摘要:
The present invention provides a lithographic base comprising on a hydrophobic support a packet of subbing layers contiguous to a hydrophilic layer containing a hydrophilic (co)polymer or (co)polymer mixture and being hardened with a hydrolysed tetraalkyl orthosilicate crosslinking agent characterized in that said packet of subbing layers contains as undermost layer a layer comprising, a polymer latex having hydrophilic functionality and as uppermost layer a layer comprising a hydrophilic binder and silica in a weight ratio of the hydrophilic binder to silica of less than 1.
摘要:
A method for making a lithographic printing plate includes the steps of providing a lithographic printing plate precursor including a support having a hydrophilic surface or which is provided with a hydrophilic layer, and a coating provided on the hydrophilic surface or the hydrophilic layer, wherein the coating includes an image recording layer including hydrophobic thermoplastic polymer particles and wherein the image recording layer or an optional other layer of the coating further includes an infrared light absorbing agent; image-wise exposing the precursor to infrared light having an energy density of 190 mJ/cm2 or less; developing the exposed precursor by removing unexposed areas in a processing liquid; baking the plate thus obtained by keeping the plate at a temperature above the glass transition temperature of the thermoplastic particles during a period between 5 seconds and 2 minutes.
摘要翻译:制备平版印刷版的方法包括以下步骤:提供包括具有亲水性表面的或具有亲水层的载体的平版印刷版原版和设置在亲水性表面或亲水层上的涂层,其中涂层 包括包含疏水性热塑性聚合物颗粒的图像记录层,并且其中所述图像记录层或所述涂层的任选的其它层还包括红外光吸收剂; 将前体成像地暴露于能量密度为190mJ / cm 2以下的红外光; 通过去除处理液体中的未曝光区域来显影所述暴露的前体; 通过在5秒至2分钟之间的时间内将板保持在高于热塑性颗粒的玻璃化转变温度的温度下烘烤由此获得的板。
摘要:
A method of making a heat-sensitive lithographic printing plate precursor is disclosed which comprises the steps of (i) providing a web of a lithographic support having a hydrophilic surface; (ii) coating a layer comprising a phenolic resin on the hydrophilic surface of the web; (iii) drying the layer; (iv) a heating step wherein the web temperature is maintained above 150° C. during a period of between 0.1 and 60 seconds; (v) winding the coated web on a core or cutting the coated web into sheets. The short on-line heating step provides a significant improvement of the aging behavior of the precursor. A stable sensitivity is obtained shortly after coating.
摘要:
A method is disclosed for removing ink-accepting areas from a printing master by laser ablation, characterized in that the printing master comprises a substrate which comprises a support and a base layer, wherein the base layer contains a crosslinked hydrophilic binder and a metal oxide. The base layer prevents deterioration of the quality of the substrate due to the laser ablation. In a preferred embodiment, the same substrate is used in a number of consecutive printing cycles of on-press coating, on-press exposure, printing and cleaning.
摘要:
A direct-to-plate method of lithographic printing is disclosed wherein a printing press is used that is coupled to a coating apparatus and to a cleaning apparatus; wherein the coating apparatus applies an image-recording layer on a substrate so as to obtain a printing plate, which is mechanically transferred to the printing press; and wherein, after the print job, the printing plate is mechanically transferred to the cleaning apparatus wherein the substrate is recycled, so that the recycled substrated can be reused in a next cycle of coating, printing and cleaning. The off-press coating and the off-press cleaning step provide a fully automated printing method wherein the press down-time is minimized. The method comprises also an off-press or an on-press exposure step.
摘要:
A method of making a heat-sensitive lithographic printing plate precursor is disclosed which comprises the steps of (i) providing a web of a lithographic support having a hydrophilic surface; (ii) applying on the hydrophilic surface of the web a coating comprising a phenolic resin; (iii) drying the coating by supplying heat to the coated web; (iv) a cooling step wherein the web temperature is reduced at an average cooling rate which is higher than if the web would be kept under ambient conditions but not higher than 30° C./s; and (v) winding the precursor on a core or cutting the precursor into sheets. The cooling step provides a significant improvement of the aging behavior of the precursor. A stable sensitivity is obtained shortly after coating.
摘要:
A method of making a heat-sensitive lithographic printing plate precursor is disclosed which comprises the steps of (i) providing a web of a lithographic support having a hydrophilic surface; (ii) applying on the hydrophilic surface of the web a coating comprising a phenolic resin; (iii) drying the coating; (iv) a heating step wherein the web temperature is maintained above the glass transition temperature of the phenolic resin Tg during a period of between 0.1 and 60 seconds; (v) a cooling step wherein the web temperature is reduced at an average cooling rate which is higher than if the web would be kept under ambient conditions but not higher than 30° C./s; and (vi) winding the precursor on a core or cutting the precursor into sheets. The heating step and the cooling step provide a significant improvement of the aging behavior of the precursor. A stable sensitivity is obtained shortly after coating.
摘要:
A method for making a lithographic printing plate is disclosed wherein the method comprises the steps of: (i) providing a lithographic printing plate precursor comprising a photosensitive coating on a substrate having a hydrophilic surface, (ii) image-wise exposing said photosensitive coating, (iii) developing said exposed coating to form an image on said substrate and optionally gumming the plate and (iv) baking the image on the plate, wherein said baking step is carried out within a dwell-time of less than 1 minute and wherein the chemical resistance of the coating against printing liquids and press chemicals is improved. This baking step is preferably carried out by exposing the printing plate to an infrared radiation source, preferably in a dynamic configuration.
摘要:
A direct-to-plate method of lithographic printing is disclosed which enables to recycle the lithographic substrate of the printing master. The method comprises the steps of (a) making a negative-working imaging material by coating on a hydrophilic substrate a coating solution comprising hydrophobic thermoplastic polymer particles and a hydrophilic binder; (b) making a printing master having ink-accepting areas by image-wise exposing the imaging material; (c) applying ink and fountain solution to the printing master; (d) removing the ink-accepting areas from the printing master by supplying a aliphatic or aromatic compound having a structure comprising at least 6 carbon atoms. The above steps are preferably carried out on-press.
摘要:
According to the present invention there is provided a lithographic base including a support and a hydrophilic cross-linked layer having a total volume of pores of more than 0.0007 cm3/g of the lithographic base. The hydrophilic cross-linked layer contains a hydrophilic binder, TiO2 particles and a low molecular weight polyhydric alcohol or a liquid amide as a drying control chemical additive.