| 摘要 |
A positive working thermal imaging medium, and a process of forming an image with it is disclosed. This thermal imaging medium comprises a transparant support and (1) a layer comprising a homopolymer or copolymer comprising at least 60 mole % of monomer units containing covalently bound chlorine, (2) a layer containing a homopolymer or copolymer comprising at least 50 mole % of a vinyl acetal monomer unit, (3) an image forming layer, (4) a release layer, and (5) a thermoadhesive layer. After or before exposure to a heat pattern generated directly by a thermal head or indirectly by information-wise exposure to laser radiation a cover sheet is laminated to layer (5). After delamination at least the layers (1), (2), and (3) adhere to said support in the information-wise non-exposed parts, and the layers (2), (3), (4) and (5) adhere to said cover sheet in the information-wise exposed parts thus forming a positive image on said support and a negative image on said cover sheet. |
