Classifications

• • 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
  • B41N3/00—Preparing for use and conserving printing surfaces
  • B41N3/03—Chemical or electrical pretreatment
  • B41N3/036—Chemical or electrical pretreatment characterised by the presence of a polymeric hydrophilic coating
• • 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
  • 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
  • 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
  • B41C2210/24—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

Definitions

• the invention relates to plate, film or ribbon-shaped support materials for offset printing plates based on aluminum with a hydrophilic coating, a process for the production of these materials and the use of the materials in the production of offset printing plates.
• Backing materials for offset printing plates are provided either by the consumer directly or by the manufacturer of precoated printing plates on one or both sides with a light-sensitive layer (copying layer), with the aid of which a printing image is generated photomechanically.
• the support carries the printing image areas and at the same time forms the hydrophilic background for the lithographic printing process in the non-image areas (non-image areas).
• Aluminum, steel, copper, brass or zinc, but also plastic films or paper can be used as the base material for such layers. These raw materials are processed by suitable operations such as. B. Grain, chrome plating, superficial oxidation and / or application of an intermediate layer are converted into substrates for offset printing plates.
• Aluminum, the base material probably used most frequently today for offset printing plates, rockenbürstung by known methods by T, superficially roughened wet brushing, sandblasting, chemical and / or electrochemical treatment.
• the roughened substrate can also be subjected to an anodization step to build up a thin oxide layer.
• the use of salts of these compounds is also mentioned, but is not specified in detail.
• DE-AS 10 91 433 discloses the hydrophilization of printing plate support materials based on metals with film-forming organic polymers such as polymethacrylic acid or sodium carboxymethyl cellulose or hydroxyethyl cellulose in the case of aluminum supports or a mixed polymer of methyl vinyl ether and maleic anhydride in the case of magnesium supports.
• film-forming organic polymers such as polymethacrylic acid or sodium carboxymethyl cellulose or hydroxyethyl cellulose in the case of aluminum supports or a mixed polymer of methyl vinyl ether and maleic anhydride in the case of magnesium supports.
• water-soluble polyfunctional amino-urea-aldehyde synthetic resins or sulfonated urea-aldehyde synthetic resins are first used, which are in a water-insoluble state on the metal support be cured.
• the hydrophilic layer on a printing plate support material according to DE-PS 21 07 901 is formed from a water-insoluble hydrophilic acrylate or methacrylate homopolymer or copolymer with a water absorption of at least 20% by weight.
• the layer weight of the hydrophilic adhesive layer on cellulose ether is 0.2 to 1.1 mg / dm 2 , and the same layer weight is also given for the water-soluble salts.
• the mixture of cellulose ether and salt is applied to the support in aqueous solution, optionally with the addition of an organic solvent and / or a surfactant.
• hydrophilizing agents for printing plate support materials according to US Pat. No. 4,049,746 contain salt-like reaction products from water-soluble polyacrylic resins with carboxyl groups and polyalkyleneimine-urea-aldehyde resins.
• hydrophilic colloids such as hydroxyethyl cellulose, polyacrylamide, polyethylene oxide, polyvinyl pyrrolidone, starch or gum arabic are described as hydrophilizing agents for anodized aluminum printing plate supports.
• the object of the invention is therefore to modify the hydrophilicity of support materials for offset printing plates in such a way that they are equally suitable as supports for positive, negative or electrophotographic light-sensitive layers without the aforementioned disadvantages of known modification methods occurring.
• the water-soluble polymers used to prepare the complex-type reaction products are in particular polyacrylic acid, a copolymer based on polyacrylic acid, polyacrylamide, a copolymer based on polyacrylamide, a hydrolyzed or partially or completely subjected to ammonolysis with NH 3 based on ethylene or vinyl methyl ether and maleic anhydride or carboxyalkyl cellulose (with alkyl groups from C 1 to C 3 , in particular carboxymethyl cellulose) or their mixed ethers such as carboxymethyl hydroxyethyl cellulose.
• the metal cations are generally used in the form of their salts with mineral acid anions or as acetates to prepare the complex-type reaction products; the divalent, trivalent or tetravalent, in particular the divalent, are preferred.
• the cations are in particular V 5+ , Bi 3+ , Al 3+ , Fe 3 + , Zr 4+ , Sn 4+ , Ca 2+ , Ba 2+ , Sr 2+ , Ti 3+ , Co 2+ , Fe 2+ , Mn 2+ , Ni 2+ , Cu 2+ , Zn 2+ or Mg 2+ ions.
• the metal cation is generally present as an octahedral complex both in aqueous solution and in the solid state, preferably two of the six coordination sites being occupied by the functional groups of the polymer and the four remaining coordination sites using anions of the salt used, Hydroxyl ions, amine ligands and predominantly water or completely filled with water.
• these products are dependent. it from the metal cation in more or less acidic Media soluble and are precipitated quantitatively when neutralizing the acidic solution with alkali hydroxide or ammonia; they are insoluble in neutral or alkaline aqueous and in the usual organic solvents.
• the treatment of these substrates with the solutions of the complex reaction products is expediently carried out by dipping formats or by passing the substrate tape through a bath of these solutions. Temperatures from 20 ° to 95 ° C., preferably from 25 ° to 60 ° C. and residence times from 2 seconds to 10 minutes, preferably from 10 seconds to 3 minutes, have proven to be the most favorable for practical use. An increase in the bath temperature favors the chemisorption of the polymer-metal complexes on the substrate. This makes it possible, especially in the case of continuous strip treatment, significantly reduce the dwell times.
• the immersion treatment is then expediently followed by a rinsing step with water, primarily with tap water.
• This rinsing process can serve on the one hand to remove excess treatment solution from the carrier, on the other hand the acidic treatment solution on the carrier is so strongly shifted towards the neutral point by dilution with water that the dissolved complexes can precipitate in the pores of the substrate and thus on the substrate Carriers are firmly fixed.
• the substrate treated in this way is then expediently dried at temperatures of 110 ° to 130 ° C.
• the treatment of the aluminum substrate can also be carried out as a two-step process.
• the substrate is immersed, for example, in a 0.2 to 10%, preferably 0.5 to 5%, aqueous solution of the starting polymer.
• the substrate can then be transferred without prior rinsing or drying into a second bath which contains a 0.1% to saturated, preferably 0.5 to 10% aqueous salt solution with the polyvalent metal ions listed above.
• the rinsing and drying is carried out as in the one-step process.
• the complex reaction products described above are formed on the substrate during the treatment. With this process variant, complex-type reaction products which are difficult to dissolve in strongly acidic media can be applied to the substrate.
• the support materials according to the invention thus produced can then be coated with various light-sensitive layers for the production of offset printing plates.
• the process parameters in the roughening stage are in the following ranges: the temperature of the electrolyte between 20 and 60 ° C, the active substance (acid, salt) concentration between 5 and 100 g / l, the current density between 15 and 130 A / dm 2 , the residence time between 10 and 100 sec and the electrolyte flow rate on the surface of the workpiece to be treated between 5 and 100 cm / sec; AC is usually used as the type of current, but modified types of current such as AC with different amplitudes of the current strength are also possible for the anode and cathode currents.
• the average roughness depth R z of the roughened surface is in the range from about 1 to 15 ⁇ m, in particular in the range from 4 to 8 ⁇ m.
• Negative-working condensation products from aromatic diazonium salts and compounds with active carbonyl groups preferably condensation products from diphenylamine diazonium salts and formaldehyde, which are described, for example, in DE-PS 596 731, 1 138 399, 1 138 400, 1 138 401, 1 142 871, 1 154 123 U.S. Patents 2,679,498 and 3,050,502 and G3 Patent 712,606.
• Negative mixed condensation products of aromatic diazonium compounds for example according to DE-OS 20 24 244, which each have at least one unit of the general types A (-D) n and B connected by a double-bonded intermediate member derived from a condensable carbonyl compound.
• A is the remainder of a compound containing at least two aromatic carbocyclic and / or heterocyclic nuclei, which is capable of condensing with an active carbonyl compound in an acidic medium at at least one position.
• D is a diazonium salt group attached to an aromatic carbon atom of A; n is an integer from 1 to 10; and B is the remainder of a compound free of diazonium groups and capable of condensing with an active carbonyl compound in an acidic medium at at least one position on the molecule.
• Positive-working layers according to DE-OS 26 10 842 which contains a compound which splits off acid when irradiated, a compound which has at least one COC group which can be split off by acid (e.g. an orthocarboxylic acid ester group or a carboxylic acid amide acetal group) and optionally contain a binder.
• acid e.g. an orthocarboxylic acid ester group or a carboxylic acid amide acetal group
• optionally contain a binder e.g. an orthocarboxylic acid ester group or a carboxylic acid amide acetal group
• the monomers used here are, for example, acrylic and methacrylic acid esters or reaction products of diisocyanates with partial esters of polyhydric alcohols, as described, for example, in US Pat. Nos. 2,760,863 and 3,060,023 and DE-OSes 20 64 079 and 23 61 041.
• photoinitiators are u. a. Benzoin, benzoin ethers, multinuclear quinones, acridine derivatives, phenazine derivatives, quinoxaline derivatives, quinazoline derivatives or synergistic mixtures of different ketones.
• soluble organic polymers can be used as binders, e.g. B. polyamides, polyesters, alkyd resins, polyvinyl alcohol, polyvinyl pyrrolidone, polyethylene oxide, gelatin or cellulose ether.
• Negative working layers according to DE-OS 30 36 077 which contain a diazonium salt polycondensation product or an organic azido compound as a photosensitive compound and a high molecular weight polymer with pendant alkenylsulfonyl or cycloalkenylsulfonylurethane groups as a binder.
• photoconductive layers such as z. B. in DE-PSen 11 17 391, 15 22 497, 15 72 312, 23 22 046 and 23 22 047 are described, to the invention manufactured carrier materials are applied, which results in highly light-sensitive, electrophotographic printing plates.
• the coated offset printing plates obtained from the carrier materials according to the invention are converted into the desired printing form in a known manner by imagewise exposure or irradiation and washing out of the non-image areas with a developer, preferably an aqueous developer solution.
• a developer preferably an aqueous developer solution.
• the base support materials were treated according to the invention with the complex-type Umsetzun g sproduk- th, to such plates where the same base material with the corresponding polymer was treated without conducted reaction with metal cations, through a considerably improved hydrophilicity of the non-image areas and by increased practical sensitivity to light (better layer adhesion).
• 0.2 mol, based on a vinyl methyl ether maleic anhydride unit, of the copolymer of vinyl methyl ether and maleic anhydride are dissolved in 600 ml of water at 85 ° to 100 ° C.
• the anhydride groups are hydrolyzed to the free acids.
• 0.2 mol of Co (NO 3 ) 2 dissolved in 200 ml of water is then slowly added dropwise to this solution; after the addition has ended, the mixture is stirred for a further hour. After the reaction solution has cooled to room temperature, it is neutralized by slowly adding dilute aqueous NaOH solution, during which the cobalt complex precipitates quantitatively as a viscous, rubbery pink-colored precipitate.
• Example 1 To prepare further polymer-metal complexes, the copolymer used in Example 1 is dissolved in dilute aqueous NH solution, in the course of which the maleic anhydride functions are hydrolyzed to amide or half-amide groups. The further reaction with the metal cation is carried out according to Example 1.
• a bright rolled aluminum strip with a thickness of 0.3 mm is degreased with an aqueous alkaline 2% pickling solution at an elevated temperature of around 50 ° to 70 ° C.
• the electrochemical roughening of the aluminum surface takes place 3 containing electrolyte with alternating current and in an ENT, it is a surface roughness with an R z value of 6 / .mu.m.
• the subsequent anodic oxidation is carried out according to the process described in DE-OS 28 11 396 in an electrolyte containing sulfuric acid, the oxide weight is 3.0 g / m 2.
• the aluminum strip prepared in this way is then passed through a bath heated to 60 ° C. from a 0.5% solution (in 2% H 3 PO 4 ) of the polymer-metal complex from the copolymer of vinyl methyl ether and maleic anhydride and Al 3+ -
• the dwell time in the bath is 20 seconds.
• the excess solution is removed with tap water in a rinsing step and the strip is dried with hot air at temperatures between 100 ° and 130 ° C.
• the printing plate produced in this way can be developed quickly and free of fog.
• the non-image areas are characterized by a very good ink-repelling effect.
• the contact angle measurement compared to a drop of water gave a value of 18 ° for the stripped material, the print run was 200,000.
• the printing forms received are free of copying and printing technology.
• the non-image areas have a very good ink-repellent effect, which manifests itself in the fast free running of the printing form in the printing press.
• the print run is 120,000.
• An electrochemically roughened and anodized aluminum sheet according to Example 4 is immersed for 30 seconds at room temperature in one of the phosphoric acid polymer-metal complex solutions (0.5%) listed below, dried and a sample with the light-sensitive layer from Example 4 and a sample with the photosensitive
• the printing plates produced in this way are distinguished by the same advantages as indicated in Example 13.
• the printing form thus produced is distinguished by a significantly improved ink-repelling effect of the non-image areas.

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• Printing Plates And Materials Therefor (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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• 1981
  • 1981-07-06 DE DE19813126626 patent/DE3126626A1/de not_active Withdrawn
• 1982
  • 1982-06-22 CA CA000405691A patent/CA1184448A/fr not_active Expired
  • 1982-06-23 US US06/391,154 patent/US4427766A/en not_active Expired - Lifetime
  • 1982-06-28 DE DE8282105717T patent/DE3274221D1/de not_active Expired
  • 1982-06-28 EP EP82105717A patent/EP0069319B1/fr not_active Expired
  • 1982-07-05 BR BR8203903A patent/BR8203903A/pt not_active IP Right Cessation
  • 1982-07-06 JP JP57116333A patent/JPS5818291A/ja active Granted

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