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
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/31504—Composite [nonstructural laminate]
  • Y10T428/31678—Of metal
  • Y10T428/31692—Next to addition polymer from unsaturated monomers

Definitions

• the invention relates to a mechanical and / or electrochemical roughened and optionally anodized Carrier material made of aluminum or its alloys with a hydrophilic layer of at least a polymer with basic and acid groups and a radiation-sensitive recording material with a Carrier and a radiation-sensitive layer from which Offset printing plates can be produced.
• Carrier materials for offset printing plates are made with a photosensitive layer (copying layer) provided with whose help is a printing image on photomechanical Ways is generated. After making the print In the picture, the layer carrier carries the printing areas of the picture and at the same time forms in the non-image areas (non-image areas) the hydrophilic background for the lithographic printing process.
• the carrier material is usually additionally hydrophilized, because otherwise it won't take in enough water.
• the hydrophilizing agent must be sensitive to the particular light Layer to be matched to unwanted reactions to avoid and not to affect liability.
• the known hydrophilization methods are dependent from the photosensitive layer, the developer solutions or correction means - with more or less large ones Disadvantages. So after treatment with alkali silicates, to developability and hydrophilicity cause deterioration of photosensitive Shifts accepted after a long storage period. At the treatment of substrates with water-soluble Polymers have good solubility - especially in aqueous-alkaline developers, such as those used predominantly for Developing positive working layers used become - for the significant weakening of the hydrophilizing Effect.
• the sulfonic acid groups contain, has a negative effect that free anionic Acid functions with the diazo cations of negative interacting light-sensitive layers can occur so that after developing on the Non-image areas through a clear color fog retained diazo compounds is recognizable.
• Polymers Acrylic acid derivatives are disadvantageous because they are in the Application form in which you can prevent color fog, i.e. in a solution of 0.1 to 10 g / l, very viscous are and a surplus only with great effort from remove the surface of the carrier.
• Especially highly sensitive to light are susceptible to color fog Layers used for imaging with lasers are (EP-A 0 364 735) and a polymer Binder, a radical polymerizable compound with at least one polymerizable group and one photoreducible dye, one that can be cleaved by radiation Trihalomethyl compound and a metallocene compound included as photoinitiators. It will therefore particularly high demands on the hydrophilic carrier material so that none at the non-image areas Components of the layer remain.
• the carrier material is included a homopolymer of acrylamidoisobutylenephosphonic acid or a copolymer of acrylamidoisobutylenephosphonic acid and acrylamide or with a salt of this homo- or Copolymers with an at least divalent metal cation coated.
• the coating has the advantage that the finished printing plates at the non-image areas a good one Show hydrophilicity and a reduced color haze exhibit.
• EP-A 0 490 231 describes the treatment of printing plate supports with polyethyleneimines which contain structural elements of the type - (CH 2 -CH 2 -N (X) -) n - or with polyvinylamines, the structural elements of the type - (CH 2 -CH (NY 1 Y 2 ) -) n - contain, where X, Y 1 and Y 2 are optionally C-substituted sulfomethyl groups or phosphonomethyl groups. But even with this method, optimal results are not yet achieved.
• the task is solved by a mechanical and / or electrochemically roughened and optionally anodic oxidized carrier material made of aluminum or its alloys with a hydrophilic layer of at least a polymer with basic and acidic groups, thereby characterized in that another hydrophilic on the layer Layer follows that has at least one connection contains at least one phosphono group.
• the basic groups in the polymer of the first hydrophilic Layer are preferably primary, secondary or tertiary Amino groups, the acidic groups are preferred Carboxy, phosphono or sulfo groups.
• the secondary and tertiary amino groups can also be a constituent the main polymer chain. Particularly preferred for this
• the first hydrophilic layer is that in EP-A 0 490 231 described sulfomethylated or phosphonomethylated Polyethyleneimines and polyvinylamines. These polymers can also units from other monomers included, e.g. Units of substituted amino acrylates, Vinyl pyrrolidones or vinyl imidazoles.
• the compounds used for the further hydrophilic layer with at least one phosphono group are against it clearly acidic. They generally have in aqueous solution a pH of less than 4, preferably 1 to 3. These compounds are also preferably polymeric, wherein the polyvinylphosphonic acid described in US-A 4,153,461 is particularly suitable.
• the sequence of the hydrophilizing layers is surprisingly crucial for the quality of the product Meaning. There is no proven one for this Explanation, but there are hypothetical ideas. It is believed that the layer consists of at least one polymer with acidic and basic groups adsorption sites creates, which then connects with at least attaches to a phosphono group to a greater extent than it would be without this activation. This is in so far as it is plausible, as it deals with different surface-sensitive Methods such as energy dispersive X-ray (EDX), Auger electron spectroscopy, electron spectroscopy for chemical analysis (ESCA) and secondary ion mass spectroscopy (SIMS), shows that only this Sequence of layers a particularly large amount of Active ingredients on the surface of the carrier.
• the Hydrophilic layers can be continuous or discontinuous be.
• part of the present invention is a Process for the production of the carrier materials.
• the two Hydrophilizing layers can be sprayed on the corresponding solutions or by immersing them in them Solutions are applied.
• the concentration of Can hydrophilize compounds in these solutions fluctuate within wide limits. However, there have been solutions with a concentration of 0.1 to 50 g / l, preferably from 0.3 to 5 g / l, is particularly advantageous proven.
• the coating can be at temperatures from 20 to 95 ° C happen, but temperatures are from 30 to 65 ° C prefers.
• the material to be coated is generally sprayed or immersed for 1 s to 5 min each. It is disadvantageous if the treatment time is shorter than 1 s, but not if it is more than 5 min.
• the second hydrophilic layer is generally in the applied in the same way as the first.
• the used for this Spray or immersion solutions have about that same concentration.
• the coated one Appropriately at temperatures of 100 to Dried 130 ° C.
• the determination of the weight of the applied hydrophilic coating is problematic since even small amounts of the product show a clear hydrophilizing effect.
• the hydrophilizing agents also adhere relatively strongly to the surface of the carrier material.
• the amount applied is in any case less than 0.5 mg / dm 2 , in particular less than 0.25 mg / dm 2 .
• the minimum amount is about 0.02 mg / dm 2 .
• the quantities given apply individually to each of the two levels.
• the carrier materials according to the invention can then coated with various light-sensitive mixtures will. Basically all mixtures are suitable result in the layers that after imagewise exposure, subsequent developing and / or fixing positive or negative picture. At the non-image areas retains the material suitable as a pressure plate its excellent hydrophilicity and leaves practically none Recognize color veil more.
• the present invention therefore also relates to Recording material with an aluminum or its alloys and a radiation sensitive Layer, which is characterized in that the carrier is hydrophilized as described above.
• 0.3 mm thick bright rolled aluminum (DIN material no. 3.0255) was degreased with a 2% aqueous NaOH pickling solution at a temperature of 50 to 70 ° C.
• the surface was then electrochemically roughened using alternating current in an electrolyte containing HNO 3 .
• the R z value of the surface roughness was then 6 ⁇ m.
• the subsequent anodic oxidation was carried out in an electrolyte containing sulfuric acid.
• the oxide layer weight was approximately 3.0 g / m 2 .
• 0.3 mm thick bright rolled aluminum (DIN material no. 3.0515) was degreased with a 2% aqueous NaOH pickling solution at a temperature of 50 to 70 ° C.
• the surface was electrochemically roughened using alternating current in an electrolyte containing hydrochloric acid.
• the R z value of the surface roughness was then 6 ⁇ m.
• the subsequent anodic oxidation was carried out in an electrolyte containing sulfuric acid.
• the oxide layer weight was approximately 2.0 g / m 2 .
• 0.2 mm thick bright rolled aluminum (DIN material no. 3.0255) was degreased with a 2% aqueous NaOH pickling solution at a temperature of 50 to 70 ° C and then mechanically roughened with cutting grains (e.g. quartz powder or aluminum oxide). The R z value of the surface roughness was then 4 ⁇ m. The subsequent anodic oxidation was carried out in an electrolyte containing phosphoric acid. The oxide layer weight was about 0.9 g / m 2 .
• This carrier corresponds to that of type 2, with the only difference that it has been anodized up to an oxide layer weight of 1.5 g / m 2 .
• the hydrophilizations A * to D * according to Table 1 were used for the comparative experiments, while the support material according to the invention was hydrophilized according to E.
• the plates were placed in a vacuum contact copier contacted by evacuation with a test assembly, with a 5kW metal halide-doped mercury vapor lamp exposed at a distance of 110 cm so that after development an open level 4 resulted in the UGRA offset test wedge, which corresponds to a high exposure for film edge removal.
• a developing device VA86 from Hoechst AG
• developer type 2 O'-bis-carboxymethyl-polyethylene glycol- 1000 of 0.6 wt .-%
• the occurrence of residual layer haze is investigated after a developer load of 4 m 2 per liter of developer.
• hydrophilization E of the invention has been found Carrier as more advantageous.
• the plate was then dried with a layer of polyvinyl alcohol covered, exposed and developed.
• Examples 6 to 34 (Table 6/7) are intended to be the superiority the carrier of the invention on the according to the table 1, A to D, hydrophilized carrier of the comparative examples V1 to V52 are shown.
• the recording materials, made according to the in the tables conditions were examined as follows:
• the non-image area of a printing plate was marked with a commercial correction agents treated. After that measured the brightness, once in the corrected and once in the uncorrected area. here too the difference dL * was formed. It is essential different from 0, i.e. in the range of 0.5 to 1, that has Corrective agent either layer remnants from the Can peel off the surface or even the surface the non-image area itself attacked and damaged.
• Carriers of types 1 and 2 were anodized and treated with an aqueous solution of a polyvinylphosphonic acid in an immersion bath for 5 seconds.
• the conditions are given in Table 3.
• the plates were coated with the solution given in Example 1, exposed and developed with a developer of types 1 or 2 in the above-mentioned developing device VA86. No.
• Table 3 shows that those not produced according to the invention Printing plates in the non-image areas one have sufficiently good hydrophilicity (as far as it determines was), but either have a clear color haze or an attack by the corrective suffer from discoloration in the non-image areas leads, or both appearances. Although two different ones Carrier types were used and two different developers used is not one of those listed in the table Combinations capable of all properties to show good results.
• the recording materials according to Table 4 were produced with a type 2 support and treated with a phosphonomethylated polyimine according to EP-A 0 490 231.
• This polymer had a molecular weight M w of about 80,000.
• No. temperature concentration brightness Color veil Correction contrast Hydrophilicity ° C g / l L * dL * 1 dL * 2 s V13 22 2.0 78.93 2.08 1.75 5 V14 30th 2.0 78.94 0.96 1.28 15 V15 40 2.0 78.95 0.86 1.13 5 V16 50 2.0 79.02 0.53 0.80 5 V17 60 2.0 79.00 0.41 0.76 5 V18 22 1.0 78.97 2.31 1.88 5 V19 30th 1.0 79.01 0.67 0.96 5 V20 40 1.0 78.44 0.57 1.08 5 V21 50 1.0 79.00 0.51 0.62 15 V22 60 1.0 78.96 0.25 0.57 15 V23 22 0.5 79.05 2.06 0.98 5 V24 30th 0.5 79
• Carriers of type 2 in Table 6 and of type 4 in Table 7 were first immersed in an aqueous solution of the phosphonomethylated polyimine and then - after a rinsing step - in an aqueous solution of polyvinylphosphonic acid for 5 s. Diving times of up to a few minutes have the same effect. However, a minimum immersion time of 1 s per bath must be observed. No.

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• 1994
  • 1994-07-01 DE DE19944423140 patent/DE4423140A1/de not_active Withdrawn
• 1995
  • 1995-06-19 US US08/492,148 patent/US5637441A/en not_active Expired - Fee Related
  • 1995-06-21 ES ES95109599T patent/ES2113696T3/es not_active Expired - Lifetime
  • 1995-06-21 DE DE59501625T patent/DE59501625D1/de not_active Expired - Fee Related
  • 1995-06-21 EP EP19950109599 patent/EP0689941B1/de not_active Expired - Lifetime
  • 1995-07-03 BR BR9503065A patent/BR9503065A/pt not_active Application Discontinuation
  • 1995-07-03 JP JP7167485A patent/JPH0858264A/ja active Pending

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