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 imaging element for providing a lithographic printing late, comprising a lithographic base with a hydrophobic oleophilic surface and a top layer comprising a compound capable of converting light into heat and a hydrophilic polymer, characterized in that said hydrophilic polymer is crosslinked.
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.
摘要:
According to the present invention there is provided a method for making a lithographic printing plate comprising the steps of:providing an imaging element comprising on a support having a hydrophilic surface a photosensitive layer and a thermosensitive layer, said thermosensitive layer being opaque to light for which said photosensitive layer has spectral sensitivity and said thermosensitive layer comprising an infrared pigment dispersed in a binder;mounting said imaging element on a drum;image-wise exposing said imaging element by means of an infrared laser in an internal or external drum configuration thereby ablating said thermosensitive layer and rendering it image-wise transparent;overall exposing said imaging element with light to which said photosensitive layer has spectral sensitivity;developing said imaging element to leave an ink accepting image of said photosensitive layer on said support.
摘要:
The present invention provides a method for obtaining a lithographic printing plate comprising the steps of: (a) image-wise or information-wise exposing a photosensitive imaging element comprising on a hydrophilic surface of a support a hydrophobic photosensitive layer contiguous to said hydrophilic surface, comprising (i) a photosensitive acid precursor and (ii) a hydrophobic polymeric binder and (b) developing said exposed imaging element by the steps of: (i) laminating before or after said exposure an uppermost layer of said imaging element to a receptor layer and (ii) peeling away the receptor layer from the hydrophilic surface of the support thus transferring said hydrophobic photosensitive composition patternwise to the receptor layer, characterized in that said hydrophobic photosensitive layer comprises as photosensitive acid precursor a non-ionic photosensitive precursor of a sulphonic acid or a non-ionic photosensitive precursor of an optionally partially esterified phosphonic acid or a non-ionic photosensitive precursor of an optionally partially esterified phosphoric acid, the latter phosphonic or phosphoric acid precursors in the absence of an acid-sensitive composition of (a) low molecular weight compound(s).
摘要:
The present invention discloses a method for making a lithographic printing plate comprising the steps of: (1) image-wise exposing an imaging element having on a hydrophilic surface of a lithographic base a photosensitive layer comprising a photosensitive polymer containing aryl-diazosulfonate units; (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 photosensitive layer while rotating said print cylinder. Excellent printing results are obtained with a printing plate perpared according to the above described method. The lithographic base may be an anodized aluminium or a support provided with an ink-repellant layer containing a cross-linked hydrophilic binder.