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.
摘要:
A method for making a negative-working heat-sensitive lithographic printing plate precursor includes the steps pf: (i) providing a support having a hydrophilic surface or which is provided with a hydrophilic layer; and (ii) applying on the support a coating which includes a product DQ, wherein DQ is obtained by: the step of coating a solution or dispersion including a nucleophilic compound Q and a dye D selected from the list consisting of di- or tri-arylmethane dyes, cyanine dyes, styryl dyes, and merostyryl dyes; or by D and Q interact to form interaction product DQ, having a white light optical density which is lower that the white light optical density of dye D; and the interaction product DQ is capable of at least partially releasing a dye directly after exposure to infrared light or heat, therby forming a visible image in the coating.
摘要:
A positive-working lithographic printing plate precursor is disclosed which comprises (i) a grained and anodized aluminum support having a hydrophilic surface and (ii) a heat-sensitive oleophilic coating provided on the hydrophilic surface, wherein said coating is capable of dissolving in an aqueous alkaline developer at a higher dissolution rate in areas of said coating which are exposed to heat or infrared light than in unexposed areas, characterized in that the hydrophilic surface has a surface roughness, expressed as arithmetical mean center-line roughness Ra, which is less than 0.40 μm. The use of a low surface roughness as defined above provides an improved shelf life of the coating.
摘要:
According to the present invention there is provided a heat-sensitive imaging material for making lithographic printing plates which require no processing. The heat-sensitive imaging element comprises on a lithographic base having a hydrophilic surface a metallic or metal oxide layer and on top thereof an oleophobic oleophilic polymeric layer having a thickness of less than 5 &mgr;m and comprising a polymer containing phenolic groups.
摘要:
According to the present invention there is provided a heat mode imaging element for making a lithographic printing plate comprising 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 IR-sensitive and unpenetrable for an alkaline developer wherein said first layer and said top layer may be one and the same layer; characterized in that said top layer contains at least one blockcopolymer in an amount between 0.5 and 500 mg/m2.
摘要翻译:根据本发明,提供一种用于制造平版印刷版的热模式成像元件,该平版印刷版包括在具有亲水表面的平版印刷基底上,第一层包括可溶于碱性水溶液的聚合物和位于同一侧上的顶层 作为第一层的光刻基底,其顶层对于碱性显影剂是IR敏感的和不可穿透的,其中所述第一层和所述顶层可以是同一层; 其特征在于所述顶层含有至少一种0.5-500mg / m 2的嵌段共聚物。
摘要:
According to the present invention there is provided a heat ode imaging element for making a lithographic printing plate having n 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 IR-sensitive and unpenetrable or insoluble for an alkaline developer wherein said first layer and said top layer may be one and the same layer and said first layer and said top layer being the imaging layers; characterized in that said imaging layers have a glass transition temperature of at least 57° C.
摘要:
According to the present invention there is provided a method for the preparation of a lithographic printing plate comprising the steps of exposing with IR light an imaging element comprising 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 IR-sensitive and unpenetratable for or insoluble in an alkaline developer wherein said first layer and said top layer may be one and the same layer, said imaging element comprising a siloxane surfactant; developing said exposed imaging element with an alkaline solution; rinsing said developed imaging element with water or an aqueous solution; gumming said developed imaging element with a baking gum solution; subjecting said gummed imaging element to a thermal treatment at a temperature above 50° C.; characterized in that said rinsing is carried out with a brushing and/or with water containing a surfactant.
摘要:
According to the present invention there is provided a method for the preparation of a lithographic printing plate comprising the steps of exposing with IR light an imaging element comprising 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 IR-sensitive and unpenetratable for or insoluble in an alkaline developer wherein said first layer and said top layer may be one and the same layer, said imaging element comprising a siloxane surfactant; developing said exposed imaging element with an alkaline solution; gumming said developed imaging element with a baking gum solution; subjecting said gummed imaging element to a thermal treatment at a temperature above 50° C.; characterized in that said baking gum solution contains at least one surfactant making the contact angle between the baking gum solution and the surface of the plate less than 68° and/or at least one viscosity-regulating polymer making the viscosity of the baking gum solution between 1.7 cP and 5.0 cP.