Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/50—Recording sheets characterised by the coating used to improve ink, dye or pigment receptivity, e.g. for ink-jet or thermal dye transfer recording
  • B41M5/502—Recording sheets characterised by the coating used to improve ink, dye or pigment receptivity, e.g. for ink-jet or thermal dye transfer recording characterised by structural details, e.g. multilayer materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/50—Recording sheets characterised by the coating used to improve ink, dye or pigment receptivity, e.g. for ink-jet or thermal dye transfer recording
  • B41M5/52—Macromolecular coatings
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H19/00—Coated paper; Coating material
  • D21H19/80—Paper comprising more than one coating
  • D21H19/84—Paper comprising more than one coating on both sides of the substrate
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
  • D21H27/06—Vegetable or imitation parchment; Glassine paper
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
  • G03G7/0006—Cover layers for image-receiving members; Strippable coversheets
  • G03G7/002—Organic components thereof
  • G03G7/0026—Organic components thereof being macromolecular
  • G03G7/0033—Natural products or derivatives thereof, e.g. cellulose, proteins
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G7/00—Selection of materials for use in image-receiving members, i.e. for reversal by physical contact; Manufacture thereof
  • G03G7/0006—Cover layers for image-receiving members; Strippable coversheets
  • G03G7/002—Organic components thereof
  • G03G7/0026—Organic components thereof being macromolecular
  • G03G7/004—Organic components thereof being macromolecular obtained by reactions only involving carbon-to-carbon unsaturated bonds
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M2205/00—Printing methods or features related to printing methods; Location or type of the layers
  • B41M2205/34—Both sides of a layer or material are treated, e.g. coated
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/50—Recording sheets characterised by the coating used to improve ink, dye or pigment receptivity, e.g. for ink-jet or thermal dye transfer recording
  • B41M5/502—Recording sheets characterised by the coating used to improve ink, dye or pigment receptivity, e.g. for ink-jet or thermal dye transfer recording characterised by structural details, e.g. multilayer materials
  • B41M5/508—Supports
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41M—PRINTING, DUPLICATING, MARKING, OR COPYING PROCESSES; COLOUR PRINTING
  • B41M5/00—Duplicating or marking methods; Sheet materials for use therein
  • B41M5/50—Recording sheets characterised by the coating used to improve ink, dye or pigment receptivity, e.g. for ink-jet or thermal dye transfer recording
  • B41M5/52—Macromolecular coatings
  • B41M5/5254—Macromolecular coatings characterised by the use of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds, e.g. vinyl polymers

Definitions

• the present invention relates to a transparent paper suitable for digital printing and to a method for producing the same.
• Transparent paper is used today mainly as a print carrier for prints in the area of highest quality and added value or as a technical drawing paper in the engineering and architecture sector. But also a use as high quality packaging material is known in the art.
• digital printing does not require a fixed artwork so that each sheet can be printed differently (so-called non-impact printing).
• indigo process what is commonly used in the art for printing on transparent paper is a so-called indigo process, which prints transparent paper by "melting" electrically charged, colored toner particles which, as liquid toner (electro ink) indirectly via blanket to the paper surface, similar to offset printing, be applied.
• a problem with the Indigo process for printing on transparent paper results from the very dense paper surface of the transparent paper, which causes the molten particles to adhere to the closed surface of the transparent paper not tight enough.
• This problem is usually solved by the application of a suitable surface coating, such as an ethylene-acrylic acid copolymer layer, before printing on the transparent paper on the printed side of the transparent paper, the coating solution firmly bonds to the surface of the transparent paper and at the same time a good Has affinity for the color particles to be printed.
• the application of the surface layer to the transparent paper is usually carried out (before printing) in the course of the production of the transparent paper in a subsequent step by means of a coating method in which the surface coating agent is applied to the printed side of the transparent paper using an organic solvent.
• this coating method using an organic solvent is disadvantageous in that the organic solvent is expensive, a 100% removal of the solvent on the surface-coated tracing paper is not possible, and the removed organic solvent must be disposed of consuming in a post-combustion.
• a coating of transparent paper with aqueous coating solutions or suspensions by means of a coating process on the print side of the transparent paper fails because the tracing paper due to its extremely high refining (leads to a high transverse strain and contraction and thus to a much lower dimensional stability of the transparent paper in Compared to other papers) reacts with water addition with dimensional changes ("waves" or "curling"). As a result, the surface coating layer applied by means of a coating process is damaged by contact with the web-guiding rollers in the paper machine and thus becomes uneven and unusable for printing.
• the printing of a surface layer coated transparent paper by means of an indigo printer also encounters the difficulty that the transparent paper fed to the indigo printer as a sheet material due to its high density and transparency of the feed rollers, which have the task of the paper perpendicular to the printing press to lead, not cleanly guided by the Indigo printer, but slipped and thus printed in the wrong way and / or wrinkled output from the printer.
• the first object of the present invention is therefore to provide a suitable for digital printing, for example by means of the indigo process transparent paper, which avoids the disadvantages described above.
• Another object of the present invention is to provide a method for coating transparent paper with an aqueous coating solution or suspension by means of a coating method, which avoids the disadvantages described above.
• the present invention furthermore relates to a process for producing a transparent paper according to the invention as claimed in patent claim 8 or 9 and to a process for coating a transparent paper with an aqueous coating solution or suspension by means of a coating process according to patent claim 10.
• the present invention furthermore relates to the use of a coated transparent paper produced by a process according to the invention for printing by means of a digital printer according to claim 15.
• the transparent paper used according to the invention is a transparent paper with a high freeness.
• the freeness, measured in ° Schopper Riegler (° SR), in the transparent paper used according to the invention is usually more than 60, preferably more than 80, in particular more than 90 ° Schopper Riegler.
• the transparent paper used according to the invention differs for example from parchment paper, glassine paper and / or parchment substitute paper.
• the degree of milling of these paper products is much lower (usually at 30-40 ° SR).
• Transparent paper thus has an unmistakable appearance. It is more transparent than parchment paper.
• the transparent paper to be used according to the invention usually consists of cellulose fibers which are obtained, for example, from rags or hardwood.
• the transparent paper consists of a long-fiber pulp, which is digested in the sulfate process.
• different mixtures of different cellulose fibers can also be used.
• the basis weight (paper weight) of the transparent paper according to the invention (the so-called grammage) is usually 40 to 250 g / m 2 , preferably 60 to 200 g / m 2 , in particular 100 to 150 g / m 2 .
• the transparent paper used according to the invention obtains its transparent character by strong grinding of the cellulose fibers. This creates numerous hydrogen bonds in the paper structure, which produce a very firm and hard structure of the final product.
• the transparent paper according to the invention is characterized in that it has on one surface a coating layer which has been formed by applying an aqueous solution or suspension to the side of a transparent paper to be printed.
• the coating of transparent paper with an aqueous solution or suspension is carried out according to the invention usually by timely or simultaneously with the application of an aqueous coating solution to the print side of a transparent paper, the non-printing back of the transparent paper with an aqueous solution or suspension, preferably Water or the coating solution, is moistened.
• an aqueous coating solution or suspension takes place according to the invention via a single-sided applicator, for example via a roller and / or doctor blade, for example a "reverse gravure coating", or by means of a roller via the size press.
• a single-sided applicator for example via a roller and / or doctor blade, for example a "reverse gravure coating", or by means of a roller via the size press.
• the application also by using one of the DE-OS 43 29 218 known suction roll over which the paper web is guided.
• the application of the aqueous solution or suspension to the backside of the transparent paper takes place via a roller and / or doctor blade.
• the application of the aqueous solution to the back of the transparent paper via a via a scrubcount before application of the aqueous coating solution to the printed side of the transparent paper.
• the amount of water to be applied to the back of the transparent paper for moistening this side is about 1 to 10 g / m 2 , preferably 3 to 5 g / m 2 of the transparent paper.
• the coating amount of the aqueous coating solution is in a range of 0.03 to 1.0 g / m 2 of solid content on a surface of the transparent paper.
• the aqueous coating solution comprises an ethylene-acrylic acid copolymer, since this copolymer results in a coating on the tracing paper, with which the advantageous properties of the digital offset printing can be well used.
• the ethylene-acrylic acid copolymer to be used for example, in the DE 101 32 884 A1 described used.
• the aqueous solution contains the ethylene-acrylic acid copolymer in a concentration of 1 to 20% by weight, preferably 5 to 10% by weight, based on the weight of the coating solution.
• the coating solution may further comprise other conventional auxiliaries, such as binders.
• the excess of aqueous coating solution is usually squeezed off by means of press rolls, after which the transparent paper is passed through a drying channel.
• the subject matter of a further embodiment of the present invention is a process for coating transparent paper with an aqueous solution or suspension, wherein the process is characterized in that upstream or at the same time as the application of an aqueous coating solution to the print side of a transparent paper not printing back of the transparent paper with an aqueous solution or suspension, preferably water or the coating solution is moistened.
• the transparent paper is characterized in that it has at least one strip of increased grip and opacity in at least one edge region of the transparent paper on at least one of the two surfaces, preferably on a surface thereof.
• the tracing paper used may be any tracing paper according to the above, or specifically one according to claim 1, having on one side a coating layer according to the above.
• the grip or surface roughness of the strip to be applied is defined according to the invention by measuring the slip angle (DIN 53119-2). While the transparent paper without strips usually has a slip angle of 5 to 12 °, preferably 9 to 11 °, the applied strip usually has a slip angle of 20 to 30 °, preferably 23 to 26 °.
• the opacity (DIN 53146) of the transparent paper according to the invention is usually 30 to 45%, preferably 36 to 40%, that of the strip to be applied is usually 80 to 90%, preferably 85 to 88%.
• the increased-grip tab may be a strip of a width of, for example, 5 to 20 mm, preferably 7 to 15 mm, in particular 8 to 12 mm, extending along one side of the transparent paper and extending inwardly from the edge of a transparent paper.
• the transparent paper according to the invention comprises in a preferred embodiment at least one such strip, preferably two strips extending inwardly from the opposite edges of the transparent paper.
• the strips of increased grip and opacity applied in at least one edge region of the transparent paper are a paper strip or a printed strip with a thickness of usually 10 to 30 ⁇ m, preferably 15 to 25 ⁇ m.
• the grip of the invention applied strip corresponds to a slip angle of usually 20 to 30 °, preferably 23 to 26 °.
• a paper strip of this surface grip or roughness can in one embodiment be glued or printed onto the transparent paper after its production on at least one edge surface in order to produce a transparent paper according to the invention.
• the transparent paper in the production process in the paper machine on a surface, preferably on the surface to be printed, with a strip or with an area, for example, the entire surface of the transparent paper on this side, increased grip be equipped by the Transparent paper, for example, in the size press with an additive, for example, silica powder having a particle size of usually 30 to 70 nm, preferably 40 to 60 nm, at least in an edge region of the transparent paper is added to form a strip of increased grip in at least this edge region of the transparent paper.
• an additive for example, silica powder having a particle size of usually 30 to 70 nm, preferably 40 to 60 nm
• this grip of this at least one strip in at least one edge region of the transparent paper it is ensured that the insertion roller (s) of the digital printer, for example an indigo printer, first capture this above-mentioned strip of transparent paper and thus the grippier paper surface, so that a perfect transport of the transparent paper according to the invention is achieved by the printer.
• the digital printer for example an indigo printer
• a translucent paper of pine sulfate cellulose having a basis weight of 112 g / m 2 and having a freeness of 92 ° SR is used.
• the coating agent used is an ethylene-acrylic acid copolymer from Michelman ("Digiprime 1500 LA.E).
• Example 1 on the tracing paper on both surfaces, an aqueous coating solution containing an ethylene-acrylic acid copolymer in a concentration of 8 wt .-%, applied in the form of uniform layers with a 1.0 g / m 2 solids content on the two surfaces of the transparent paper.
• Example 2 on a surface of a above-mentioned pine sulfate cellulose transparent paper having a basis weight of 112 g / m 2 and having a freeness of 92 ° SR, an aqueous coating solution containing an ethylene-acrylic acid copolymer in a concentration of 8 wt .-%, applied in the form of a uniform layer with a 1.0 g / m 2 solids content, while at the same time the back of the transparent paper is moistened with water.
• Example 3 the transparent paper coated on one or two sides with ethylene-acrylic acid copolymer is printed in an edge area with a white strip having a width of 8 mm, an opacity of 62.52% (according to DIN 53146) and a slip angle of 10 °, while the transparent paper without stripes has an opacity of 51.19%. It turns out that in all cases a transparent paper is obtained, which has a better grip and opacity.
• the transparent papers according to the invention are preferably suitable for digital printing.

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• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• General Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Paper (AREA)
• Laminated Bodies (AREA)

Applications Claiming Priority (1)

Publications (2)

Family

ID=42664630

Family Applications (1)

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Cited By (1)

Citations (2)

Family Cites Families (8)

• 2009
  • 2009-06-03 DE DE200910023762 patent/DE102009023762A1/de not_active Withdrawn
• 2010
  • 2010-05-25 EP EP10163741A patent/EP2258558A3/fr not_active Withdrawn

Patent Citations (2)

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