Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41F—PRINTING MACHINES OR PRESSES
  • B41F27/00—Devices for attaching printing elements or formes to supports
  • B41F27/12—Devices for attaching printing elements or formes to supports for attaching flexible printing formes
  • B41F27/1293—Devices for filling up the cylinder gap; Devices for removing the filler
• • 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
  • B41N6/00—Mounting boards; Sleeves Make-ready devices, e.g. underlays, overlays; Attaching by chemical means, e.g. vulcanising
  • B41N6/02—Chemical means for fastening printing formes on mounting boards
• • 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
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S430/00—Radiation imagery chemistry: process, composition, or product thereof
  • Y10S430/1053—Imaging affecting physical property or radiation sensitive material, or producing nonplanar or printing surface - process, composition, or product: radiation sensitive composition or product or process of making binder containing
  • Y10S430/1055—Radiation sensitive composition or product or process of making
  • Y10S430/106—Binder containing
  • Y10S430/108—Polyolefin or halogen containing

Definitions

• the invention relates to a method for covering edges and / or filling openings or gaps that occur during application of photopolymerizable printing plates and Photopolymer printing forms for flexographic printing on one Printing cylinder are formed in which the edge covering or Gap filling material applied and by exposure to actinic radiation is cured.
• the photopolymerizable Printing plate exposed by an original the unexposed Areas are washed out with a solvent and if necessary there is a chemical aftertreatment and / or full-surface post-exposure. These treatment steps can if necessary also be carried out on the impression cylinder.
• Printing forms often composed of individual sections.
• the need for assembly can be be due to the motif to be printed or for reasons of Economy or to get larger plate formats.
• the printing plate or printing form is around the Printing cylinders laid around so that their ends meet. The fixation then takes place by means of gluing double sided tapes. Are made up of individual parts Printing forms are used, so the edges of the glued individual parts.
• gap filling materials often have too little Resistance to the ink solvents on and are the mechanical stresses caused by the printing process not grown. This causes cracks in the Gap filling material that can now take up printing ink again and thus leads to undesired printed images. That too is Applicability of the known gap filling materials often increases bad and cumbersome.
• the present invention was therefore based on the object To avoid disadvantages of the prior art and the Application of flexographic printing forms and plates occurring column flexible, reliable, quick and easy to close, the gap filling material being the same Color transfer should show like the printing form itself, so that Full areas can be printed more completely than before.
• the photopolymerizable materials according to the invention can therefore the gap between mounted on printing cylinders flexographic printing forms and the column between the Printing form edges and the printing cylinder surface flexible and be permanently closed. So the intrusion can of printing inks or their solvents prevented and that this causes detachment of the printing forms from Prevents printing cylinders during the printing process and the Synchronization properties can be improved. Likewise, Full areas printed more completely because of the gap filling material shows the same color transfer as the printing forms themselves.
• low molecular weight compounds in the photopolymerizable mixtures are the known mono- or polyunsaturated monomers such as Esters or amides of acrylic acid or methacrylic acid with mono- or polyfunctional alcohols, amines, amino alcohols or Hydroxyethers and esters used.
• the molecular weights these compounds are preferably ⁇ 800, particularly preferred 100 to 600.
• Mixtures of mono- and polyunsaturated compounds as described in DE-C1 37 44 243 and DE-A 36 30 474 are described.
• oligomeric compounds in the photopolymerizable mixtures generally known compounds such as, for example, acrylic ester-butadiene copolymers, methacrylic acid ester-butadiene copolymers, styrene-butadiene copolymers, 1,2- and 1,4-polybutadienes, acrylated polybutadienes, methacrylated polybutadienes, Polyisoprenes or derivatives of these oligomers can be used.
• Styrene-butadiene copolymers, (meth) acrylated polybutadienes and (meth) acrylic ester-butadiene copolymers are preferably used.
• the molecular weights (M n ) of the oligomeric compounds according to the invention are between 1000 and 10,000, preferably between 2000 and 5000.
• the photopolymerizable mixtures also contain one of the known photoinitiators or a Photoinitiator system, e.g. Methylbenzoin, benzoin acetate, Benzophenone, benzil dimethyl ketal, ethyl anthraquinone / 4,4'-bis (dimethylamino) benzophenone.
• a Photoinitiator system e.g. Methylbenzoin, benzoin acetate, Benzophenone, benzil dimethyl ketal, ethyl anthraquinone / 4,4'-bis (dimethylamino) benzophenone.
• the weight ratio of the low molecular weight compounds to the oligomeric compounds in the invention photopolymerizable mixtures is ⁇ 2: 1, preferably ⁇ 2.5: 1, particularly preferably 2.5: 1 to 4: 1, in particular 2.8: 1 to 3.5: 1.
• the photopolymerizable mixtures according to the invention also contain 0.5 - 5 wt .-% initiator. Up to 10% by weight other aids such as Fillers, binders, Dyes, antioxidants, antiozonants, thermal Polymerization inhibitors and plasticizers can be contained in the mixtures. In particular up to 10% by weight, preferably 1-8% by weight, particularly preferably 1-6% by weight, binders can be added.
• Preferred Binders are those that are used with the binders Printing plates are compatible.
• thermoplastic elastomeric block copolymers In particular linear and / or radial polystyrene-polybutadiene-polystyrene or polystyrene-polyisoprene-polystyrene block copolymers and Styrene / butadiene copolymers are suitable. To be favoured Polystyrene-polybutadiene-polystyrene block copolymers are used. Solvents are for the applicability of the invention Mixtures are not necessary.
• the introduction of the gap filling materials into the closing column is carried out with the specialist familiar Methods, preferably by injecting using disposable syringes or injection pistols, as it is also in DE-B 36 00 774 and GB-B 2,160,882. Corresponding smooth Precision bevel cuts on the edge of the printing forms or -Plates are not necessary.
• Gap filling materials are made by exposure to actinic Radiation of any kind.
• Suitable radiation sources for this are, for example, mercury vapor lamps, incandescent lamps special phosphors that emit ultraviolet light, Argon light bulbs and photo lamps.
• the most suitable of these are the mercury vapor lamps, in particular Ultraviolet light lamps and UV fluorescent lamps.
• the gap filling material is hardened and the Printing forms are connected so that the filled gap has the same printing properties as the printing plate material and continuous printing can be done.
• a commercially available Cyrel® PLS flexographic printing plate from DuPont was exposed, developed as described in DE-B 36 00 774, and mounted on a printing cylinder using double-sided adhesive tape.
• the gap occurring at the abutting edges (1 - 3 mm) was sealed with UV-permeable adhesive tape and with a photopolymerizable mixture according to the invention consisting of 46% lauryl acrylate, 19% polyethoxylated 4-nonylphenol acrylate (4 mol ethylene oxide), 5.8% hexamethylene glycol diacrylate, 23.2% polybutadiene methacrylate ( M n 3000-4000), 4% of a polystyrene-polybutadiene-polystyrene block copolymer (Mw 130,000), 1.5% initiator and 0.5% inhibitor.
• the viscosity of the mixture was 360 cPs. After full-surface exposure with a commercially available Cyrel® printing plate exposure device, the gap filling material showed
• Printing tests were carried out with the printing cylinder thus produced 100 and 200 m / min performed.
• the gap filling material was stable against the inks and showed a good Color transfer that corresponded to that of the printing form.
• an above-mentioned printing plate was processed and the gap was coated with a photopolymerizable mixture according to the invention of 44% lauryl acrylate, 20% polyethoxylated 4-nonylphenol acrylate (4 mol ethylene oxide), 6.5% hexamethylene glycol diacrylate, 24% polybutadiene methacrylate (M n 3000 - 4000), 4% of a polystyrene-polyisoprene-polystyrene block copolymer (M w 130,000 to 150,000), 1.0% initiator and 0.5% inhibitor sealed.
• the viscosity of the mixture was 390 cPs.
• the gap filling material After full-surface exposure with a commercially available Cyrel® printing plate exposure device, the gap filling material showed a hardness of 67 Shore A and a rebound resilience of 34.8%.
• Printing tests were carried out with the printing cylinder thus produced 100 and 200 m / min performed.
• the gap filling material was stable against the inks and showed a good Color transfer that corresponded to that of the printing form.
• an above-mentioned. printing plate processed and the gap with a photopolymerizable Mixture of 92.5% polyethoxylated 4-nonylphenol acrylate (4th Mol ethylene oxide), 1.5% hexamethylene glycol diacrylate, 5% one Polystyrene-polybutadiene-polystyrene block copolymers (Mw 130 000) and 1.0% initiator closed.
• the viscosity of the The mixture was 230 cPs.
• the gap filling material showed a hardness of 42 Shore A and a rebound resilience of 18.0%. No usable impression cylinder was obtained because that Gap filling material stuck to the adhesive tape.
• an abovementioned printing plate was processed and the gap was coated with a photopolymerizable mixture of 27% lauryl acrylate, 15% hexamethylene glycol diacrylate, 38% polybutadiene methacrylate (M n 3000 - 4000), 19% of a 1.4 polybutadiene (melting temperature approx. - 50 ° C) and 1.0% initiator closed.
• the viscosity of the mixture was 749 cps.
• the gap filling material After full-surface exposure with a commercially available Cyrel® printing plate exposure device, the gap filling material showed a hardness of 80 Shore A and a rebound resilience of 31%. A usable impression cylinder was not obtained because the photopolymerizable gap filling material was inhomogeneous and the exposed material was too hard.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Photosensitive Polymer And Photoresist Processing (AREA)
• Printing Plates And Materials Therefor (AREA)
• Sealing Material Composition (AREA)
• Supply, Installation And Extraction Of Printed Sheets Or Plates (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=7816073

Family Applications (1)

Country Status (4)

Families Citing this family (5)

Family Cites Families (24)

• 1996
  • 1996-12-23 DE DE19654103A patent/DE19654103A1/de not_active Withdrawn
• 1997
  • 1997-12-01 US US08/982,104 patent/US5998098A/en not_active Expired - Fee Related
  • 1997-12-11 DE DE59704862T patent/DE59704862D1/de not_active Expired - Lifetime
  • 1997-12-11 EP EP97121811A patent/EP0850781B1/de not_active Expired - Lifetime
  • 1997-12-24 JP JP35541697A patent/JP4230552B2/ja not_active Expired - Fee Related

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