| 摘要 |
1298224 Printing plates by laser treatment of polyacetals E I DU PONT DE NEMOURS & CO 1 Dec 1969 [4 Dec 1968] 58497/69 Heading C3P [Also in Division H1] A polymeric printing plate is obtained by subjecting the surface of the plate to a focused laser beam of sufficient intensity to decompose and form depressions in the surface and controlling the position and intensity of the beam to form a pattern of predetermined shape and depth. The plate is composed of polymers containing certain structural units. They are typically polychloral, formaldehyde or ethylene oxide/hexafluoroacetone copolymers, end-capped polyoxymethylene, polythiocarbonyl fluoride, or chloral/pchlorophenylisocyanate copolymer. |
