Abstract:
A novel fluorinated aromatic acetal polymer comprises at least one unit of A and at least one unit of B or C, or at least one unit of each of A, B and C and optionally further comprises at least one unit of either D or E or at least one unit of each of D and E, wherein the units A and B and/or C, and optionally D and/or E are linked together by single covalent C-C bonds and have the formulae: 1 wherein RA is H or C1-C11 alkyl, or an aryl group that does not contain fluorine, and RB and RC are an aryl groups that contain fluorine. The polymer is prepared by reacting a hydrolyzed polyvinyl acetate polymer or copolymer with at least one non-fluorinated aldehyde component, and at least one fluorinated aromatic component. The polymer is useful is preparing a photosensitive composition which comprises at least one diazo resin and at least one such fluorinated aromatic acetal polymer. Such a photosensitive composition may be applied to a support to form an imageable member which may be imaged to form a lithographic printing plates.p
Abstract:
The present invention includes an imageable element, which can be: (a) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; a polyvinyl acetal binder; and a sheet substrate; or (b) an imageable element comprising an imaging layer which comprises: an aromatic diazonium salt containing compound having an alkoxy substituent and an aromatic diazonium salt containing compound free of an alkoxy substituent; and a sheet substrate. The imaging layer includes a total aromatic diazonium salt containing compound content of at least 10 weight percent. The molar ratio of the aromatic diazonium salt containing compound having an alkoxy substituent to the aromatic diazonium salt containing compound that is free of an alkoxy substituent is from about 1.0:1 to 70:1. Upon imagewise exposure and development, an imaged element is obtained, which is mounted on a dry printing press containing lithographic ink and used to produce printed stock.