| abstract |
FIELD: chemistry. n SUBSTANCE: the invention relates to polymer colouring agents used in coating compositions to protect the image forming layer of the offset plates. Described are a new water-soluble polymer colouring agent with the absorption band ranging from about 300 nm to about 600 nm, and a coating composition for a thermographic offset plate which comprises: (a) the said polymer colouring agent with the absorption band ranging from about 300 nm to about 600 nm, and (b) organic microparticles which contain cross-linked copolymers of acrylate ot methylacrylate and styrole, 2-hydroxymethylacrylate, methacrylate, poly(oxyethylene)methacrylate or a linear or branched alkylmethacrylate; or inorganic nanoparticles containing silicone oxide or aluminium oxide. Described is the thermographic offset plate for reverse printing, containing (a) water receptive plate, (b) a layer positioned on the plate which forms the image in the near-infrared region, and (c) the coating layer which is positioned on the image-forming layer and contains the said coating composition. n EFFECT: reduction or elimination of background filling of the offset plates in the conditions of white light, elimination of the need to use separating paper when packaging offset plates. n 7 cl, 10 dwg, 13 ex |