摘要:
Negative-working lithographic printing plate precursors have improved bakeability and good shelf life and can be imaged using either UV or infrared radiation. These precursors have a negative-working imageable layer that has a unique polymeric binder comprising a polymeric backbone and further comprising at least (a) and (b) pendant groups distributed in random order along the polymeric backbone. The (a) pendant groups are ethylenically unsaturated polymerizable groups, and the (b) pendant groups are defined by Structures (I), (II), and (III) described in the disclosure.
摘要:
A lithographic printing plate precursor comprises an imageable layer comprising a free radically polymerizable component, an initiator composition capable of generating free radicals upon exposure to imaging infrared radiation, an infrared radiation absorbing dye comprising an infrared radiation absorbing cation and a counter anion, and a polymeric binder. The salt formed between the infrared radiation absorbing cation and a tetraphenyl borate has solubility in 2-methoxy propanol at 20° C. that is greater than or equal to 3.5 g/l. The use of these infrared radiation absorbing dyes in the imageable layers provides a reduced tendency of these dyes to crystallize in the presence of tetraaryl borate counter anions.
摘要:
A lithographic printing plate precursor comprises an imageable layer comprising a free radically polymerizable component, an initiator composition capable of generating free radicals upon exposure to imaging infrared radiation, an infrared radiation absorbing dye that is defined by Structure (I) shown in the disclosure, which dyes comprise one or more ethylenically unsaturated polymerizable groups in an organic group that is attached to the methine chain. These infrared radiation absorbing dyes exhibit a reduced tendency to crystallize in the imageable layers in the presence of tetraaryl borate counter anions and therefore provide improved shelf life.
摘要:
Negative-working imageable elements such as lithographic printing plate precursors, include a free-radically polymerizable component, an initiator composition that is capable of generating free radicals sufficient to initiate polymerization of the free-radically polymerizable component upon exposure to imaging radiation in the presence of a radiation absorbing compound, a radiation absorbing compound, an aerobic free radical inhibitor, optionally a polymeric binder that is not a free radically polymerizable component, and an anaerobic free radical inhibitor. The molar ratio of the anaerobic free radical inhibitor to the aerobic free radical inhibitor is at least 1:1. This combination of inhibitors provides increased shelf life and good latent image stability particularly when the element includes a polymeric topcoat layer that functions as an oxygen barrier.
摘要:
Negative-working imageable element can be used to prepared lithographic printing plates. These elements include a water-soluble contrast dye having a λmax in the range of from about 450 to about 750 nm and having an absorption that is lower than 10% with respect to the absorption of the radiation absorbing compound in the element at the wavelength used for exposure. The contrast dye is present in sufficient H-aggregation such that less than 40% of the entire absorption spectrum from the contrast dye is contributed by it in non-H-aggregated form.
摘要:
Negative-working imageable elements can be imaged and processed to provide lithographic printing plates. These imageable elements are sensitive to infrared radiation but are insensitive to “white” light and thus can be more easily handled under white light conditions. These properties are possible by incorporating a filter dye having a λmax of from about 300 to about 500 nm into the imageable layer of the imageable elements.
摘要:
The radiation-sensitive composition and the negative working imageable element include a cationic IR absorber with tetraarylborate counteranion and an onium initiator with tetraarylborate counteranion. The use of these components provides high imaging sensitivity, good shelflife and high print run length.
摘要:
Lithographic printing plate precursor comprising (a) a lithographic substrate with a hydrophilic surface and (b) a radiation-sensitive coating on the hydrophilic surface comprising (i) one or more types of monomers and/or oligomers and/or polymers, each comprising at least one ethylenically unsaturated group accessible to a free-radical polymerization, (ii) at least one sensitizer, and (iii) at least one coinitiator capable of forming free radicals together with the sensitizer, said coinitiator being other than metallocenes, characterized in that the at least one sensitizer comprises a compound of formula (I) wherein at least one of the groups R9 to R12 is a bulky group which has a van der Waals volume of at least 55 Å3.
摘要:
Negative-working imageable element can be used to provide lithographic printing plates. The imageable element has a suitable radiation-sensitive imageable layer and a water-soluble overcoat disposed on the imageable layer. This overcoat comprises at least one poly(vinyl alcohol) having a saponification degree of at least 90%, an alkoxylation product of an alkanol, and either a 2-sulfonato succinic acid dialkylester or an alkoxylation product of a 1,4-butanediol.
摘要:
Lithographic substrate comprising (a) a dimensionally stable plate- or foil-shaped support, (b) an aluminum oxide layer provided on at least one side of the support (a), and (c) an interlayer applied onto the aluminum oxide layer comprising a hydrophilic polymer comprising structural units derived from the following compounds: (a1) at least one compound comprising both polyalkylene oxide chains and at least one structural unit which is free-radical polymerizable, and (a2) at least one monomer capable of copolymerizing with the free-radical polymerizable structural unit of (a1) and furthermore comprising at least one acidic functional group with pKs