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EP0816070B1 - Elément d'enregistrement thermosensible et méthode pour la fabrication d'un cliché lithographique utilisant cet élément - Google Patents

Elément d'enregistrement thermosensible et méthode pour la fabrication d'un cliché lithographique utilisant cet élément Download PDF

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Publication number
EP0816070B1
EP0816070B1 EP19970201636 EP97201636A EP0816070B1 EP 0816070 B1 EP0816070 B1 EP 0816070B1 EP 19970201636 EP19970201636 EP 19970201636 EP 97201636 A EP97201636 A EP 97201636A EP 0816070 B1 EP0816070 B1 EP 0816070B1
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EP
European Patent Office
Prior art keywords
imaging element
layer
heat sensitive
image forming
lithographic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19970201636
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German (de)
English (en)
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EP0816070A1 (fr
Inventor
Joan Vermeersch
Marc Van Damme
Dirk Kokkelenberg
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Agfa Gevaert NV
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Agfa Gevaert NV
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Publication date
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Priority to EP19970201636 priority Critical patent/EP0816070B1/fr
Publication of EP0816070A1 publication Critical patent/EP0816070A1/fr
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Publication of EP0816070B1 publication Critical patent/EP0816070B1/fr
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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
    • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
    • B41M5/26—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used
    • B41M5/36—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using a polymeric layer, which may be particulate and which is deformed or structurally changed with modification of its' properties, e.g. of its' optical hydrophobic-hydrophilic, solubility or permeability properties
    • B41M5/366—Thermography ; Marking by high energetic means, e.g. laser otherwise than by burning, and characterised by the material used using a polymeric layer, which may be particulate and which is deformed or structurally changed with modification of its' properties, e.g. of its' optical hydrophobic-hydrophilic, solubility or permeability properties using materials comprising a polymeric matrix containing a polymeric particulate material, e.g. hydrophobic heat coalescing particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C1/00—Forme preparation
    • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
    • B41C1/1008—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials
    • B41C1/1025—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by removal or destruction of lithographic material on the lithographic support, e.g. by laser or spark ablation; by the use of materials rendered soluble or insoluble by heat exposure, e.g. by heat produced from a light to heat transforming system; by on-the-press exposure or on-the-press development, e.g. by the fountain of photolithographic materials using materials comprising a polymeric matrix containing a polymeric particulate material, e.g. hydrophobic heat coalescing particles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C2210/00—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation
    • B41C2210/04—Negative working, i.e. the non-exposed (non-imaged) areas are removed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C2210/00—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation
    • B41C2210/06—Developable by an alkaline solution
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C2210/00—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation
    • B41C2210/08—Developable by water or the fountain solution
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C2210/00—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation
    • B41C2210/24—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation characterised by a macromolecular compound or binder obtained by reactions involving carbon-to-carbon unsaturated bonds, e.g. acrylics, vinyl polymers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C2210/00—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation
    • B41C2210/26—Preparation or type or constituents of the imaging layers, in relation to lithographic printing forme preparation characterised by a macromolecular compound or binder obtained by reactions not involving carbon-to-carbon unsaturated bonds
    • B41C2210/262—Phenolic condensation polymers, e.g. novolacs, resols

Definitions

  • the present invention relates to a heat sensitive material for making a lithographic printing plate.
  • the present invention further relates to a method for preparing a printing plate from said heat sensitive material.
  • Lithography is the process of printing from specially prepared surfaces, some areas of which are capable of accepting lithographic ink, whereas other areas, when moistened with water, will not accept the ink.
  • the areas which accept ink form the printing image areas and the ink-rejecting areas form the background areas.
  • a photographic material is made imagewise receptive to oily or greasy ink in the photo-exposed (negative working) or in the non-exposed areas (positive working) on a hydrophilic background.
  • lithographic plates also called surface litho plates or planographic printing plates
  • a support that has affinity to water or obtains such affinity by chemical treatment is coated with a thin layer of a photosensitive composition.
  • Coatings for that purpose include light-sensitive polymer layers containing diazo compounds, dichromate-sensitized hydrophilic colloids and a large variety of synthetic photopolymers. Particularly diazo-sensitized systems are widely used.
  • the exposed image areas become insoluble and the unexposed areas remain soluble.
  • the plate is then developed with a suitable liquid to remove the diazonium salt or diazo resin in the unexposed areas.
  • WO 94/18005 discloses a heat mode recording material comprising on a support having an ink receptive surface a substance capable of convertibg light into heat and a hardened hydrophilic surface layer having a thickness not more than 3 ⁇ m.
  • EP-A 703,499 discloses a no-process printing plate having a protective top coat layer.
  • Said protective top coat layer may provide the no-processing plate with protection from contamination during handling.
  • EP-A 770,494, 770,495, 770,496 and 770,497 disclose a method for making a lithographic printing plate comprising the steps of (1) image-wise exposing to light a heat sensitive imaging element comprising (i) on a hydrophilic surface of a lithographic base an image forming layer comprising hydrophobic thermoplastic polymer particles 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 element by rinsing it with plain water.
  • FR 1,561,957 discloses an analogous material as mentioned above with the option that said material carries a surface layer. Neither the nature or the thickness of said surface layer is disclosed.
  • a heat sensitive imaging element comprising on a hydrophilic surface of a lithographic base an image forming layer including in a hydrophilic binder at least hydrophobic thermoplastic polymer particles for at least 20 % and a compound capable of converting light into heat, said compound being present in said image forming layer or a layer adjacent thereto, characterized in that on said image forming layer a covering layer is present having a thickness between 0.1 and 3 ⁇ m.
  • a method for obtaining a lithographic printing plate comprising the steps of:
  • lithographic printing plates of high quality especially with a high ink acceptance in the printing areas can be obtained according to the method of the present invention using an imaging element as described above. More precisely it has been found that said printing plates are of high quality and are provided in a convenient way, thereby offering economical and ecological advantages.
  • An imaging element for use in accordance with the present invention comprises on a hydrophilic surface of a lithographic base an image forming layer comprising at least hydrophobic thermoplastic polymer particles which is overcoated with a covering layer having a thickness between 0.1 and 5 ⁇ m.
  • Said covering layer can be a hydrophobic layer containing a hydrophobic polymer or copolymer such as polystyrene, polyolefinic compounds, poly(meth)acrylates, polyesters, copolymers of said polymers, etc..
  • a hydrophobic polymer or copolymer such as polystyrene, polyolefinic compounds, poly(meth)acrylates, polyesters, copolymers of said polymers, etc.
  • Said covering layer can be a water insoluble, alkali soluble or swellable layer containing a resin having phenolic hydroxy groups and/or carboxyl groups such as novolacs or polyvinyl phenols.
  • the covering layer used in connection with the present invention is a water soluble or swellable layer comprising hydrophilic polymers.
  • Suitable water soluble or swellable polymers for use in said covering layer in connection with this invention are for example synthetic homo or copolymers such as a polyvinyl alcohol, a poly(meth)acrylic acid, a poly(meth)acrylamide, a polyhydroxyethyl(meth)acrylate, a polyvinylmethylether, a polyvinyl pyrrolidone or natural binders such as gelatin, a polysaccharide such as e.g. dextran, pullulan, cellulose, arabic gum, alginic acid.
  • the thickness of said layer is preferably between 0.15 and 3 ⁇ m, more preferably between 0.2 and 2 ⁇ m.
  • the lithographic base can be an anodised aluminum support.
  • a particularly preferred lithographic base is an electrochemically grained and anodised aluminum support.
  • an anodised aluminum support may be treated to improve the hydrophilic properties of its surface.
  • the aluminum support may be silicated by treating its surface with sodium silicate solution at elevated temperature, e.g. 95°C.
  • a phosphate treatment may be applied which involves treating the aluminum oxide surface with a phosphate solution that may further contain an inorganic fluoride.
  • the aluminum oxide surface may be rinsed with a citric acid or citrate solution.
  • This treatment may be carried out at room temperature or can be carried out at a slightly elevated temperature of about 30 to 50°C.
  • a further interesting treatment involves rinsing the aluminum oxide surface with a bicarbonate solution. It is further evident that one or more of these post treatments may be carried out alone or in combination.
  • the lithographic base comprises a flexible support, such as e.g. paper or plastic film, provided with a cross-linked hydrophilic layer.
  • a particularly suitable cross-linked hydrophilic layer may be obtained from a hydrophilic binder cross-linked with a cross-linking agent such as formaldehyde, glyoxal, polyisocyanate or a hydrolysed tetra-alkylorthosilicate. The latter is particularly preferred.
  • hydrophilic binder there may be used hydrophilic (co)polymers such as for example, homopolymers and copolymers of vinyl alcohol, acrylamide, methylol acrylamide, methylol methacrylamide, acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate or maleic anhydride/vinylmethylether copolymers.
  • the hydrophilicity of the (co)polymer or (co)polymer mixture used is preferably the same as or higher than the hydrophilicity of polyvinyl acetate hydrolyzed to at least an extent of 60 percent by weight, preferably 80 percent by weight.
  • the amount of crosslinking agent, in particular of tetraalkyl orthosilicate, is preferably at least 0.2 parts by weight per part by weight of hydrophilic binder, preferably between 0.5 and 5 parts by weight, more preferably between 1.0 parts by weight and 3 parts by weight.
  • a cross-linked hydrophilic layer in a lithographic base used in accordance with the present embodiment preferably also contains substances that increase the mechanical strength and the porosity of the layer.
  • colloidal silica may be used.
  • the colloidal silica employed may be in the form of any commercially available water-dispersion of colloidal silica for example having an average particle size up to 40 nm, e.g. 20 nm.
  • inert particles of larger size than the colloidal silica can be added e.g. silica prepared according to Stöber as described in J. Colloid and Interface Sci., Vol.
  • alumina particles or particles having an average diameter of at least 100 nm which are particles of titanium dioxide or other heavy metal oxides.
  • the thickness of a cross-linked hydrophilic layer in a lithographic base in accordance with this embodiment may vary in the range of 0.2 to 25 ⁇ m and is preferably 1 to 10 ⁇ m.
  • cross-linked hydrophilic layers for use in accordance with the present invention are disclosed in EP-A 601240, GB-P-1419512, FR-P-2300354, US-P-3971660, US-P-4284705 and EP-A 514490.
  • plastic film e.g. substrated polyethylene terephthalate film, cellulose acetate film, polystyrene film, polycarbonate film etc.
  • the plastic film support may be opaque or transparent.
  • the amount of silica in the adhesion improving layer is between 200 mg per m 2 and 750 mg per m 2 .
  • the ratio of silica to hydrophilic binder is preferably more than 1 and the surface area of the colloidal silica is preferably at least 300 m 2 per gram, more preferably at least 500 m 2 per gram.
  • an image forming layer on top of a hydrophilic surface there is provided an image forming layer.
  • an image forming layer in connection with the present invention comprises at least thermoplastic polymer particles. Said thermoplastic polymer particles are dispersed in a hydrophylic binder.
  • the hydrophilic binder can be a water insoluble, alkali soluble or swellable resin having phenolic hydroxy groups and/or carboxyl groups.
  • the water insoluble, alkali soluble or swellable resin used in connection with the present invention comprises phenolic hydroxy groups.
  • Suitable water insoluble, alkali soluble or swellable resins for use in an image forming layer in connection with this invention are for example synthetic novolac resins such as ALNOVOL, a registered trade mark of Reichold Hoechst and DUREZ, a registered trade mark of OxyChem and synthetic polyvinylfenols such as MARUKA LYNCUR M, a registered trade mark of Dyna Cyanamid.
  • the hydrophilic binder is preferably a water soluble or swellable hydrophilic polymer.
  • Suitable water soluble or swellable polymers for use in an image forming layer in connection with this invention are for example synthetic homo or copolymers such as a polyvinyl alcohol, a poly(meth)acrylic acid, a poly(meth)acrylamide, a polyhydroxyethyl(meth)acrylate, a polyvinylmethylether, a polyvinyl pyrrolidone or natural binders such as gelatin, a polysaccharide such as e.g. dextran, pullulan, cellulose, arabic gum, alginic acid.
  • the hydrophilic binder used in connection with the present invention is preferably not cross-linked or only slightly cross-linked.
  • Hydrophobic thermoplastic polymer particles used in connection with the present invention preferably have a coagulation temperature above 35°C and more preferably above 50°C. Coagulation may result from softening or melting of the thermoplastic polymer particles under the influence of heat. There is no specific upper limit to the coagulation temperature of the thermoplastic hydrophobic polymer particles, however the temperature should be sufficiently below the decomposition of the polymer particles. Preferably the coagulation temperature is at least 10°C below the temperature at which the decomposition of the polymer particles occurs.
  • said polymer particles When said polymer particles are subjected to a temperature above coagulation temperature they coagulate to form a hydrophobic agglomerate in the hydrophilic layer so that at these parts the hydrophilic layer becomes insoluble in plain water or an aqueous liquid.
  • hydrophobic polymer particles for use in connection with the present invention are e.g. polyethylene, polyvinyl chloride, polymethyl (meth)acrylate, polyethyl (meth)acrylate, polyvinylidene chloride, polyacrylonitrile, polyvinyl carbazole etc. or copolymers thereof. Most preferably used is polyethylene or polymethyl methacrylate.
  • the weight average molecular weight of the polymers may range from 5,000 to 1,000,000g/mol.
  • the hydrophobic particles may have a particle size from 0.01 ⁇ m to 50 ⁇ m, more preferably between 0.05 ⁇ m and 10 ⁇ m and most preferably between 0.05 ⁇ m and 2 ⁇ m.
  • the polymer particles are present as a dispersion in the aqueous coating liquid of the image forming layer and may be prepared by the methods disclosed in US-P-3,476,937. Another method especially suitable for preparing an aqueous dispersion of the thermoplastic polymer particles comprises:
  • the amount of hydrophobic thermoplastic polymer particles contained in the image forming layer is between 20% by weight and 65% by weight and preferably between 25% by weight and 55% by weight and most preferably between 30% by weight and 45% by weight.
  • the image forming layer can also comprise crosslinking agents although this is not necessary.
  • Preferred crosslinking agents are low molecular weight substances comprising a methylol group such as for example melamine-formaldehyde resins, glycoluril-formaldehyde resins, thiourea-formaldehyde resins, guanamine-formaldehyde resins, benzoguanamine-formaldehyde resins.
  • a number of said melamine-formaldehyde resins and glycoluril-formaldehyde resins are commercially available under the trade names of CYMEL (Dyno Cyanamid Co., Ltd.) and NIKALAC (Sanwa Chemical Co., Ltd.).
  • the image forming layer has preferably a thickness between 0.1 and 3 ⁇ m, more preferably between 0.15 and 2 ⁇ m, most preferably between 0.2 and 1 ⁇ m.
  • Suitable compounds capable of converting light into heat are preferably infrared absorbing components although the wavelength of absorption is not of particular importance as long as the absorption of the compound used is in the wavelength range of the light source used for image-wise exposure.
  • Particularly useful compounds are for example dyes and in particular infrared dyes, carbon black, metal carbides, borides, nitrides, carbonitrides, bronze-structured oxides and oxides structurally related to the bronze family but lacking the A component e.g. WO 2.9 .
  • conductive polymer dispersion such as polypyrrole or polyaniline-based conductive polymer dispersions.
  • the lithographic performance and in particular the print endurance obtained depends on the heat-sensitivity of the imaging element. In this respect it has been found that carbon black yields very good and favorable results.
  • a light to heat converting compound in connection with the present invention is most preferably added to the image forming layer but at least part of the light to heat converting compound may also be comprised in a neighbouring layer.
  • Such layer can be for example the cross-linked hydrophilic layer of the lithographic base according to the second embodiment of lithographic bases explained above.
  • the imaging element is image-wise exposed and subsequently developed with an aqueous solution.
  • Image-wise exposure in connection with the present invention is preferably an image-wise scanning exposure involving the use of a laser or L.E.D.. It is highly preferred in connection with the present invention to use a laser emitting in the infrared (IR) and/or near-infrared, i.e. emitting in the wavelength range 700-1500nm. Particularly preferred for use in connection with the present invention are laser diodes emitting in the near-infrared.
  • IR infrared
  • near-infrared i.e. emitting in the wavelength range 700-1500nm.
  • laser diodes emitting in the near-infrared are particularly preferred for use in connection with the present invention.
  • the hydrophilic binder in the image forming layer of the imaging element is a water insoluble, alkali soluble or swellable resin having phenolic hydroxy groups and/or carboxyl groups
  • the developing liquid is an alkaline solution, preferably with a pH between 9 and 14, more preferably with a pH between 10 and 13.
  • the developing solution may be plain water.
  • the exposed imaging element is rubbed with e.g. an absorbent means or a brush during the application of the developing liquid or while still being wet with the developing solution or is sprayed with the developing solution.
  • the obtained plate After the development of an image-wise exposed imaging element with an aqueous solution and drying the obtained plate can be used as a printing plate as such. However, it is still possible to bake said plate at a temperature between 100°C and 230°C for a period of 40 minutes to 5 minutes.
  • the exposed and developed plates can be baked at a temperature of 230°C for 5 minutes, at a temperature of 150°C for 10 minutes or at a temperature of 120°C for 30 minutes.
  • the printing plate can be used in the printing process as a seamless sleeve printing plate.
  • the printing plate is soldered in a cylindrical form by means of a laser.
  • This cylindrical printing plate which has as diameter the diameter of the print cylinder is slided on the print cylinder instead of applying in a classical way a classically formed printing plate. More details on sleeves is given in "Grafisch Niews" , 15, 1995, page 4 to 6.
  • the imaging element is image-wise exposed and subsequently mounted on a print cylinder of a printing press.
  • the printing press is then started and while the print cylinder with the imaging element mounted thereon rotates, the dampener rollers that supply dampening liquid are dropped on the imaging element and subsequently thereto the ink rollers are dropped.
  • the dampener rollers that supply dampening liquid are dropped on the imaging element and subsequently thereto the ink rollers are dropped.
  • the first clear and useful prints are obtained.
  • the ink rollers and dampener rollers may be dropped simultaneously or the ink droppers may be dropped first.
  • the exposed imaging element may be converted to a seamless sleeve imaging element before mounting the exposed imaging element on the print cylinder.
  • Suitable dampening solutions that can be used in connection with the present invention are aqueous liquids generally having an acidic pH and comprising an alcohol such as isopropanol.
  • dampening liquids useful in the present invention there is no particular limitation and commercially available dampening liquids, also known as fountain solutions, can be used.
  • the imaging element is first mounted on the print cylinder of the printing press and then image-wise exposed directly on the press. Subsequent to exposure, the imaging element can be developed as described above.
  • the unexposed imaging element may be converted to a seamless sleeve imaging element before mounting the unexposed imaging element on the print cylinder.
  • a 0.15 mm thick aluminum foil was degreased by immersing the foil in an aqueous solution containing 5 g/l of sodium hydroxide at 50°C and rinsed with demineralized water.
  • the foil was then electrochemically grained using an alternating current in an aqueous solution containing 4 g/l of hydrochloric acid, 4 g/l of hydroboric acid and 5 g/l of aluminum ions at a temperature of 35°C and a current density of 1200 A/m 2 to form a surface topography with an average center-line roughness Ra of 0.5 ⁇ m.
  • the aluminum foil was then etched with an aqueous solution containing 300 g/l of sulfuric acid at 60°C for 180 seconds and rinsed with demineralized water at 25°C for 30 seconds.
  • the foil was subsequently subjected to anodic oxidation in an aqueous solution containing 200 g/l of sulfuric acid at a temperature of 45°C, a voltage of about 10 V and a current density of 150 A/m 2 for about 300 seconds to form an anodic oxidation film of 3.00 g/m 2 of Al 2 O 3 , then washed with demineralized water, posttreated with a solution containing 20 g/l of sodium bicarbonate at 40°C for 30 seconds, subsequently rinsed with demineralized water at 20°C during 120 seconds and dried.
  • the grained and anodized lithographic base was then submersed in an aqueous solution containing 5 % w/w of citric acid for 60 seconds, brought at pH 7 with an aqueous solution of sodium hydroxyde 2N for 60 seconds, rinsed with demineralized water and dried at 25°C.
  • An imaging element according to the invention was produced by preparing the above described coating composition for the infrared recording layer, coating it onto the above described lithographic base in an amount of 30 g/m 2 (wet coating amount) and drying it at 36°C.
  • Imaging element II was prepared in an identical way as imaging element I with the exception that on top of the recording layer a covering layer from the above described coating solution I was coated in an amount of 30 g/m 2 (wet coating amount) and dried at room temperature.
  • Imaging element III was prepared in an identical way as imaging element I with the exception that on top of the recording layer a covering layer from the above described coating solution II was coated in an amount of 30 g/m 2 (wet coating amount) and dried at room temperature.
  • the imaging elements I, II and III were subjected to a scanning infra-red laser diode emitting at 830 nm (scanspeed 1 m/s, spot size 10 ⁇ m and the power on the plate surface was 120 mW ). After imaging the plates were processed with plain water.
  • the ablation on said plates is the ratio on an exposed non-processed imaging element of the optical reflection density of an unexposed area (maximum density) versus the optical reflection density of an exposed area (image density). The results are given in table 1.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Thermal Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Printing Plates And Materials Therefor (AREA)
  • Photosensitive Polymer And Photoresist Processing (AREA)

Claims (9)

  1. Elément de formation d'image thermosensible comprenant, sur une surface hydrophile d'une base lithographique, une couche de formation d'image englobant, dans un liant hydrophile, au moins des particules polymères thermoplastiques hydrophobes en une quantité entre 20 et 65% en poids et un composé capable de transformer de la lumière en chaleur, ledit composé étant présent dans ladite couche de formation d'image ou dans une couche adjacente à cette dernière, caractérisé en ce que, sur ladite couche de formation d'image, est présente une couche de recouvrement possédant une épaisseur entre 0,1 et 3 µm.
  2. Elément de formation d'image thermosensible selon la revendication 1, dans lequel ladite couche de recouvrement est une couche soluble ou apte à gonfler dans l'eau, comprenant un polymère hydrophile.
  3. Élément de formation d'image thermosensible selon la revendication 1, dans lequel ledit liant hydrophile de la couche de formation d'image est un polymère soluble ou apte à gonfler dans l'eau.
  4. Élément de formation d'image thermosensible selon l'une quelconque des revendications 1 à 3, dans lequel ladite base lithographique est de l'aluminium anodisé ou comprend un support flexible sur lequel est appliquée une couche hydrophile réticulée.
  5. Élément de formation d'image thermosensible selon l'une quelconque des revendications 1 à 4, dans lequel ledit composé capable de transformer de la lumière en chaleur est un membre choisi parmi le groupe constitué par un colorant absorbant l'infrarouge, du noir de carbone, un borure métallique, un carbure métallique, un nitrure métallique, un carbonitrure métallique et une dispersion polymère conductrice.
  6. Élément de formation d'image thermosensible selon l'une quelconque des revendications 1 à 5, dans lequel ledit élément de formation d'image thermosensible est un élément de formation d'image thermosensible en forme de manchon sans soudure.
  7. Procédé pour obtenir un cliché d'impression lithographique, comprenant les étapes consistant à:
    (a) exposer en forme d'image ou en forme d'information à de la lumière ou à de la chaleur, un élément de formation d'image selon l'une quelconque des revendications 1 à 6;
    (b) développer ledit élément de formation d'image exposé, avec une solution développatrice aqueuse dans le but d'éliminer les zones non exposées et d'obtenir ainsi un cliché d'impression lithographique.
  8. Procédé pour obtenir un cliché lithographique selon la revendication 7, dans lequel ledit liant hydrophile de la couche de formation d'image est un polymère soluble ou apte à gonfler dans l'eau et dans lequel ledit élément de formation d'image exposé en forme d'image est développé en le montant sur un cylindre d'impression d'une presse d'impression et en alimentant une solution de mouillage aqueuse et/ou de l'encre à ladite couche de formation d'image, tout en faisant tourner ledit cylindre d'impression.
  9. Procédé pour obtenir un cliché lithographique selon la revendication 7 ou 8, dans lequel ledit cliché d'impression lithographique est un cliché d'impression en forme de manchon sans soudure.
EP19970201636 1996-06-24 1997-06-03 Elément d'enregistrement thermosensible et méthode pour la fabrication d'un cliché lithographique utilisant cet élément Expired - Lifetime EP0816070B1 (fr)

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EP19970201636 EP0816070B1 (fr) 1996-06-24 1997-06-03 Elément d'enregistrement thermosensible et méthode pour la fabrication d'un cliché lithographique utilisant cet élément

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EP96201754 1996-06-24
EP96201754 1996-06-24
EP19970201636 EP0816070B1 (fr) 1996-06-24 1997-06-03 Elément d'enregistrement thermosensible et méthode pour la fabrication d'un cliché lithographique utilisant cet élément

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EP0816070A1 EP0816070A1 (fr) 1998-01-07
EP0816070B1 true EP0816070B1 (fr) 2000-10-18

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US6838226B2 (en) 2003-05-20 2005-01-04 Eastman Kodak Company Imaging member with microgel protective layer
US6899996B2 (en) 2003-05-20 2005-05-31 Eastman Kodak Company Method of preparing imaging member with microgel protective layer
EP1142707B2 (fr) † 2000-04-07 2011-11-30 FUJIFILM Corporation Précurseur de plaque d'impression lithographique sensible à la chaleur

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GB9709404D0 (en) * 1997-05-10 1997-07-02 Du Pont Uk Improvements in or relating to the formation of images
EP1065049B1 (fr) * 1999-06-29 2004-11-10 Agfa-Gevaert Elément formateur d'image sensible à la chaleur avec une couche protectrice pour la fabrication de plaques d'impression lithographiques
US6503684B1 (en) 1999-06-29 2003-01-07 Agfa-Gevaert Processless thermal printing plate with cover layer containing compounds with cationic groups
JP2001162960A (ja) * 1999-12-06 2001-06-19 Fuji Photo Film Co Ltd 感熱性平版印刷版用原板
JP2001166459A (ja) 1999-12-06 2001-06-22 Fuji Photo Film Co Ltd 感熱性平版印刷用原板
JP2001183816A (ja) * 1999-12-27 2001-07-06 Fuji Photo Film Co Ltd ネガ型感熱性平版印刷用原板
US7592128B2 (en) 2001-04-04 2009-09-22 Eastman Kodak Company On-press developable negative-working imageable elements
US6582882B2 (en) 2001-04-04 2003-06-24 Kodak Polychrome Graphics Llc Imageable element comprising graft polymer
US6899994B2 (en) 2001-04-04 2005-05-31 Kodak Polychrome Graphics Llc On-press developable IR sensitive printing plates using binder resins having polyethylene oxide segments
US6551757B1 (en) 2001-05-24 2003-04-22 Eastman Kodak Company Negative-working thermal imaging member and methods of imaging and printing
EP1586461B1 (fr) 2001-07-23 2008-03-05 FUJIFILM Corporation Précurseur de plaque d'impression lithographique
EP1524112B1 (fr) 2003-10-16 2007-12-12 Agfa Graphics N.V. Précurseur thermosensible pour plaque lithographique
US7297467B2 (en) 2003-10-16 2007-11-20 Agfa Graphics Nv Method of making a heat-sensitive lithographic printing plate
EP1524113B1 (fr) 2003-10-16 2010-03-24 Agfa Graphics N.V. Procédé de fabrication d'une plaque lithographique thermosensible
US7425405B2 (en) * 2004-07-08 2008-09-16 Agfa Graphics, N.V. Method for making a lithographic printing plate
US7195861B2 (en) * 2004-07-08 2007-03-27 Agfa-Gevaert Method for making a negative working, heat-sensitive lithographic printing plate precursor
US7354696B2 (en) * 2004-07-08 2008-04-08 Agfa Graphics Nv Method for making a lithographic printing plate
EP3960456B1 (fr) * 2018-01-31 2025-06-18 FUJIFILM Corporation Précurseur de plaque d'impression lithographique et procédé de préparation de plaque d'impression lithographique

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GB1208414A (en) * 1966-10-24 1970-10-14 Agfa Gevaert Nv Improvements relating to thermo recording
FR1552000A (fr) * 1967-10-20 1969-01-03
JPS5935797B2 (ja) * 1980-12-17 1984-08-30 コニカ株式会社 感熱記録材料
WO1994018005A1 (fr) * 1993-02-09 1994-08-18 Agfa-Gevaert Naamloze Vennootschap Matiere d'enregistrement en mode thermique et procede l'utilisant dans la fabrication d'une plaque d'impression lithographique
US5506090A (en) * 1994-09-23 1996-04-09 Minnesota Mining And Manufacturing Company Process for making shoot and run printing plates

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1142707B2 (fr) † 2000-04-07 2011-11-30 FUJIFILM Corporation Précurseur de plaque d'impression lithographique sensible à la chaleur
US6838226B2 (en) 2003-05-20 2005-01-04 Eastman Kodak Company Imaging member with microgel protective layer
US6899996B2 (en) 2003-05-20 2005-05-31 Eastman Kodak Company Method of preparing imaging member with microgel protective layer

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