摘要:
The present invention relates to negative-working imageable elements that can be used for the manufacture of printing plates. These imageable elements can be developed on on-press by the action of a lithographic printing ink used in combination with either water or a fountain solution. The imageable elements comprise an imageable layer that is not removable in water or fountain solution alone. The imageable layer includes a free radically polymerizable compound, a free radical initiator composition, an infrared radiation absorbing compound, and a polymeric binder comprising poly(alkylene oxide) pendant groups, and preferably additionally pendant cyano groups.
摘要:
A method of preparing negative-working, single-layer imageable elements improves their storage stability in a humid environment. The method includes enclosing the coated imageable elements in a water-impermeable sheet material that substantially inhibits the transfer of moisture to and from the imageable element. Such imageable elements include a radiation-sensitive composition that includes a radically polymerizable component, an initiator composition to provide radicals upon exposure to imaging radiation, a radiation absorbing compound, and a polymeric binder having poly(alkylene glycol) side chains.
摘要:
The present invention relates to negative-working imageable elements that can be used for the manufacture of printing plates. These imageable elements can be developed on on-press by the action of a lithographic printing ink used in combination with either water or a fountain solution. The imageable elements comprise an imageable layer that is not removable in water or fountain solution alone. The imageable layer includes a free radically polymerizable compound, a free radical initiator composition, an infrared radiation absorbing compound, and a polymeric binder comprising poly(alkylene oxide) pendant groups, and preferably additionally pendant cyano groups.
摘要:
Infrared absorbing compounds in which the anion is selected from the group consisting of 5-isatinsulfonate, 10-camphorsulfonate, and 4,5-dihydroxy-1,3-benzenedisulfonate are disclosed. Negative-working imageable elements containing these compounds have improved dot stability.
摘要:
A radiation-sensitive composition and negative-working imagable element includes a polymeric binder that has a hydrophobic backbone and pendant salt groups that comprise a cation covalently attached to the hydrophobic backbone and a boron-containing anion forming a salt with the cation. The use of these particular polymers provides fast digital speed (high imaging sensitivity) and good printability (good shelf-life) even when the preheat step normally used between exposure and development, is omitted.
摘要:
A method for forming images useful as lithographic printing plate precursors is disclosed. An imageable element in which the imageable layer comprises an acid generator, a crosslinking agent, and a binder is imaged with ultraviolet radiation and developed with a solvent based developer. The acid generator is an iodonium, sulfonium, or diazonium salt in which the anion is an organic sulfate or thiosulfate anion. The binder comprises a copolymer that contains a reactive pendent group capable of undergoing acid crosslinking, in which the reactive pendent group is hydroxyl, carboxylic acid, sulfonamide, alkoxymethyl, or a mixture thereof. The method is especially suited for use with direct digital ultraviolet imaging devices. The resulting image is useful as a lithographic printing plate.
摘要:
A radiation-sensitive composition and negative-working imageable element includes a polymeric binder that has a hydrophobic backbone and pendant salt groups that comprise a cation covalently attached to the hydrophobic backbone and a boron-containing anion forming a salt with the cation. The use of these particular polymers provides fast digital speed (high imaging sensitivity) and good printability (good shelf-life) even when the preheat step normally used between exposure and development, is omitted.
摘要:
A negative-working imageable element has an imageable layer that includes an initiator composition including an iodonium cation and a boron-containing anion at a molar ratio of at least 1.2:1, an infrared radiation absorbing compound, a primary polymeric binder, and a spirolactone or spirolactam colorant precursor. The imaged element exhibits improved print-out.
摘要:
A positive-working imageable element comprises inner and outer layers and a radiation absorbing compound such as an IR absorbing dye. The inner layer includes a polymeric material that is removable using an alkaline developer. An ink receptive outer layer is not removable using an alkaline developer before its exposure to imaging radiation. The outer layer includes a polymer binder having pendant epoxy groups that are substantially unreacted during exposure.
摘要:
A method for forming a printing plate from a printing plate precursor having a radiation-sensitive layer, sensitive to radiation in a first frequency spectrum such as the far or near infrared, and to radiation in a second frequency spectrum other than the first frequency spectrum such as visible or ultraviolet. The plate is exposed twice. Once to imaging radiation in the first frequency spectrum and again to radiation in the second frequency spectrum. The second frequency spectrum exposure is done only to the areas of the plate undesirably shaded during the imagewise exposure.