摘要:
Processes for imaging and developing imageable elements useful as lithographic printing plate precursors either thermally or with ultraviolet radiation that use the same developer are disclosed. The imageable elements comprise a top layer and an underlayer. The top layer contains a phenolic polymer and a material that has either the o-benzoquinonediazide functionality or the o-diazonaphthoquinone functionality. The developer is a 20:80 to 80:20 mixture of (1) an aqueous alkaline developer that has a pH greater than 11 and contains about 2 wt% to about 8 wt% of an alkali metal silicate, and (2) a solvent based developer that contains about 0.5 wt% to about 15 wt% of an organic solvent or mixture of organic solvents.
摘要:
Vesicular images are formed by thermal imaging of imageable layers containing thermally imageable vesicular imaging compositions. The vesicular images can be used as masks for imaging printing plate precursors. In one aspect, the printing plate precursor is an assemblage comprising a flexible substrate; a photosensitive layer that contains a negative working photosensitive composition; an optional barrier layer; and the imageable layer. The imageable layer is thermally imaged to produce an integral mask. Blanket exposure through the mask with ultraviolet and/or visible radiation followed by development produces a printing plate. The method is especially suited for the production of flexographic printing plates.
摘要:
Multi-layer, positive working, thermally sensitive imageable elements useful as lithographic printing plate precursors, are disclosed. The elements comprises a substrate, an underlayer over the substrate, and a top layer over the underlayer. The top layer comprises either (a) a solvent soluble novolac resin that has a weight average molecular weight of at least 10,000, a derivative thereof functionalized with polar groups, or a derivative thereof functionalized with quadruple hydrogen bonding entities; (b) a solvent soluble m-cresol/p-cresol novolac resins that comprises at least 10 mol% p-cresol and has a weight average molecular weight of at least 8,000, a derivative thereof functionalized with polar groups, or a derivative thereof functionalized with quadruple hydrogen bonding entities; or (c) a mixture thereof. The imageable elements have increased scuff resistance and are thus less susceptible to damage during handling.
摘要:
Vesicular images are formed by thermal imaging of imageable layers containing thermally imageable vesicular imaging compositions. The vesicular images can be used as masks for imaging printing plate precursors. In one aspect, the printing plate precursor is an assemblage comprising a flexible substrate; a photosensitive layer that contains a negative working photosensitive composition; an optional barrier layer; and the imageable layer. The imageable layer is thermally imaged to produce an integral mask. Blanket exposure through the mask with ultraviolet and/or visible radiation followed by development produces a printing plate. The method is especially suited for the production of flexographic printing plates.
摘要:
Multilayer, positive working, thermally imageable, bakeable imageable elements are disclosed. The elements have a substrate, an underlayer, and a top layer. The underlayer comprises a polymeric material that comprises, in polymerized form about 5 mol% to about 30 mol% of methacrylic acid; about 20 mol% to about 75 mol% of N-phenylmaleimide, N-cyclohexylmaleimide, N-benzylmaleimide, or a mixture thereof; optionally, about 5 mol% to about 50 mol% of methacrylamide; and about 3 mol% to about 50 mol% of a compound represented by the formula: CH2C(R2)C(O)NHCH2OR1, in which R1 is C1 to C12 alkyl, phenyl, C1 to C12 substituted phenyl, C1 to C12 aralkyl, or Si(CH3)3; and R2 is H or methyl. Other materials, such as a resin or resins having activated methylol and/or activated alkylated methylol groups, such as a resole resin, may be present in the underlayer. The elements produce bakeable lithographic printing plates that are resistant to press chemistries.
摘要:
Sulfated polymers, imageable elements containing these polymers, and methods for preparing images useful as lithographic printing plates from these imageable elements are disclosed. The elements can be thermally imaged and developed in water or in fountain solution so that an alkaline developer is not required. They can be imaged and developed on press using fountain solution so that it is unnecessary to mount them in a separate exposure device.
摘要:
Multi-layer, positive working, thermally sensitive imageable elements useful as lithographic printing plate precursors, are disclosed. The elements comprises a substrate, an underlayer over the substrate, and a top layer over the underlayer. The top layer comprises either (a) a solvent soluble novolac resin that has a weight average molecular weight of at least 10,000, a derivative thereof functionalized with polar groups, or a derivative thereof functionalized with quadruple hydrogen bonding entities; (b) a solvent soluble m-cresol/p-cresol novolac resins that comprises at least 10 mol% p-cresol and has a weight average molecular weight of at least 8,000, a derivative thereof functionalized with polar groups, or a derivative thereof functionalized with quadruple hydrogen bonding entities; or (c) a mixture thereof. The imageable elements have increased scuff resistance and are thus less susceptible to damage during handling.