WO1994018609A1

WO1994018609A1 - Process, printing material and device for reproducing holographic fine structures and other diffraction grids on print products

Info

Publication number: WO1994018609A1
Application number: PCT/DE1993/000111
Authority: WO
Inventors: Johannes Matthiesen
Original assignee: Matthiesen, Gerda
Priority date: 1991-09-30
Filing date: 1993-02-10
Publication date: 1994-08-18
Also published as: CA2155850A1; CN1095167A; DE4132476A1

Abstract

The description relates to a process for the simultaneous replication and direct application of holograms and other diffraction grids on various printing materials (6), especially paper or cardboard. It is performed in the shaping process using a matrix bearing the hologram as a surface relief structure. One or more coats of lacquer (3, 7, 9) are applied to a printing material (6) with a substantially smooth surface and thus the surface of the printing material (6) is smoothed further. The hologram is simultaneously shaped into the surface of the coating applied to the printing material (6). The lacquer coating (3) can be hardened by radiation and the lacquer coats (3) are hardened from the matrix side through the u/v-tranparent matrix and through a matrix support (14) (a plate or cylinder) which is also u/v-transparent. The lacquer coat(s) (3, 7, 9) is/are essentially hardened before the printing material (6) is removed from the matrix and in contact with the matrix or the shaping cylinder.

Description

Procedure. Printing material and Eirr.chtunα r duplication of holographic fine structures and other diffraction gratings on printed products

The invention relates to a holographic multiplication process for molding holograms and other light-diffractive or light-refractive fine structures (diffraction gratings) according to the preamble of claim 1. to various printing substrates, a device for applying a hologram to a printing substrate and the production of associated printing matrices and egg nens substrate suitable for these processes

Holography is a recording and reproduction technique which enables objects to be represented spatially. Storage medium and information carrier are usually films and disks

A common hologram is either unique or can only be economically copied in relatively limited numbers, e.g. like a photo

It is known to thermoplas the structure of a surface relief hologram and then to transfer it to different substrates (carriers)

So far, the multiplication of surface reflective holograms and their integration into print products has involved three production stages

The holographic image is usually molded into a carrier material as a surface relief structure and only then, after further equipping with an adhesive or adhesion promoter, transferred to the printing material in a detailed process step

It is molded from dies, bands or rollers by means of pressure and temperature in thermoplastic plastic surface

REPLACEMENT LEAF Such a prehistoric pattern has so far been processed into two product variants after molding, namely so-called sealing holograms or self-adhesive holograms

Both product variants are pre-products that can only be applied to the printing material in an additional work step in further processing or packaging. Direct thermoplastic embossing in printing materials without subsequent transfer step is also possible, as described in DE-A 37 44 650 des Inventor is known

A process for producing holograms is usually carried out as follows

In the preliminary stage, the so-called mastenng, a laser transmission hologram is created from the original object as a three-dimensional image of the object by means of laser light. This master hologram, which has stored the entire surface information of the object in an interference pattern. however, it can only be viewed under laser light

A copy of the laser transmission hologram, the master, which can be viewed with normal directed whiteness is produced. This type of hologram is called a white light transmission hologram

Likewise, other diffraction gratings are produced holographically by means of laser light or mechanically by means of engraving, which give rise to decorative or technically / scientifically applicable light effects

In order to obtain a moldable surface relief structure for the embossing process, the duplication or the replication, this master hologram or diffraction grating is copied into a plate coated with photoresist or into other materials forming a surface relief

Depending on the partial intensity distribution during exposure, the applied photoresist, for example, is more or less strongly hardened in the negative process or more or less dissolved in the positive process. The subsequent development will result in a corresponding network or resolution Surface relief structure exposed The light is diffracted in an image-forming manner on this surface and on the later embossed surface structure

The light diffractive and refractive surface relief structures can also be generated mechanically, ie cut or engraved or engraved by means of a laser. The resolution or line width of mechanically generated diffraction ^¬ grid is dependent on the selected for their production technical process

A surface relief hologram has a fine structure of approx. 0.2 to 1 my height difference and a resolution of 800 to 1800 lines per millimeter

The surface of the photoresist is made electrically conductive in order to be able to electrogalvanically mold the subsequent stamp. This is done by chemical metallization using nickel or silver reduction processes. Vacuum coatings or sputtering can also be carried out

The so-called family is drawn from the photoresist in galvanic nickel sulfamate bath using a positive / negative method. The photoresist pulls the so-called production shim in nickel as pragmatts in several steps. The family generated here consists of great-grandmother, grandmother, div nuts and any number of daughters, the production shims (pragmatics)

The production matrices produced by the hologram are, depending on requirements, between 50 and 100 my and more thick and can be reproduced in the thermoplastic stamping process. For special purposes it is expedient to produce thicker stamping plates and stamps, endless belt loops or cylinders

Using certain pressures and temperatures, the surface structure of the pragmatics is thermally-plastically deformable surfaces or lacquer layers are stamped in. The material and motive matching of the 3 stamping parameters of pressure, temperature and speed is of crucial importance. The surface heating of the materials to be stamped must be checked very precisely. to search for a specific range between the softening point and the melting point of the material

Before embossing, the surface to be embossed can already be metallized. This enables in particular the optical control (quality control) of the embossing result during the embossing. The metallization also prevents the printing material from sticking to the matrix

Essentially two materials and systems have been used

A self-adhesive products

It was embossed in foils or in co-extruded foils or in thermoplastic coating systems, which are based on thermally dimensionally stable substrates (carriers), e.g. Polyester foils were applied. These systems were generally equipped with self-adhesive or laminated onto various carriers.

The typical layer structure of a conventional holographic or diffractive self-adhesive film consists essentially of

1 polyester substrate (carrier) 50 to 100 my thick,

2 optional adhesive agent (Pπmer)

3 lacquer layer, thermoplastic, as a hologram support, 0.9 to 2.5 my thick or approx. 1.2 - 3.5 g / qm, or alternatively instead of 1 + 2 + 3 only

4. PVC or vinyl film or other thermoplastically deformable films.

50 to 100 my and stronger; and then

5 Metallization approx. 300 angstroms strong, for a good optical density of 1.8 - 2

6 acrylic adhesives 4 - 10 g / qm

7 silicone protective paper e.g. 50 g / qm for labels (roll goods) or e.g. 90 g / qm for stickers (stay flat version) When A;. ..--, a self-sticking decorate ehologrammes is the hologram to ^¬ together with the Tragerfilm on a backing of glued this purpose, the usually provided 50 microns and greater Tragerfilm after embossing on the me ^¬ tallized compounds side with a self-adhesive coating and covered with a silicone protective paper which is peeled off before or during application

Heat seal fo

During embossing of holograms in Heißsiegelfohe eg, then transfer the paint layer which contains the embossed holographic fine structure in egg ^¬ nem additional production step by means of heat-activatable hot-seal adhesive on the pad

The typical layer structure of a conventional heat sealing film consists essentially of

1 polyester substrate (carrier). 12 to 25 my strong

2 separating layer 0.5 - 2 g / qm

3 possibly a clear or colored top coat layer 0.5 - 1.5 g / qm

4 one or more layers of lacquer or colored lacquer as the actual hologram support, 0.9 to 2.5 my thick, approx. 1.1 - 3.25 g / qm.

5 metallization approx. 300 angstroms for good optical density from 1.8 - 2

6 heat seal adhesives 0.7 - 2.5 g / qm

As a rule, the metallization takes place before the embossing, but can also take place subsequently

The structure-absorbing lacquer used is generally optically clear and thermoplastic deformable. Its softening point or the glass transition temperature is higher than the melting point of the heat-activatable heat-seal adhesive applied later to the metallization. This heat seal adhesive can therefore only be applied to the embossed metal side of the heat seal film after it has been embossed The holograms or diffraction gratings located in the varnish of the heat sealing ^sheet are now transferred to the printing material by means of certain contact pressures and temperatures

The heat seal adhesive and the separating layer are activated by the heat transferred with a heated pressure plate or roller

By exerting a certain pressure, the paint layer of the film is thereby connected to the substrate After a certain residence time, the Polyesterfohe of the new composite made abge ^¬ finally moved

Even if the thermoplastic stamping process itself can be described as relatively fast. e.g. between 2,500 and 25,000 cycles per hour, after which the additional app needed to decorate the product to be decorated, especially in the heat-sealing process, represents a time and calculation bottleneck

The sealing speed with a heat seal flat press is 800 to 2,200 cycles per hour. The sealing speed with a heat sealing cylinder machine is 1,500 to 3,500 cycles per hour

A clocked lifting or coding press can achieve up to 6,000 cycles (hologram applications) per hour in small formats

The sealing speed is limited by the fact that the material to be stamped requires a certain temperature and a certain dwell time on the printing material before perfect adhesion is achieved

In addition, there is the risk of bubbles forming due to outgassing of the printing material or the adhesive, which is particularly noticeable in flat presses

Disadvantages of this method are particularly in additional Ma ', al / cost for the Heißsiegelfohe itself, two ^¬ least in the carried out after finishing αem embossing with heat seal adhesive, and thirdly to the extent necessary for transmission of the hologram to sätzlichen ^¬ heat sealing process

The known methods described above are too expensive, especially when taking into account the high number of runs or production speeds common in today's communication technology and the need for a reasonable cost-benefit ratio

The invention has the object of providing a process for the direct loading ^¬ druckung a printing material, in particular paper. To specify cardboard and opaque films with holograms or other fine structures, which enables a high printing speed at low costs.

Furthermore, the invention is based on the object of specifying a printing material suitable for the purposes of the invention or its structure.

Furthermore, the invention is based on the object of specifying a device for taking an impression and for directly applying a hologram to a printing material.

Finally, the invention is based on the object of specifying methods and devices for producing suitable printing or impression matrices.

These objects are achieved by the invention specified in claims 1, 8 and 18. Advantageous developments of the invention are specified in subclaims.

The invention has the following advantages in particular.

1. the saving of the adhesive coating of the holograms that was previously necessary after embossing, 2 the saving of the application layer necessary after the adhesive coating, ie. the transfer of the finished embossed hologram to the printing material

The method according to the invention enables the direct printing of paper. Carton and other substrates without use of a Zwischenträ ^¬ gers and without execution of intermediate steps

The materials and further processing stages previously required for heat-sealing hoiograms or self-adhesive holograms can be dispensed with by the invention

The invention allows mass reproduction of holographic information or diffraction gratings that is appropriate for the media, at low cost and with significantly increased production speeds

The method according to the invention of UV-hardening molding of holograms and other diffraction gratings by means of radiation through a UV-permeable printing cylinder and through a UV-permeable matrix offers great qualitative, technical and economic advantages over known thermoplastic methods and especially over other radiation - hardening processes, such as the very process-intensive and hardware-consuming electron beam hardening

Especially when molding holographic fine structures and other diffraction gratings on largely UV-opaque substrates such as paper or cardboard or opaque foils, plastic papers and fabrics, the method according to the invention offers great advantages because the impression medium is now passed through the cylinder and the die by means of UV radiation in the Contact with the forme cylinder can be hardened

So far, it has only been possible with UV-opaque printing materials to work by means of thermoplastic impression or by means of the electron beam hardening penetrating through the paper to harden the impression medium from the printing material side or the substrate foamer According to the invention takes place in the molding and curing particular Rota ^¬ tion process by ultraviolet radiation from the die side through a UV transparent forth die and through a UV-transparent mold also through the cylinder wall by means of a cylinder disposed inside the UV radiation source

According to the invention, the impression and hardening can also be carried out in a single step process (step-and-repeat). In contrast to rotation, a flat die and a flat die-holder plate are used, which are also both UV-transparent,

The following product forms are for example by means of the inventive procedural ^¬ proceedings produced with the same basic construction machine

1 paper and cardboard and other largely UV undurchlassige Imprinted ^¬ materials or plastic papers, for example so-called PE-Papιere / Poiyester- papers

The inexpensive paper version is preferably processed into labels. Packaging and gift wrapping paper, cardboard and Ver ^¬. Decorative paper or wallpaper

2 Self-supporting plastic films, transparent or opaque, in thicknesses from 15 to 150 my and more. This product form can be partially self-adhesive or processed into laminates. Here, solid sub ^¬ strate may also find use tissue. The transparent product form will also be used without metallization as a transmission diffraction or diffraction grating for technical, scientific and optical purposes as well as for light and show effects

3 fo en multilayer systems on transparent or opaque film, in which the molding UV-hardening medium remains on a carrier film (substrate) after degeneration and where the bond can be strengthened by an additional adhesion promoter (polymer) applied to the substrate The product forms 2 and 3 are predominantly and the product shape 1 is partially fitted self-adhesive and processed to form decorative films as sheets or rolls or therefrom punched and cut bands to holographic or diffractive products such as images, labels, stickers, marking and adhesive ^¬.

4. Heißsieαelfolien and other transfer films in which a release layer (release coating) was first brought to the carrier film to ^¬ between the forming medium and the carrier film instead of Haftvermittiers in this case. This separating layer has a lower tactility to the UV-curing molding medium than the heat seal adhesive or transfer adhesive to the printing material applied to the molding medium and the metal layer after the metallization. which ensures that the very thin motif-bearing form layer is detached from the support and that this very thin motif-bearing form layer is permanently attached to the new printing material.

5. Textile. Fabrics, dimensionally stable fine fabrics (e.g. microfibers, nylon, polyester) for technical applications as well as applications in the area of security. Fashion and decoration. In this product form, a relatively strong (heavy) layer of soft / elastically curing pre-varnish is used in order to maintain the flexible textile character on the one hand and to ensure a smooth surface for taking up the holographic fine structure on the other hand.

Since it is preferred to provide a radiation source in the interior of the printing cylinder, it is necessary to make the printing cylinder and possibly its carrier transparent to radiation.

The impression matrix can be produced (shaped) as a cylinder sleeve or an endless belt loop, and or or glued or ultrasonically welded.

In a preferred method, the transparent. UV-permeable impression matrices fixed on the radiation-permeable printing cylinder by means of optically clear liquid adhesive or by means of optically clear transfer adhesive. Experience has shown that matrices should be manufactured as foils or wrapping plates in thicknesses from 50 my to 250 my

According to another preferred method, the cylinder sleeve or Banc.chleife is first cast on the inside of a structure-bearing negative forme cylinder

This impression can be made using infrared-curing, chemically curing (2 components) or preferably using UV-curing media. The curing takes place by irradiation from the inside of the negative ^cylinder

To achieve a uniform wall thickness and smoothness of the inner surface of the OF INVENTION ^¬ dungsgemaß to be generated Matπze to ensure that formaufneh¬ Mende medium, soft can after shaping the Matπze as a sleeve or tape schieife forms, by spin coating, that is by means of rotation of the Negativformzyhn- id. be applied

The layer thickness of the molding medium (the later mattress) is between 50 and 250 my or more, according to the requirements of further processing

The special feature of the matrix or the molding medium is its transparency to UV radiation

The structure to be molded is molded in advance in foils or thin plates from the surface relief hologram, which are fixed on the inside of the negative-form cylinder.

The negative forme cylinder can consist of at least two or more cylinder cheeks (partial cylinders) which can be opened (unfolded) after the hardening of the positive sleeve forming the die for molding

However, the positive pulse can also be removed from the inner surface of the vacuum cylinder by means of a vacuum suction device In order to facilitate the molding and structures ^¬ a Verkiammerung fine to avoid, may polysiloxane 0.2 to 2 weight percent release agents, for example hydroxylated, type Q4-3667 from Dow Corning, USA or pur additive 6845 or 6890 of Pura International, Germany, Impression medium are added

The cylinder sleeve (template) .derart prepared is then shrunk onto the Druckzy ^¬ relieving, or the printing cylinder is temporarily shrunk by cooling in nitrogen, for example, before the pushing of the sleeve. After RETRY ^¬ system reaching the normal temperature and thus re-expansion cylinder the Hüise has a tight fit. On the other hand, the pressure cylinder expands during printing by partial absorption of the UV radiation and conversion into heat also to the extent of. that the sleeve has a tight fit. And finally, this can also be glued.

The cylinder sleeve (die) can also be manufactured in a larger circular circumference, so that it forms an endless loop. This is guided around the printing cylinder and around an additional roller, by means of which an adjustable web tension of the endless loop is ensured.

An important criterion when determining the outer circumference of the printing cylinder / sleeve system or the belt loop / printing cylinder / tensioning roller system should be to choose a dimension which is one or more times the length of the printed image or the cylinder circumference of the various rotative ones Further processing machines in the graphic arts industry. This can e.g. Rotary printing machines or rotary punching machines. Laminating machines or combinations of the machines mentioned.

The usual print image lengths or roll developments are mostly single or multiple of the 12-inch system or the 24-inch system

However, the cylinder sleeve (die) can also be molded directly on the positive cylinder, as described below: In this further preferred method, the smooth printing cylinder is first placed concentrically in the original negative form cylinder. The space between the inner wall of the negative form cylinder and the surface of the printing cylinder corresponds to the wall thickness of the cylinder sleeve produced in the process

The negative mold and the positive cylinder cylinders to maintain a constant wall thickness of the medium-molding sten to ensu ^¬ concentrically positioned on ei ^¬ ner common axis

The sum of the double of the net Hulsenwandstarke pius diameter of the pressure cylinder corresponds to the gross diameter of the positive mold cylinder which with ^~ \ the desired repeat length multiplied (processing) or

Print image length results

The UV curing of the die is preferably carried out by irradiation from the inside of the UV-permeable positive cylinder. The production of the cylindrical sleeve (die) according to this method has the essential advantage that the sleeve is thus applied directly and completely seamlessly to the printing cylinder and can stay there

After printing, however, these sleeves produced according to the invention are very easy to remove again and the cylinder can again be provided with another sleeve, since they essentially consist of plastic with a smaller thickness

It is just as easy to snort them in advance. Remove the matrices attached to the cylinder as winding plates, after which the printing cylinder can again be equipped with other matrices

In order to achieve a firmer guidance of the printing materials on the cylinder during the wrapping thereof through the web of the printing material and thus during the molding process, an additional flexible belt loop can be used in the roller system if required

The web tension of this belt loop can be regulated, for example, by means of spindles or a tensioning roller mounted in a kissing system The radiation angle of the UV radiation source arranged in the impression cylinder can be varied by means of overlapping round and concentrically arranged diaphragms. Likewise, the UV radiation can be focused to a greater or lesser extent by an adjustable concave mirror in axis length, which is also arranged in the forme cylinder.

The invention is explained in more detail below on the basis of exemplary embodiments. Show it:

Fg 1 is a sectional view through the layer structure of Heißsiegelholo ^¬ program according to the prior art,

2 shows a sectional view of the layer structure of a printing substrate constructed according to the invention,

3 is an enlarged view of a surface layer section,

4 shows a schematic view of a printing device,

5 shows an alternative printing device with a shape-retaining endless belt loop,

6 shows a printing system with a plurality of printing units connected in series, and

Fig. 7 process diagrams for producing a printing cylinder.

Fig. 1 shows the structure of an embossing film in the so-called 'ißeißsiegeltechnik' according to the prior art. Such a film is produced in such a way that a thin wax or silicone-containing separating layer (2) is applied to a polyester web (1) of about 12 to 25 my thickness, on which a lacquer layer (3) of 0.9 is then applied up to 2.5 my (or 1.1 - 3.25 g / sqm) and then a 0.05 to 0.2 my metallic reflection layer (4), such as Aluminum is applied. 300 angstroms gives a good optical density of 1.8 - 2.

The hologram is embossed into the lacquer layer (3) by the metallization (4) as a so-called embossed hologram, which is usually present as a relief structure in an embossing die made of nickel. Anεchließend carried the A. FINISH emeε temperature activatable adhesive (5) (hot-melt adhesive), 0.7 g / m² by means of which the information-carrying layer lacquer ^¬ is transferred to the substrate and fixed there

To apply the "heat seal hologram, the film produced in this way is brought into intimate contact with a printing material, for example paper or cardboard, under the action of heat, for example 110.degree. C. to 130.degree. C. and pressure, for example 50-150 KP / cm and more the hot-melt adhesive (5) melts and the separating layer (2) is activated, resulting in a permanent connection of the lacquer / metal coating layer (3/4) to the substrate

Finally, the polyester film (1) is separated at the separating layer (2) so that only the varnish layer (3) is left on the printing material. the metallization (4) and the hot melt adhesive (5) remain

It should be pointed out that in this variant of the method the hologram is embossed from the side of the metallization (4) and the embossing plate can therefore be produced in the correct orientation. so that when viewed later, the hologram is seen in the correct direction through the clear lacquer layer (3)

2 shows the structure of a hologram on a carrier (6) which was applied according to the method of DE A 37 44 650. The carrier (6) is paper or cardboard. However, it can also be clear or opaque plastic or another be our carrier

A high surface smoothness of the wearer is desirable in order to achieve complete expression and thus good modulation and diffraction efficiency of the hologram to be applied

If this is not the case, the embossing or molding leads to "orange-skin-like distributions of pronounced and non-pronounced areas, as well as to a matt, blurred and diffusely reflecting surface and defective overall sanctity Unevenness in the density and in the thickness of the print substrate have been compensated to some extent by means of flexible Gegendruckwaizen from ^¬. In the case of the counter-pressure rollers or molds, for example Sili ^¬ kongummi or similar coatings could have. These should erfahrungsge ^¬ Mäss a Shore hardness of 60 to 90 have

Available on the market so-called "art printing papers and boards" such as may be suitable as a carrier for purposes of the invention, since they have the bottom line of the surface of a pre-compressed "core" and a good surface quality grout due to a machine coated or gußge ^¬ underlined coating

The substrate (6) should preferably have a machine-coated or cast-coated surface (10) as a background for the impression lacquer (7) to be applied and the smooth pre-coat to be applied, in order to close the pores and to improve the surface quality . to optimize the smoothness and roughness.

The necessary pre-smoothing of the surface takes place during the hardening of the pre-lacquer by molding from a polished cylinder or a smooth endless belt loop or from a smooth cover sheet. which is removed again after hardening.

The radiation-curing impression lacquer (7) is preferably applied with a thickness of 1.5 to 2 μm onto the smooth or pre-hardened surface of the carrier (6) or the line (10). The line (10) possibly applied to the carrier (6) and the possibly applied pre-lacquer effectively prevent the lacquer from striking away in the carrier (6) and bring about an optimally flat surface of the carrier

Because of the extreme delicacy of the structures to be embossed with a depth of embossing between 200 nm and 1,000 nm and a resolution between 800 and 1,800 lines per millimeter, it is absolutely necessary to compensate for any remaining surface irregularities with the thickness of the radiation-curing impression lacquer layer. Depending on the surface structure of the printing material or depending on the use of pre-lacquer, the thickness of the pre-lacquer layer can be from 2 g to 10 g / sqm or up to 20 g / sqm, experience has shown that paint layers of 1.5 to 15 my thickness are applied depending on the surface ^finish .

A mirror-like flat surface of a pre-lacquer layer is preferably achieved on a polished cylinder during curing or drying

The impression method according to the invention is based on the impression and curing of the lacquer and the fine structures in K act with the die. ^¬ tape loop. Cylinder sleeve or roller, preference being given to using radiation-curing lacquers

The curing or crosslinking can be triggered and carried out by ultraviolet or electron beam curing

Finally, a 20 to 200 nm thick metallization (8) is applied to the shape-bearing lacquer layer. e.g. Aluminum, applied, which causes the reflection of the viewing light of the hologram, and with a thickness of e.g. 300 Angstrom has a good optical density or reflection.

The metallization is preferably applied after the hologram structures have been molded.

When using a smoothing pre-varnish or with an already mirror-smooth surface of the printing material, e.g. in the case of plastic films, the metallization can also be applied to the primer.

The embossing is done with opaque, i.e. opaque substrates so that the embossing stamp has to be prepared upside down

For later protection of the hologram surface, a protective lacquer (9) or some other transparent part can then be applied to the metallization layer (8). colored, protective layer can be applied The method according to the invention results in a hologram carrier which is produced in direct method steps

In contrast to the prior art, in which the embossing an¬ must be keyed to transfer exchangers in a can by the erfindungsge ^¬ dimensions method a direct molding in the Bedruckεtoff done this he ^¬ gives a very high cost savings and a significant acceleration of Printing process

In the preferred embodiment of the invention, the varnish (7) consists of one or two different layers, the first varnish layer applied to the printing material or to the cast layer (10) to ensure a smooth surface finish. The sole or the second varnish layer carries the information

The metallization (8) is preferably evaporated onto the lacquer layer, but it can also be applied in another way, for example by means of indirect transfer metallization, provided the hologram structure is transferred after the metallization

In addition to the task of effecting the light reflection, the previous metallicization (8) has the advantage of enabling an immediate optical quality control of the stamping result after visual inspection or measurement of the diffraction efficiency or reflection during the impression

In one plant, the process according to the invention was able to achieve between 5,000 and 25,000 prints per hour and more

3 shows an enlarged sectional view between the actual layers carrying the hologram. The shaded area corresponds to the depth of the shape of the reflective structure of the hologram. It can be seen that the deepest point of the impression ends within the lacquer layer (7). The lacquer layer (7) is therefore to be chosen in a thickness that the molded reef structure does not penetrate into the carrier The lacquer layer (7) should also be selected so strongly that it is still possible to compensate for any remaining unevenness in the support (6) or the surface coating (10).

In addition to holograms other hchtbeugende structures and so-called. Diffraction grating or diffraction grating, for example, were mechanically or cut through La ^¬ sergravur and engraved, can be impressed

At sufficiently high surface quality, which is essentially determined by the layer structure of the printed material, written procedure yields εich after be here ^¬ the possibility of direct mass reproduction at much lower cost than in the previously described three-stage Ver ^¬ depart from Impression, adhesive coating and application on the printing or ^¬ after direct but hardware intensive processes, the electron beam hartung

4 shows a schematic view of a device for replication and simultaneous application of a hologram to a printing material.

A uniform surface quality is present on a roller (11) and the printing material is drawn off via a pair of rollers (16, 17). The printing material is passed over a further pair of rollers (22.23) over the printing cylinder (14), which is wrapped over about 180 ° or less. The printing material is then passed over a pair of rollers (30, 31). a further pair of rollers (24, 25) and between two rollers (18, 19) are fed to a winding roller (13).

If a carrier material is used, it can be guided as a web (37) together with the printing material through the application device and wound onto the roller (12) over the pairs of rollers (26, 27) and between two rollers (21.22).

To increase the pressure of the printing material on the printing cylinder, it can be provided that a ribbon loop (15) is guided together with the printing material over the surface of the printing cylinder (14). The ribbon loop around runs the rollers (23, 30, 29, and 28) and, if necessary, can also be guided under a tension roller (36), which serves to regulate the web tension

A lacquer ^¬ is layered on the printing cylinder or optionally on roller (23) to the web on ^¬ an applicator unit (34) with an applicator roller (35) supported, which then during the rotation of the printing cylinder between the roller (23) and the impression cylinder and printing arrives

The pressure cylinder (14) is formed as a quartz or Akrylglaszylmder (PMMA) from ^¬ and internally comprises a radiation source (33), in particular a UV light source on. For directed light output, a parabolic concave mirror (39) and apertures (38) are provided which are designed adjustable and adjust the region of influence of UV light on the guided over the impression cylinder Be ^¬ printing material.

If the radiation is focused on a more or less wide strip or slot, the wrap angle of the printing material around the printing cylinder can be reduced accordingly

The interior of the pressure cylinder is provided with a ventilation device, which on the one hand supplies cooling air and on the other hand provides for ozone extraction

To achieve a higher degree of efficiency, a water-cooled burner tube can be used.

Since the lacquer applied over the application roller (35) can be hardened by radiation. it hardens already during the circulation of the printing material over the printing cylinder to such an extent that it can be easily passed over further rollers and can be wound up on the winding roll (13) or (12). without affecting the surface structure

Instead of a UV light source, an electron beam source with a matching lacquer system can also be used. What is common to the processes, however, is that a relatively low-viscosity coating system is applied to the printing material, which can be cured without significant pressure even during the molding on the die. special achieved since .1 inventive printing cylinder and the inventive die themselves are executed UV hchtdurchlasεig so that ei ^¬ ne curing can take place from the interior of the pressure cylinder forth

FIG. 5 shows an alternative device according to FIG. 4 in which a shape-retaining endless belt loop is used instead of a pressure cylinder

The endless belt loop (40) can take up several microstructures or print image lengths one after the other. It is guided over the printing cylinder (14) and a deflecting roller (41). This device allows a faster change of matrices in the printing unit. In addition, this variant can be easily adapted Different print image lengths take place without changing the printing cylinder

The application roller (35) in this case applies the lacquer directly to the endless belt loop (40). Otherwise, the device in FIG. 5 corresponds to the device in FIG. 4

6 shows a device consisting of several printing units. The individual printing units essentially correspond to the devices of FIG. 4 or 5. In this case, a pre-varnish is applied to the printing material in a first printing unit in order to smooth it sufficiently on its surface. The applied primer can also be cured by UV radiation

The actual application of the micro structure to the printing material takes place on the main printing unit (46). If desired, a second printing unit (47) can be connected, which is arranged in the opposite orientation to the main printing unit, thereby permitting printing on the back of the printing material

Dance rollers (42, 45) are provided to keep the band tension of the printing material constant and to enable corrections of the longitudinal registers in the web. Each printing unit is assigned an order unit (34 48 or 49) 7 schematically shows the process for producing a printing cylinder

At the bottom is the Glassubεtrat (54) with the exposed and ent ^¬ wound photoresist layer (53) which tains the Oberflachenεtrukturhologramm be¬ the UV hard Abformmedium end (52) is applied to the structured holographiεch Fotoresiεtschicht (53)

This is done by spray casting (nozzle application device, a series of proportioning nozzles with defined nozzle diameters moves linearly over the plate), by dipping, by spiral application or by casting and spinning

The layer thickness should be at least 2 my and thicker

A UV-transparent acrylic sheet or acrylic plate (PMMA) is positioned on the impression medium in close contact as a later carrier of the impression medium (51)

This plate or film must be flexible in order to make it easier to detach it after it has hardened and to facilitate the further assembly and reproduction steps

A likewise UV-transparent quartz glass plate (50) is positioned on the acrylic sheet (51) in order to ensure absolute flatness and intimate contact of the acrylic sheet (54) with the impression medium (52) by means of uniform pressure

This molding or copying process is preferably carried out in a vacuum copying frame in order to ensure optimal contact of the copying layer and to avoid air inclusions

After the copying process by means of UV exposure, the acrylic film is detached from the photoresist and either copied repeatedly for the purpose of multiple-use copies (going up) or fitted into the negative form cylinder

This acrylic and impression medium sandwich is now inserted into the interior of a negative receptacle (55). which preferably consists of four shaped jaws connected to one another via joints (56 - 58) after closing the Neqativformaufnahme (55) is the Abformmedium as "internal coating within deε Hohlzyhnders Now, a quartz glass cylinder (54) inserted concentrically into the negative mold receptor (55) The corresponding procedural ^¬ rensschritt is shown in Figure 7d

Ng 7e shows the device for producing the printing roller. An impression varnish provided in a tank (59) is introduced via pipes (60) into the space between the glass cylinder (54) and the photoresist (52). The filling of the intermediate space and degassing is carried out by a connected one Vacuum (61) supports The impression lacquer is cured by means of UV light, a corresponding light source being provided within the glass cylinder (54)

After the impression lacquer has hardened. the negative mold holder can be opened and the printing cylinder (62) can be removed. This then bears on its surface the microstructure generated via the photoresist (52)

After the printing cylinder (62) has been inserted into a printing unit, the printing material can actually be printed

Reference list

1 polyester support

2 separation layer

3 lacquer

4 metallization

5 hot melt adhesives

6 carriers. Substrate

7 lacquer

8 metallization

9 protective varnish

10 cast line

11 roller

12 roller

13 take-up roll

14 printing cylinders

15 belt loop 16.17 pair of rollers 18.19 pair of rollers 20.21 pair of rollers 22.23 pair of rollers 24.25 pair of rollers 26.27 pair of rollers 28.29 pair of rollers 30.31 pair of rollers

32 roller

33 radiation source

34 commissioned work

35 application roller

36 tension roller

37 lane

38 apertures

39 concave mirror

40 Endloεbandschleife

41 roller 42.45 dancer rollers 46 main pressure ..

47 back pressure unit

48 Commissioned work

49 Commissioned work

50 quartz glass plate

51 acrylic sheet

52 UV-curing impression medium

53 photoresist

54 glass substrate

55 glass cylinders

56 Negative image

57.59 joints

60 tank

61 pipes

62 Vacuum connection

63 printing cylinders

Claims

Expectations

1 Method for simultaneous rephcation and direct application of a microstructure, in particular a hologram or another diffraction grating, to a printing material (6), in particular paper or cardboard, in the impression process using a matrix which carries the microstructure as a surface relief structure , in which one or more lacquer layers (3, 7, 9) are applied to a printing material (6), through which the surface of the printing material (6) is smoothed, and in which the hologram into the surface of the on the printing material ( 6) applied coating is molded, characterized in that at least the lacquer layer (3) receiving the microstructure is radiation-hardenable, in particular UV-hardenable, and the hardening of the lacquer layer (3) from the die side by the radiation-transparent mattress and the shape ¬ cylinder or the Matπzentrager (14) through

A method according to claim 1, characterized in that the hardening of the lacquer layer (3) takes place essentially before the printing material (6) is removed from the die in contact with the die

Method according to claim 1, characterized in that when using a rotation method, the radiation hardening of the lacquer layer (3) takes place during the circulation of the printing material (6) around a forme cylinder through the forme cylinder wall, a radiation source (33) in the interior of the radiation-permeable forme cylinder. for curing the lacquer layer (3) receiving the microstructure

Method according to claim 1, characterized in that the radiation source (33) is a UV radiation source or an electron beam source

A method according to claim 1, characterized in that the UV-transparent impression matrix is designed as a single matrix, as an endless belt loop, as a cylinder or as a cylinder sleeve

Method according to Anεoruch 1, characterized in that the radiation hardening waste medium has a release agent of 0.2 to 2 percent by weight is added to enable loosening of the outgoing mold medium and to prevent the holographic positive / negative fine structures from jamming

Method according to claim 6, characterized in that the release agent is chemically adjusted in such a way that the hardening impression medium has a substantially greater adhesion to the printing material than to the matrix

Printing material for use as a support of a microstructure in a method according to claim 1, characterized in that the printing material (6) is a clear or opaque plastic film or plastic paper

Printing material according to the preamble of claim 8, characterized gekenn¬ characterized in that the printing material (6) is polyester paper

Printing material according to the preamble of claim 8, characterized in that the printing material (6) is made of textile, in particular dimensionally stable fine tissue made of plastic

Printing material according to the preamble of claim 8, characterized in that the printing material (6) is a smooth film which, during the molding and hardening process, serves as a carrier for the production of a self-supporting film which absorbs the microstructure and which, after being removed curing of the self-supporting film is separated from it and, if necessary, rolled up again for re-use

Printing material according to claim 11, characterized in that a heat-activated release agent is applied to a polyester support, to which a radiation-hardenable lacquer (3) is applied, and in that the lacquer layer during the action of a matrix carrying the microstructure on the lacquer layer by radiation , in particular UV or electron radiation cured

Printing material according to claim 12, characterized in that the separating layer (2) is formed as a wax-containing or separating separating layer 14. Printing material according to one of claims 8 - 13, characterized in that after the impression of the hologram structure, a reflective Metalli¬ sierung (4) is applied to the lacquer layer (3).

15. Printing material according to claim 14, characterized in that after the molding of the hologram structure and after metallization (4), a transparent, clear or colored protective lacquer layer (9) is applied to the surface of the metallized hologram and smoothed.

16. Printing material or method according to claim 15, characterized. that the protective or colored lacquer layer (9) is radiation-curable, in particular UV-curable.

17. Printing material according to one or more of claims 8-13, characterized in that a reflective metallization (4) is applied to a first smoothed lacquer layer (3) or filler layer and the hoiogram structure in a second lacquer layer before the hologram structure is molded (7) is introduced.

18. Device for applying a hologram to a printing material (6), in particular paper or cardboard, for carrying out the method according to claim 1, characterized in that the web-shaped printing material (6) via a cylindrical matrix carrying the hologram as a surface relief structure and that the matrix is assigned a radiation source (33), in particular a UV radiation source, by means of which a radiation-curing lacquer layer (3) applied to the printing material (6) is cured during contact with the matrix.

19. Device according to claim 18, characterized in that the radiation source hardens the lacquer layer (3) from the front of the printing material.

20. Device according to claim 19, characterized in that the radiation source (33) is located inside the printing cylinder (63) and that the lacquer layer (3) is cured through the εradiation-permeable printing cylinder (63) and the radiation-permeable matrix. Device according to claim 18, characterized in that the radiation source (33) is an ultraviolet light source or an electron beam source

Device according to claim 20, characterized in that the printing cylinder (63) or the mattress holder is formed in the white UV-transparent quartz glass

Device according to claim 20, characterized in that the pressure cylinder (63) or the matrix holder essentially consists of plastic, in particular UV-transparent acrylic glass (polymethyl acrylate, PMM)

Device according to claim 20, characterized in that the beam path of the UV light source can be configured so as to be adjustable by means of optical reflectors, diaphragms (38) and / or focusing devices

Device according to Claim 18, characterized in that the device consists of one, two or more printing units (46, 47) arranged one after the other or these can be retrofitted in a modular manner

Device according to claim 18, characterized in that two oppositely arranged printing units (46 47) simultaneously print the web on the front and back with precise register