions are useful especially as coatings, e.g. for making screen stencils or for producing lithographic printing plates.</p> |
