摘要:
According to the present invention there is provided a method for obtaining a high quality printing plate by spraying a spray solution on a receiving surface, which is not a grained and anodized aluminum surface, characterized in that the pressure factor (PF) is lower than 200 mN/m, wherein PF=P/d×(&sgr;+&thgr; mN/m°) PF: Pressure Factor (mN/m) P: Spray Profile (mm) d: distance between spray head and receiving surface (mm) &sgr;: surface tension (mN/m). &thgr;: Dynamic contact angle of the receiving surface with water at 2 s, contact time, and wherein the spray solution comprises hydrophobic thermoplastic polymer particles and a compound capable of converting light into heat.
摘要:
According to the present invention there is provided a heat-sensitive material for making lithographic plates comprising in the order given on a support an IR-sensitive oleophilic layer and a cross-linked hydrophilic layer, wherein said heat-sensitive material is covered with a layer comprising at least an organic compound comprising cationic groups.
摘要:
According to the present invention there is provided a heat-sensitive material for making lithographic printing plates having on a lithographic support an image-forming layer including a hydrophilic binder, a cross-linking agent for the hydrophilic binder, metal oxide particles with a mean diameter of at least 100 nm and dispersed hydrophobic thermoplastic polymer particles, characterized in that the image-forming layer has a ratio of specific surface (in m2 per g) over mean roughness(in &mgr;m) of more than 0.65 and that the mean pore width is less than 15 nm.
摘要:
A method for making a lithographic printing master is disclosed. The method comprises a step of providing a hydrophilic cylindrical surface, e.g. an aluminium plate mounted on the plate cylinder of a printing press, with an image recording composition by transfer from a donor material. The donor material comprises a support and a transfer layer which comprises hydrophobic thermoplastic polymer particles dispersed in a hydrophilic binder and a compound capable of converting light to heat. The transfer is obtained by friction between the donor layer and the cylindrical surface and/or by moistening the cylindrical surface with an aqueous liquid. The method is especially suited for on-press coating and on-press imaging in computer-to-press procedures.
摘要:
According to the present invention there is provided a heat mode imaging element for making a lithographic printing plate having on a lithographic base with a hydrophilic surface a first layer including a polymer, soluble in an aqueous alkaline solution and a top layer on the same side of the lithographic base as the first layer which top layer is unpenetrable for or insoluble in an alkaline developer containing SiO.sub.2 in the form of silicates; characterized in that said first layer and said top layer comprise a compound capable of converting IR-light into heat.
摘要:
The present invention provides a method for making a lithographic printing plate comprising the steps of:(1) mounting an imaging element comprising (i) on a hydrophilic surface of a lithographic base an image forming layer comprising hydrophobic thermoplastic polymer particles capable of coalescing under the influence of heat and dispersed in a hydrophilic binder and (ii) a compound capable of converting light to heat, said compound being comprised in said image forming layer or a layer adjacent thereto on a print cylinder of a printing press;(2) image-wise exposing said imaging element by means of a laser or LED;(3) and developing a thus obtained image-wise exposed imaging element by supplying an aqueous dampening liquid and/or ink to said image forming layer while rotating said print cylinder.
摘要:
According to the present invention there is provided a method for making a lithographic printing plate comprising the image-wise exposure of a heat-sensitive imaging element with a laser and developing said imaging element by rinsing it with plain water or an aqueous solution. To improve ink-uptake the imaging element is exposed on an external drum recorder whereby the pixel dwell time of the laser is above 0.1 .mu.s
摘要:
Heat-sensitive imaging element for making positive working printing plates according to the present invention there is provided a heat-sensitive imaging element for making positive working lithographic printing plates comprising on a lithographic base a layer comprising a polymer, soluble in an aqueous alkaline solution and an IR-radiation sensitive top layer. Upon image-wise exposure the capacity of the aqueous alkaline solution to penetrate and/or solubilize the top layer is changed. Image-wise exposure can be performed with an infrared laser with a short as well as with a long pixel well time.The obtained positive working printing plates have excellent printing properties and an improved infrared sensitivity.
摘要:
The present invention provides a method for making a lithographic printing plate comprising the steps of:(1) image-wise exposing to light an imaging element comprising (i) on a hydrophilic surface of a lithographic base an image forming layer comprising hydrophobic thermoplastic polymer particles capable of coalescing under the influence of heat and dispersed in a hydrophilic binder and (ii) a compound capable of converting light to heat, said compound being comprised in said image forming layer or a layer adjacent thereto;(2) and developing a thus obtained image-wise exposed imaging element by mounting it on a print cylinder of a printing press and supplying an aqueous dampening liquid and/or ink to said image forming layer while rotating said print cylinder.
摘要:
A method is disclosed, and a corresponding thermal imaging medium for use with it, for the formation of an improved heat mode image comprising (A) exposing information-wise to laser radiation a thermal imaging medium comprising (1) a transparent support, (2) an image recording layer containing a hydrophilic binder, a substance capable of converting laser radiation into heat, and a dispersion of a hydrophobic polymer capable of undergoing thermocoagulation by the action of heat and having a built-in UV-absorber. A heat mode image with high density and improved resistance to physical damage is obtained.