Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H18/00—Winding webs
  • B65H18/28—Wound package of webs
• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41N—PRINTING PLATES OR FOILS; MATERIALS FOR SURFACES USED IN PRINTING MACHINES FOR PRINTING, INKING, DAMPING, OR THE LIKE; PREPARING SUCH SURFACES FOR USE AND CONSERVING THEM
  • B41N1/00—Printing plates or foils; Materials therefor
  • B41N1/006—Printing plates or foils; Materials therefor made entirely of inorganic materials other than natural stone or metals, e.g. ceramics, carbide materials, ferroelectric materials
• • 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
• • 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
  • B41C1/1016—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 characterised by structural details, e.g. protective layers, backcoat layers or several imaging layers
• • 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
  • B41C1/1041—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme by modification of the lithographic properties without removal or addition of material, e.g. by the mere generation of a lithographic pattern
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C2201/00—Location, type or constituents of the non-imaging layers in lithographic printing formes
  • B41C2201/04—Intermediate layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
  • B41C2201/00—Location, type or constituents of the non-imaging layers in lithographic printing formes
  • B41C2201/14—Location, type or constituents of the non-imaging layers in lithographic printing formes characterised by macromolecular organic compounds, e.g. binder, adhesives
• • 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
  • B41C2210/02—Positive working, i.e. the exposed (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
  • B41C2210/04—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
  • B41C2210/16—Waterless working, i.e. ink repelling exposed (imaged) or non-exposed (non-imaged) areas, not requiring fountain solution or water, e.g. dry lithography or driography
• • 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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2301/00—Handling processes for sheets or webs
  • B65H2301/40—Type of handling process
  • B65H2301/41—Winding, unwinding
  • B65H2301/412—Roll
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2515/00—Physical entities not provided for in groups B65H2511/00 or B65H2513/00
  • B65H2515/30—Forces; Stresses
  • B65H2515/37—Elasticity modulus
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2701/00—Handled material; Storage means
  • B65H2701/10—Handled articles or webs
  • B65H2701/17—Nature of material

Definitions

• This invention relates to a material for producing a lithographic printing plate comprising a thin glass support.
• Lithographic printing is the process of printing from specially prepared surfaces, some areas of which are capable of accepting ink (oleophilic areas) whereas other areas will not accept ink (oleophobic areas).
• the oleophilic areas form the printing areas while the oleophobic areas form the background areas.
• lithographic printing plates Two basic types of lithographic printing plates are known. According to a first type, so called wet printing plates, both water or an aqueous dampening liquid and ink are applied to the plate surface that contains hydrophilic and hydrophobic areas. The hydrophilic areas will be soaked with water or the dampening liquid and are thereby rendered oleophobic while the hydrophobic areas will accept the ink.
• a second type of lithographic printing plates operates without the use of a dampening liquid and are called driographic printing plates. This type of printing plates comprise highly ink repellant areas and oleophilic areas. Generally the highly ink repellant areas are formed by a silicon layer.
• Common supports for use in lithographic printing plates are e.g. metal supports in particular grained and anodised aluminium or supports comprising a substrate such as e.g. paper or plastic film provided with a hydrophilic layer, preferably a hydrophilic layer that is cross-linked.
• lithographic printing plate could have such a support. Since different types of lithographic plate precursors, i.e. materials making it possible to produce a lithographic printing plates, are known in the art it is desirable to have a glass support that is useful for all types of lithographic printing plate precursors.
• DTR diffusion transfer
• the objects of the invention are realized by providing a material for making a lithographic printing plate comprising on a glass support a surface capable of being differentiated in ink accepting and ink repellant areas in accordance with an image pattern, characterised in that said glass support has a thickness of not more than 0.5 mm, a failure stress of at least 10 7 Pa, a Youngs modulus of not more than 10 11 Pa and rounded edges.
• said glass has moreover a failure stress (under tensile stress) equal to or higher than 1 x 10 7 Pa, preferably higher than 4 x 10 7 Pa, it is even easier to present it in roll form.
• a failure stress under tensile stress
• the glass can, depending on the thickness, be presented on rolls wound upon a core, said core having a diameter between 0.1 m and 3 m.
• the glass support when the glass support is thinner than 1.2 mm, has an elasticity modulus (Young's modulus) lower than 10 x 10 10 Pa, preferably lower than 7 x 10 10 Pa, and a failure stress (under tensile stress) higher than 4 x 10 7 Pa, it can, depending on the thickness, be presented on rolls wound upon a core having a diameter between 0.1 m and 1.6 m.
• Young's modulus Young's modulus
• the glass support has an elasticity modulus (Young's modulus) lower than 10 x 10 10 Pa, preferably lower than 7 x 10 10 Pa, and a failure stress (under tensile stress) higher than 4 x 10 7 Pa, and is not more than 0.8 mm tick, it can be presented on rolls wound upon a core having a diameter between 0.1 m and 1.2 m.
• Young's modulus Young's modulus
• the glass support according to the invention shoukd have rounded edges. Every glass-coating technique yields a relatively undefined edge. This edge is practically always cut away, so that an edge with a right angle is obtained. It has been found that said edge is a potential initiator for micro-cracks and break. It has further been found that a rounded edge does not have said disadvantages.
• the radius of said rounded edge is preferably not higher than the half of the thickness of said glass support.
• the glass support For use as support in a lithographic printing plate precursor, i.e. a material for the production of lithographic printing plates, the glass support should be less than 0.5 mm thick.
• a material for making a lithographic printing plate having a surface capable of being differentiated in ink accepting and ink repellant areas in accordance with an image pattern, on a glass support and being flexible.
• the glass support for such a material was preferably less than 0.5 mm thick, had a failure stress of at least 10 7 Pa and a Youngs modulus of not more than 10 11 Pa.
• the material further comprises a hydrophilic layer formed of a cross-linked hydrophilic polymer.
• 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 cross-linking 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 accordance with the present invention 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. 26, 1968, pages 62 to 69 or 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 surface of the cross-linked hydrophilic layer is given a uniform rough texture consisting of microscopic hills and valleys, which serve as storage places for water in background areas.
• the thickness of a cross-linked hydrophilic layer 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.
• a very suitable material for making lithographic printing plates is a material comprising on a glass support a surface capable of being differentiated in ink accepting and ink repellant areas in accordance with an image pattern, characterised in that
• More preferred materials for making a lithographic printing plate are materials comprising on a glass support a surface capable of being differentiated in ink accepting and ink repellant areas in accordance with an image pattern, characterised in that
• a photosensitive layer in accordance with the present invention may comprise any suitable light-sensitive composition from which an ink accepting image on the hydrophilic surface of the support of the imaging element can be obtained.
• suitable light-sensitive compositions used herein are those comprising diazo compounds; those comprising azide compounds as disclosed in U.K. Patent Nos. 1,235,281 and 1,495,861; those containing photo-cross-linkable photopolymers as disclosed in U.S. Patent Nos. 4,072,528 and 4,072,527 and in particular those described in more detail below.
• these light-sensitive compositions preferably used are those comprising diazo compounds since they are synthetically excellent in various properties such as storage properties of the photosensitive layer; developability, for instance, development latitude; image properties, e.g. quality of images; printing properties, e.g., ink receptivity and wear resistance; and low possibility of causing environmental pollution of developers used.
• the light-sensitive compositions containing diazo compounds can roughly be divided in two groups, i.e. negative-working type and positive-working type ones.
• the negative-working light-sensitive compositions containing diazo compounds comprise light-sensitive diazo compounds and preferably polymeric compounds.
• the light-sensitive diazo compounds there may be used any ones conventionally known and preferred examples thereof are salts of organic solvent-soluble diazo resins such as salts of condensates of p-diazodiphenylamine and formaldehyde or acetaldehyde with hexafluorophosphates and salts thereof with 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid salts.
• examples of the foregoing polymeric compounds preferably used are copolymers of acrylic acid or methacrylic acid; crotonic acid copolymers; itaconic acid copolymers, maleic acid copolymers, cellulose derivatives having carboxyl groups on the side chains thereof, polyvinyl alcohol derivatives having carboxyl groups on the side chains thereof, copolymers of hydroxyalkyl (meth)acrylate having carboxyl groups on the side chains thereof, and unsaturated polyester resins having carboxyl groups.
• any compounds conventionally known may be utilized and typical examples thereof are o-quinonediazides and preferably o-naphthoquinonediazide compounds. Particularly preferred are o-naphthoquinonediazidosulfonic acid esters or o-naphthoquinone diazidocarboxylic acid esters of various hydroxyl compounds; and o-naphthoquinonediazidosulfonic acid amides or o-naphthoquinonediazidocarboxylic acid amides of various aromatic amine compounds.
• phenols include phenol, cresol, resorcin and pyrogallol
• carbonyl group-containing compounds are formaldehyde, benzaldehyde and acetone
• preferred hydroxyl compounds include phenol-formaldehyde resin, cresol-formaldehyde resin, pyrogallol-acetone resin and resorcin-benzaldehyde resin.
• o-quinonediazide compounds include esters of benzoquinone-(1,2)-diazidosulfonic acid or napthoquinone-(1,2)-diazidosulfonic acid and phenol-formaldehyde resin or cresol-formaldehyde resin; ester of naphthoquinone-(1,2)-diazido-(2)-5-sulfonic acid and pyrogallol-acetone resin as disclosed in U.S. Patent No.
• Examples of other useful o-quinonediazide compounds are polyesters having hydroxyl groups at their termini esterified with o-napthoquinonediazidesulfonyl chloride as disclosed in J.P. KOKAI No. Sho 50-117503; homopolymers of p-hydroxystyrene or copolymers thereof with other copolymerizable monomers esterified with o-naphtoquinonediazidosulfonyl chloride as disclosed in J.P. KOKAI No. Sho 50-113305; ester of bisphenol-formaldehyde resin and o-quinonediazidosulfonic acid as disclosed in J.P. KOKAI No.
• o-quinonediazide compounds may be used alone, but are preferably used as a mixture with an alkalki-soluble resin to form a light-sensitive layer.
• Preferred alkali-soluble resins include novolak type phenol and typical examples thereof are phenolformaldehyde, cresol-formaldehyde resin, and phenol-cresol-formaldehyde copolycondensed resins as disclosed in J.P. KOKAI No. Sho 55-57841. More preferably, the foregoing phenol resins are simultaneously used with a condensate of phenol or cresol substituted with an alkyl group having 3 to 8 carbon atoms and formaldehyde such as t-butylphenol-formaldehyde, as described in J.P. KOKAI No. Sho 50-125806.
• alkali-soluble polymers other than the above listed alkali-soluble novolak phenolic resins.
• alkali-soluble polymers other than the above listed alkali-soluble novolak phenolic resins.
• examples of such polymers are styrene-acrylic acid copolymer, methyl methacrylate-methacrylic acid copolymer, alkali-soluble polyurethane resin, and alkali-soluble vinylic resins and alkali-soluble polybutyral resins as disclosed in J.P. KOKOKU No. Sho 52-28401.
• the amount of the o-quinonediazide compounds is preferably 5 to 80 % by weight and more preferably 10 to 50 % by weight based on the total weight of the solid contents of the light-sensitive composition.
• that of the alkali-soluble resins is preferably 30 to 90 % by weight and more preferably 50 to 85 % by weight based on the total weight of the solid contents of the light-sensitive composition.
• a photosensitive layer in connection with this invention may be applied in the form of a multilayered structure.
• the light-sensitive composition in the photosensitive layer or multi-layer package may further comprise optional components such as dyes, plasticizers and components for imparting printing-out properties (ability of providing a visible image immediately after imagewise exposure).
• the coated amount of a photosensitive layer applied onto the hydrophilic surface of a support preferably ranges from 0.1 to 7 g/m 2 and more preferably 0.5 to 4 g/m 2 .
• Preferred photo-cross-linking materials in the present invention are based on photo-cross-linking polymers having a maleimido group at their side chain.
• photosensitivity sensitisers such as thioxanthones, benzophenone, Michler's ketone, anthraquinones, anthracene, chrysene, p-dinitrobenzene, 2-nitrofluorene, as well as sensitizers described in JP-A-62-294238, JP-A-2-173646, JP-A-2-236552, JP-A-3-54566 and JP-A-6-107718.
• JP-A as used herein means an "unexamined published Japanese patent application”.
• a photo-cross-linking polymer having a maleimido group at its side chain(s) includes, for example polymers that are described in U.S. Patent 4,079,041 (corresponding to JP-A-52-988); West German Patent 2,626,769; European Patents 21,019 and 3,552; Die Angewandte Makromolekulare Chemie, 115 (1983), pp.
• JP-A-49-128991 to JP-A-49-128993 JP-A-50-5376 to JP-A-50-5380, JP-A-53-5298 to JP-A-53-5300, JP-A-50-50107, JP-A-51-47940, JP-A-52-13907, JP-A-50-45076, JP-A-52-121700, JP-A-50-10844, JP-A-50-45087, JP-A-58-43951; West German Patents 2,349,948 and 2,616,276.
• those having, at their side chains, two or more maleimido groups on average in one molecule and having a mean molecular weight of 1000 or more are preferably used in the present invention.
• An imaging element containing any of these polymers is preferably developed with an aqueous alkaline developer substantially not containing an organic solvent, in view of the environmental safety. Therefore, it is preferable that these polymers are soluble in or swellable with aqueous alkalis. Accordingly, it is preferably that monomers having a maleimido group at its side chain are copolymerized with monomers having a alkali-soluble group to obtain these polymers.
• alkali-soluble group preferred are acid groups having a pKa of 14 or less.
• monomers having an alkali-soluble group include vinyl monomers having a carboxyl group, such as acrylic acid, methacrylic acid, maleic acid, itaconic acid; vinyl monomers having a -CONHSO 2 -group; vinyl monomers having an - SO 2 NH-group; vinyl monomers having a phenolic hydroxyl group; vinyl monomers having a phosphoric acid group or a phosphonic acid group; as well as maleic anhydride, and itaconic anhydride.
• vinyl monomers having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid, itaconic acid
• vinyl monomers having a -CONHSO 2 -group vinyl monomers having an - SO 2 NH-group
• vinyl monomers having a phenolic hydroxyl group vinyl monomers having a phosphoric acid group or a phosphonic acid group
• maleic anhydride and it
• the alkali-soluble group having monomer and the maleido group having monomer are generally copolymerized at a ratio of from 10/90 to 70/30 by mol, preferably from 20/80 to 60/40 by mol, to easily give a photo-cross-linking polymer for use in the present invention.
• the polymer has preferably an acid value of from 30 to 500, especially preferably from 50 to 300.
• photo-cross-linking polymers especially useful are copolymers composed of an N-[2-methacryloyloxy)alkyl]-2,3-dimethylmaleimide and methacrylic acid or acrylic acid, such as those described in Die Angewandte Makromolekulare Chemie, 128 (1984), pp. 71-91.
• vinyl monomers may additionally copolymerized, as the third component, to easily give polynary copolymers as desired.
• alkyl methacrylates or alkyl acrylates of which homopolymers have a glass transition temperature not higher than room temperature can be copolymerized as the third component to give flexible copolymers.
• a photo-cross-linking polymer for use in the present invention has preferably a weight average molecular weight of 1000 or more, more preferably from 10,000 to 500,000, and even more preferably from 20,000 to 300,000.
• a sensitizer to a photosensitive layer having a photo-cross-linkable polymer as described above.
• Preferred is a triplet sensitizer having an absorption peak for ensuring sufficient light absorption at 300 nm or more.
• sensitizer examples include benzophenone derivatives, bezanthrone derivatives, quinones, aromatic nitro compounds, naphthothiazoline derivatives, benzothiazoline derivatives, thioxanthones, naphthothiazole derivatives, ketocoumarin compounds, benzothiazole derivatives, naphthofranone compounds, pyrylium salts, and thiapyrylium salts.
• sensitizers described in JP-A-2-236552, JP-A-3-54566 and JP-A-6-107718 are preferred; and especially preferred are the sensitizers having one or more of -COOH, -NHSO 2 R 20 , -CONHCOR 20 and/or -CONHSO 2 R 20 (where R 20 represents an alkyl group, an aromatic group or an alkyl-aromatic group) as an alkali-soluble group in one molecule, described in JP-A-6-107718.
• the amount of sensitizer in the photosensitive layer is conveniently from 1 to 20 % by weight, preferably from 2 to 15 % by weight, and more preferably from 3 to 10 % by weight, of the total amount of the compositions in the photosensitive layer.
• diazo resins include co-condensates composed of aromatic diazonium compounds and aldehydes. Specific examples thereof include the diazo resins described in JP-B-49-48001, JP-B-50-7481, JP-B-5-2227, JP-A-3-2864, JP-A-3-240061, and JP-A-4-274429.
• diazo resins having a carboxyl group in the molecule for example, diazo resins obtained by co-condensation with aromatic compounds having at least one carboxyl group, such as those described in JP-A-3-240061, and diazo resins obtained by condensation with aldehydes having a caboxyl group, such as those described in JP-A-2864.
• the amount of the diazo resin in the photosensitive layer is preferably from 0.1 to 30 % by weight, preferably from 0.5 to 10 % by weight, and more preferably from 1 to 5 % by weight of the total amount of the compositions in the photosensitive layer.
• polymer having one or more polymerisable groups such as the polymers disclosed in JP-B-3-63740, U.S. Patents 3,376,138, 3,556,793.
• the above-mentioned polymer having one or more polymerisable groups is preferably soluble in or swellable with aqueous alkaline developers, like the polymers having a maleimido group at the side chain. Therefore, this polymer is preferably a copolymer composed of one or more monomers having an alkali-soluble group, e.g. as mentioned above.
• the material for making the lithographic printing plate is a DTR (diffusion transfer material), both in a two-sheet and in a mono-sheet process.
• DTR diffusion transfer material
• a sheet material comprising a silver halide material is image wise exposed and then contacted with a second sheet material, according to the present invention, comprising an image receiving layer with physical development nuclei.
• the sandwich of the two sheets is then processed and during this processing silver ions migrate to the image receiving layer and are precipitated on the physical development nuclei.
• a mono-sheet DTR process both the silver halide layer and the image receiving layer are present in the same sheet material.
• the image receiving layer comprising physical development nuclei is provided on a glass support according to the present invention.
• Said glass support is first provided with a layer comprising a cross-linked hydrophilic polymer and on this hydrophilic polymer layer, a layer comprising physical development nuclei is provided, forming an image receiving layer.
• This image receiving layer is then used in a two-sheet DTR process.
• a substance is image-wise transferred to the surface of said material thereby differentiating said surface in ink accepting and ink repellant areas in accordance with the image pattern being transferred.
• the image receiving layer containing physical development nuclei is preferably free of hydrophilic binder but may comprise small amounts upto 30% by weight of the total weight of said layer of a hydrophilic colloid e.g. polyvinyl alcohol to improve the hydrophilicity of the surface.
• a hydrophilic colloid e.g. polyvinyl alcohol to improve the hydrophilicity of the surface.
• Preferred development nuclei for use in accordance with the present invention are sulphides of heavy metals e.g. sulphides of antimony. bismuth, cadmium, cobalt, lead, nickel, palladium, platinum, silver, and zinc.
• Especially suitable development nuclei in connection with the present invention are palladium sulphide nuclei.
• Other suitable development nuclei are salts such as e.g. selenides, polyselenides, polysulphides, mercaptans, and tin (II) halides.
• Heavy metals, preferably silver, gold, platinum, palladium, and mercury can be used in colloidal form.
• the glass support according to the present invention is also well suited for the production of a monosheet DTR material.
• a mono-sheet DTR material for producing a lithographic printing plate can be implemented in two forms.
• a DTR mono-sheet material for the production of a lithographic printing plate comprises a glass support, according to the present invention, and in the order given i) a hydrophilic polymer layer, which can optionally be cross-linked, ii) an image receiving layer comprising physical development nuclei and iii) a silver halide photographic emulsion layer.
• a DTR mono-sheet material for the production of a lithiographic printing plate comprises a glass support, according to the present invention, and in the order given i) a silver halide photographic emulsion layer and ii) an image receiving layer comprising physical development nuclei.
• the hydrophilic polymer layer useful in the first embodiment of a DTR mono-sheet material for the production of a lithographic printing plate can be a hydrophilic polymer layer as described herein above.
• the image receiving layer comprising physical development nuclei useful in a mono-sheet DTR material, according to this invention, can be the same as the image receiving layers described herein above.
• the support of this sheet material is a glass support according to this invention.
• an image receiving layer is provided with a photosensitive layer in water permeable contact with said image receiving layer.
• Layers being in waterpermeable contact with each other are layers that are contiguous to each other or only separated from each other by (a) waterpermeable layer(s).
• the nature of a waterpermeable layer is such that it does not substantially inhibit or restrain the diffusion of water or of compounds contained in an aqueous solution e.g. developing agents or the complexed silver.
• the photosensitive material used both in a mono-sheet DTR process and in a two-sheet DTR process, with a material for making lithographic printing plates according to the present invention can be any layer comprising a hydrophilic colloid binder and at least one silver halide emulsion, at least one of the silver halide emulsions being photosensitive.
• the photographic silver halide emulsion(s) used in accordance with the present invention can be prepared from soluble silver salts and soluble halides according to different methods as described e.g. by P. Glafkides in "Chimie et Physique Photographique", Paul Montel, Paris (1967), by G.F. Duffin in “Photographic Emulsion Chemistry", The Focal Press, London (1966), and by V.L. Zelikman et al in “Making and Coating Photographic Emulsion", The Focal Press, London (1966).
• the silver halide emulsion or emulsions preferably consist principally of silver chloride while a fraction of silver bromide may be present ranging from 1 mole % to 40 mole %. Most preferably a silver halide emulsion containing at least 70 mole% of silver chloride is used.
• the average size of the silver halide grains may range from 0.10 to 0.70 ⁇ m , preferably from 0.25 to 0.45 ⁇ m.
• iridium and/or rhodium containing compounds or a mixture of both are added.
• concentration of these added compounds ranges from 10 -8 to 10 -3 mole per mole of AgNO 3 , preferably between 10 -7 and 10 -5 mole per mole of AgNO 3 .
• the emulsions can be chemically sensitized e.g. by adding sulphur-containing compounds during the chemical ripening stage e.g. allyl isothiocyanate, allyl thiourea, and sodium thiosulphate.
• reducing agents e.g. the tin compounds described in BE-P 493,464 and 568,687, and polyamines such as diethylene triamine or derivatives of aminomethane-sulphonic acid can be used as chemical sensitizers.
• Other suitable chemical sensitizers are noble metals and noble metal compounds such as gold, platinum, palladium, iridium, ruthenium and rhodium. This method of chemical sensitization has been described in the article of R.KOSLOWSKY, Z. Wiss. Photogr. Photophys. Photochem. 46, 65-72 (1951).
• Suitable direct positive silver halide emulsions for use in accordance with the present invention are silver halide emulsions that have been previously fogged or that mainly form an internal latent image.
• the other type of direct positive type silver halide emulsions for use in accordance with the present invention which is of the previously fogged type, may be prepared by overall exposing a silver halide emulsion to light and/or by chemically fogging a silver halide emulsion.
• Chemical fog specks may be formed by various methods for chemical sensitization.
• Chemical fogging may be carried out by reduction or by a compound which is more electropositive than silver e.g. gold salts, platinum salts, iridium salts etc., or a combination of both.
• Reduction fogging of the silver halide grains may occur by high pH and/or low pAg silver halide precipitation or digestion conditions e.g. as described by Wood J. Phot. Sci. 1 (1953), 163 or by treatment with reducing agents e.g.
• tin (II) salts which include tin(II)chloride, tin complexes and tin chelates of (poly)amino(poly)carboxylic acid type as described in British Patent 1,209,050 , formaldehyde, hydrazine, hydroxylamine, sulphur compounds e.g. thiourea dioxide, phosphonium salts e.g. tetra(hydroxymethyl)-phosphonium chloride, polyamines e.g. diethylenetriamine, bis(p-aminoethyl)sulphide and its water-soluble salts, hydrazine derivatives, alkali arsenite, amine borane etc. or mixtures thereof.
• tin (II) salts which include tin(II)chloride, tin complexes and tin chelates of (poly)amino(poly)carboxylic acid type as described in British Patent 1,209,
• the reducing agent e.g. thiourea dioxide and a compound of a metal more electropositive than silver especially a gold compound
• the reducing agent is preferably used initially and the gold compound subsequently.
• the reverse order can be used or both compounds can be used simultaneously.
• chemical fogging can be attained by using said fogging agents in combination with a sulphur-containing sensitizer, e.g. sodium thiosulphate or a thiocyanic acid compound e.g. potassium thiocyanate.
• a sulphur-containing sensitizer e.g. sodium thiosulphate or a thiocyanic acid compound e.g. potassium thiocyanate.
• the silver halide emulsions of the DTR-element can be spectrally sensitized according to the spectral emission of the exposure source for which the DTR element is designed.
• Suitable sensitizing dyes for the visible spectral region include methine dyes such as those described by F.M. Hamer in "The Cyanine Dyes and Related Compounds", 1964, John Wiley & Sons. Dyes that can be used for this purpose include cyanine dyes, merocyanine dyes, complex cyanine dyes, complex merocyanine dyes, homopolar cyanine dyes, hemicyanine dyes, styryl dyes and hemioxonol dyes. Particularly valuable dyes are those belonging to the cyanine dyes, merocyanine dyes, complex merocyanine dyes.
• a green sensitizing dye is needed.
• a blue sensitizing dye is incorporated.
• a red sensitizing dye is used.
• a semiconductor laser special spectral sensitizing dyes suited for the near infra-red are required. Suitable infra-red sensitizing dyes are disclosed in i.a. US-P 2,095,854, 2,095,856, 2,955,939, 3,482,978, 3,552,974, 3,573,921, 3,582,344, 3,623,881 and 3,695,888.
• a preferred blue sensitizing dye, green sensitizing dye, red sensitizing dye and infra-red sensitizing dye in connection with the present invention are described in EP-A 554,585.
• supersensitizers in combination with red or infra-red sensitizing dyes.
• Suitable supersensitizers are described in Research Disclosure Vol 289, May 1988, item 28952.
• the spectral sensitizers can be added to the photographic emulsions in the form of an aqueous solution, a solution in an organic solvent or in the form of a dispersion.
• the silver halide emulsions may contain the usual emulsion stabilizers.
• Suitable emulsion stabilizers are azaindenes, preferably tetra- or penta-azaindenes, especially those substituted with hydroxy or amino groups. Compounds of this kind have been described by BIRR in Z. Wiss. Photogr. Photophys. Photochem. 47, 2-27 (1952).
• Other suitable emulsion stabilizers are i.a. heterocyclic mercapto compounds.
• the silver halide emulsion layers usually contains gelatin as hydrophilic colloid binder. Mixtures of different gelatins with different viscosities can be used to adjust the rheological properties of the layer. But instead of or together with gelatin, use can be made of one or more other natural and/or synthetic hydrophilic colloids, e.g. albumin, casein, zein, polyvinyl alcohol, alginic acids or salts thereof, cellulose derivatives such as carboxymethyl cellulose, modified gelatin, e.g. phthaloyl gelatin etc.
• gelatin as hydrophilic colloid binder. Mixtures of different gelatins with different viscosities can be used to adjust the rheological properties of the layer. But instead of or together with gelatin, use can be made of one or more other natural and/or synthetic hydrophilic colloids, e.g. albumin, casein, zein, polyvinyl alcohol, alginic acids or salts thereof, cellulose derivatives such as carboxymethyl cellulose,
• the material for making a lithographic printing plate is a mono-sheet DTR material comprising a glass support, according to the present invention, and in the order given i) a hydrophilic polymer layer, which can optionally be cross-linked, ii) an image receiving layer comprising physical development nuclei and iii) a silver halide photographic emulsion layer preferably the gelatin layer(s) is(are) substantially unhardened.
• substantially unhardened means that when such gelatin layer is coated on a subbed polyethylene terephthalate film base at a dry thickness of 1.2 g/m 2 , dried for 3 days at 57 C° and 35% R.H. and dipped in water of 30 C°, said gelatin layer is dissolved for more than 95 % by weight within 5 minutes.
• the silver halide emulsions may contain pH controlling ingredients.
• at least one gelatin containing layer is coated at a pH value not below the iso-electric point of the gelatin to avoid interactions between said gelatin containing layer and another (optional) layer.
• Most preferably all the gelatin containing layers are coated at a pH value not below the iso-electric point of their gelatin.
• Other ingredients such as antifogging agents, development accelerators, wetting agents, and hardening agents for gelatin may be present.
• the silver halide emulsion layer may comprise light-screening dyes that absorb scattering light and thus promote the image sharpness. Suitable light-absorbing dyes are described in i.a. US-P 4,092,168, US-P 4,311,787 and DE-P 2,453,217.
• compositions, preparation and coating of silver halide emulsions suitable for use in accordance with the present invention can be found in e.g. Product Licensing Index, Vol. 92, December 1971, publication 9232, p. 107-109.
• the material for making a lithographic printing plate is a mono-sheet DTR material comprising a glass support, according to the present invention, and in the order given i) a hydrophilic polymer layer, which can optionally be cross-linked, ii) an image receiving layer comprising physical development nuclei and iii) a silver halide photographic emulsion layer, the material preferably also comprises an intermediate layer between the image receiving layer on the hydrophilic surface of a support and the photosensitive layer(packet) to facilitate the removal of said layer(packet) thereby uncovering the silver image formed in the image receiving layer by processing the imaging element.
• the intermediate layer is a water-swellable intermediate layer coated at a ratio of 0.01 to 2.0 g/m 2 and comprising at least one non-proteinic hydrophilic film-forming polymer e.g. polyvinyl alcohol and optionally comprising an antihalation dye or pigment as disclosed in EP-A-410500.
• non-proteinic hydrophilic film-forming polymer e.g. polyvinyl alcohol and optionally comprising an antihalation dye or pigment as disclosed in EP-A-410500.
• the intermediate layer is a layer comprising hydrophobic polymer beads having an average diameter not lower than 0.2 ⁇ m and having been prepared by polymerization of at least one ethylenically unsaturated monomer.
• said intermediate layer in dry condition comprises said hydrophobic polymer beads in an amount of up to 80% of its total weight. Further details are disclosed in EP-A-483415.
• a supplemental intermediate layer which may be present between said silver halide emulsion containing layer and said water-swellable intermediate layer or said intermediate layer comprising hydrophobic polymer beads may incorporate one or more ingredients such as i.a. antihalation dyes or pigment, developing agents, silver halide solvents, base precursors, and anticorrosion substances.
• a driographic material for the production of a lithographic printing plate comprsies a glass support, said glass support being at most 0.5 mm thick and having a failure stress of at least 10 7 Pa and a Youngs modulus of not more than 10 11 Pa.
• driographic materials as described in EP-A 573 091, that is incorporated herein by reference.
• the main advantage of these driographic materials is the fact that the need for the use of an organic solvent in the development is avoided or that at least ecollogically more acceptable solvents can be used.
• the driographic material comprsing a glass support is a heat-mode recording material.
• a material is image-able by laser ablation and comprises on said glass support a first layer comprising a polymer and a second layer underlying said first layer, at least one of said first and second layer being characterised by efficient absorption of infrared radiation and said first and second layers exhibiting different affinities for a printing fluid selected from the group consisting of ink and an abhesive fluid for ink.
• this material comprises in said first layer a polysiloxane and is oleophobic.
• said first layer of said driographic material comprises a conductive polymer layer, an infrared absorbing metal layer or an infrared absorbing compound dispersed in a polymeric binder.
• the heat converting substance is contained in the oleophobic surface layer.
• the heat mode recording material contains a separate heat mode recording layer containing the heat converting substance comprised between the glass support and an oleophobic surface layer.
• substances capable of converting radiation into heat are e.g. carbon black, infrared or near infrared absorbing dyes or pigments, metals such as Bi, Sn, Te etc. or a combination thereof. Suitable infrared dyes are disclosed in e.g.
• Suitable infrared pigments are e.g. HEUCODOR metal oxide pigments available from Heubach Langelsheim.
• the recording layer is preferably a vacuum deposited metal layer.
• the thickness of the recording layer may not be more than 3 ⁇ m in order to obtain a printing plate of acceptable quality, more preferably the thickness will be less than 2.5 ⁇ m.
• the recording layer preferably has a thickness between 15 nm and 1.5 ⁇ m. The maximum thickness of 3 ⁇ m of the recording layer is especially important when exposure is carried out through the support.
• the heat mode recording layer used in connection with the present invention may contain a binder e.g. gelatin, cellulose, cellulose esters e.g.
• the recording layer may further contain other ingredients such as e.g. wetting agents, matting agents, anti-oxidizing agents etc..
• the heat mode recording layer contains a polymer containing covalently bound chlorine. Alternatively part or all of this polymer may be contained in a separate layer located adjacent to the heat mode recording layer and most preferably between the support and the heat mode recording layer.
• the heat mode recording layer in connection with the present invention may be hardened.
• nitrocellulose layer hardened with an isocyanate may be used. It has been found that when a polymer containing covalently bound chlorine is contained in the heat mode recording layer of a recording material or in an adjacent layer the speed of the recording material can be improved.
• the oleophobic surface layer in accordance with the present invention preferably has a thickness of at least 1.0 ⁇ m and more preferably at least 1.5 ⁇ m.
• the maximum thickness of the surface layer is not critical but will preferably be not more than 5 ⁇ m and more preferably not more than 4 ⁇ m. It has been found that the thickness of the oleophobic surface layer influences the printing endurance, sharpness and resolution of the printing plate.
• the oleophobic surface layer preferably contains a hardened silicone coating.
• the silicone coating contains one or more components one of which is generally a linear silicone polymer terminated with a chemically reactive group at both ends and a multifunctional component as a hardening agent.
• the silicone coating can be hardened by condensation curing, addition curing or radiation curing.
• Condensation curing can be performed by using a hydroxy terminated polysiloxane that can be cured with a multifunctional silane.
• Suitable silanes are e.g. acetoxy silanes, alkoxy silanes and silanes containing oxime functional groups.
• the condensation curing is carried out in the presence of one or more catalyst such as e.g. tin salts or titanates.
• hydroxy terminated polysiloxanes can be cured with a polyhydrosiloxane polymer in the presence of a catalyst e.g. dibutyltindiacetate.
• Addition curing is based on the addition of Si-H to a double bond in the presence of a platinum catalyst.
• Silicone coatings that can be cured according to the addition curing thus comprise a vinyl group containing polymer, a platinum catalyst e.g. chloroplatinic acid complexes and a polyhydrosiloxane e.g. polymethylhydrosiloxane.
• Suitable vinyl group containing polymers are e.g. vinyldimethyl terminated polydimethylsiloxanes and dimethylsiloxane/vinylmethyl siloxane copolymers.
• Radiation cure coatings that can be used in accordance with the present invention are e.g. U.V. curable coatings containing polysiloxane polymers containing epoxy groups or electron beam curable coatings containing polysiloxane polymers containing (meth)acrylate groups.
• the latter coatings preferably also contain multifunctional (meth)acrylate monomers.

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• 1997
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