DE102008061998A1 - Method for manufacturing embossing roller for planishing tool to form diffraction effect-images, involves corroding areas of sheet metal up to pre-determined corroding depth, so that sheet metal is optionally bent to form cylinder section - Google Patents

Abstract

The method involves coating a sheet metal i.e. stainless steel sheet, with a photo resist, and exposing the photo resist coating to a line pattern corresponding to a diffraction effect. An exposed or unexposed area of the photo resist coating is removed. The areas of the sheet metal are corroded free from the photo resist coating upto a pre-determined corroding depth by a hydrochloric acid solution, so that the sheet metal is provided with a groove pattern and optionally bent to form a cylinder section, where the hydrochloric acid solution is provided with iron ferric chloride. Independent claims are also included for the following: (1) a diffraction pattern embossing roller including a forming die forming cylinder section (2) a method for producing diffraction effect images.

Description

The The present invention relates to a stamping plate and roll for the production of diffraction effect images, a method for producing such images, and a method for manufacturing such a stamping plate or roller.

holograms, Kinegrams or similar, based on diffraction effects Elements set on the basis of their with changing the viewing angle occurring brightness change game or color change game as well the possibility of viewing angle dependent readable Store and display information, a popular identifier Among other things, because the optically variable effect by simple Copying can not be reproduced.

From the patent application DE 196 27 638 A1 For example, a method of manufacturing a cylindrical die for such diffraction effect images is known in which a cylindrical surface of a thermoplastic material is provided with the desired embossing pattern and then electroplated.

From the German patent DE 101 46 635 B4 For example, there is known a method of making a sheet material provided with diffractive effect images, in which the desired image is imprinted directly into a metal layer of the sheet material so that the metal forms the outer layer.

The conventional process for the production of embossing rolls for purposes of producing diffraction effect images felt too expensive; especially in cases where often changing motifs in rapid succession that is, where diffraction effect images are primarily aesthetic Serve purpose, z. B. the visual enhancement of a product, wherein also the feel should be pleasant.

The known methods for producing the diffraction effect images themselves are, according to the inadequacies of the used Embossing rollers, insufficiently applicable to mass use and / or lead to less appealing products.

It is therefore an object of the present invention, the known Processes and devices educate so that a mass use same is facilitated.

To the invention provides the method according to claim 1, 14 and 21, and the embossing roll according to claim 10 ready.

Under In a first aspect, a method of manufacturing an embossing roll is disclosed for diffraction effect images, an etching step, and a bending step of the etched sheet to a cylinder portion on. This indicates a sequence of processes that is a particular cost efficient provision of change embossing patterns allows. This can be dispensed with the bending step be, for. B. when the stamping used in a flat punch shall be.

For etching a steel sheet in embodiments becomes a hydrochloric acid Solution of ferric chloride used, the etch depth by stopping the etching process with an alkali after one predetermined etching time in response to a predetermined etching temperature is determined. The line pattern has in embodiments a set of lines equidistant from each other, where the lines of the crowd to each other laterally offset zigzag lines his and her distance from each other in a range of 0.2 to 1 mm, with the individual lines of the line pattern each have a width of 0.02 to less than 0.2 mm.

The diffraction effect in embodiments is that the relative reflection angle-related intensity of light reflected from the groove pattern of a reference wavelength in a reference plane perpendicular to the groove pattern has at least two maxima and a minimum between the maxima. On the other hand, in the case of an unstructured surface, the reflection is maximum in the direction of the angle of incidence opposite to the incident angle, and decreases on both sides thereof with respect to the plane spanned by incident and failures. The rougher the surface, the flatter the reflection light distribution; but additional maxima occur only by suitable structuring, namely by mutually equidistant line shares, which cause by their diffraction effect a light / dark variation with multiple maxima in dependence on the measured angle in the reference plane. In embodiments, the pattern further reflects incident light such that light reflected in a first half-space bounded by the reference plane is provided a different view than in a second light reflected from the first opposing half-space. As a result, in addition to the light / dark change and a change between two different images, such as a company name and the company logo, provided, as in other ways according to the document GB 2 306 404 A or the publication DE 103 37 452 was achieved.

In a second aspect, an embossing effect image embossing roller has an embossing mold forming a cylinder portion and a receptacle for holding the embossing mold at a predetermined distance from the roller axis. Thus, an embossing roll is given, which also provides a particularly cost-efficient provision of Wech sel-embossing patterns allows. In embodiments, the angle of the cylinder portion is at least 120 ° or 240 °, in some cases over 320 °. A seamless arrangement to the solid shell, corresponding to an angle of 360 °, is possible.

Further is a third aspect of a method for the production of Diffraction effect images indicated in which the desired Line pattern embossed in a metal layer or metallized layer and the embossed surface then with a plastic film is stuck. This process is also particularly cost-efficient Exchange embossing pattern ready because the pattern embossing and lamination can be done at high throughput speeds. Embossing and lamination are preferably carried out in two operations successively.

The Uncoated foil is in embodiments of a thermoplastic Plastic, in particular of polystyrene, polyvinylidene chloride, cellulose acetate, Polyvinyl acetate or a polyolefin, in particular of polypropylene or PVC, or a copolymer formed from these.

The embossed film may be on the one hand a metal foil, the no plastic included. The metal is in embodiments Aluminum. On the other hand, if a metal or aluminum vaporized Foil is used in embodiments includes one Polyester or polystyrene, polyvinylidene chloride, cellulose acetate, Polyvinyl acetate or a polyolefin, for example polypropylene or PVC, or a copolymer of these. In embodiments the film is a hot foil, which is for welding on a substrate before embossing is suitable. In a Another embodiment is the embossing substrate formed by a varnish in desired areas an object, for example one from a paper or cardboard sheet applied substrate is cured and cured, so that in the substantially cured lacquer the pattern can be shaped. The paint is in embodiments to a UV varnish, which cured by means of UV exposure becomes.

In Embodiments includes the method before the actual Emboss the welding of the foil on a substrate.

Further advantageous embodiments, details and aspects of the invention result from the dependent claims, the Description and the accompanying drawings.

The The present invention will now be described with reference to the accompanying drawings explained in more detail. Show it:

1 a conventional embossing roll;

2 an embodiment of the present invention;

3 a scheme for the preparation of diffraction patterns;

4 an embodiment of a diffraction image; and.

5 an embossing roll according to the present invention.

1 shows a conventional embossing roll 11 in which in a thermoplastic material 12 a variety of sections with a line pattern 10 are impressed. The sections are equal to each other, as produced by the same die. As can be clearly seen, there are spacing areas without embossing between the embossed areas, so that no full-surface embossing with line patterns is possible, and thus no production of a large-area diffraction effect image.

According to the invention a (flat) steel sheet first with a photoresist coated S1. Depending on whether it is a positive-resist or is a negative resist, becomes the desired groove pattern or the web pattern exposed on S2 and the exposed or unexposed paint removed S3. This is done afterwards an etching process S4, for example with a heated, 0.04 molar hydrochloric acid iron (III) chloride solution (eg. 3.2 molar). After the expiration of the selected temperature (eg 40 ° C-90 ° C) for the desired etch depth decisive etching time (eg 3 min) becomes the process stopped with sodium hydroxide solution and the sheet was cleaned and dried. It is then clamped onto an embossing roll by a Holding the sheet in curved form S5 so on the roller attached, that it is everywhere the same distance from the roll axis has S6 and thus a perfect concentricity is possible. Alternatively, a flat punch is used, preferably with a heatable flat mounting plate for the etched Sheet metal with the groove or web pattern.

by the way are depending on the choice of the material of the sheet also other, in particular electroless etching possible. Here stainless steel was used. In one variant, aluminum is used and with about 11 molar phosphoric acid, with the addition of each about 1 molar nitric, hydrofluoric or acetic acid at 20 ° C to 50 ° C etched. It is respectively appropriate, the plate during the etching process z. B. to move in a rotary motion through the etching bath.

In one embodiment, the etched, cleaned and dried plate is screwed into a flat receptacle or onto a roller. A paper substrate is laminated with a film having a reflective layer and pressurized at a temperature of e.g. B. 80 ° C coined. The embossed structure is embossed into the reflective foil and the paper. Thereafter, the embossed substrate is laminated with a transparent film, resulting in a shimmering effect. However, this final lamination may be omitted in some applications, or replaced or supplemented by coating with a UV varnish. As the reflective layer, a metallized layer or a laminate of two layers having a greatly different refractive index may be used (for example, Δn> 0.3). In embodiments, the z. B. cured by UV light lacquer layer as a reflection layer.

In a variant, in a first step, a hot foil, So a partially coated with a heat-activated adhesive Foil, welded to a substrate S7. The activation worried about a 120 ° C hot brass stamp. However, even in an offset machine can be an adhesive in one Printing unit printed and then in a second printing the reflective Slide past it. In the places where glue is printed, then adheres the film. This not only allows full surface, but also partially the reflective film can be applied. In this arrangement is with the embossing roll or plate imprinted the line pattern S8, which consists of a sequence of laterally offset, partially straight zigzag grooves or webs. Subsequently, on the embossed Glued on a glossy film S9, with the adhesive in the grooves or between the webs of the embossing pattern runs. The outside of the laminate is therefore smooth and offers an appealing haptic, while the motif shown depending on the viewing angle between different representations and / or varying light / dark distribution changes. Also a Color change play is with sufficient precision of the line pattern possible.

Furthermore the line pattern does not necessarily have to consist of continuous zigzag lines consist; it is sufficient if there are crowds of people in neighboring areas arranged angled to each other. Each lineage stops their own reflection profile ready, namely a destructive Interference perpendicular to the line direction at an angle from the Wavelength of light, angle of incidence and line spacing depends. The adjacent area with another line angle (in the area) and, where appropriate, distance indicates accordingly of which different reflection profile, in particular a different angle, below that the destructive interference on the basis of the intensity minimum is recognizable. For example, the lineages are arranged so to recognize a company name from diagonally right is bright to dark, or vice versa, depending on the top / bottom tilt angle; and viewed from diagonally to the left, the corresponding one Company logo, again bright, depending on the top / bottom tilt angle bright to dark or the other way around.

This scheme is in 3 shown. In this example, the non-motif areas (backgrounds) are formed by areas in which the line group forms angles of 45 ° (angle 1) and 112.5 ° (angle 2) to the horizontal reference direction (dot-dashed lines). In the areas in which the first motif should appear, the angle is 135 ° (angle 4); in the area assigned to the second motif, the angle is 67.5 ° (angle 3). Thus, the minimum angular distance Δφ (angle 3 - angle 1) is 22.5 °. Because of the symmetry of the arrangement to the reference direction in this example, the angular distance between angle 4 and angle 2 is just as large. The angles specified here are to be understood as merely exemplary and not restrictive.

In the example of 4 Two boxes are created with commercially available graphics software, one per motif. In these boxes you draw cross lines with, for example, 0.08 mm thickness and 0.3 mm grid spacing. In one box, the background lines have an angle of 75 °, in the other of 285 ° (or what is the same, 105 °) to the reference direction. In the parts which are to represent motifs ("A" or "B"), one draws lines at an angle of 25 ° or 155 ° in the second box; possible would be 55 ° or 125 °. Then put both boxes in strips at pitch P next to and / or above each other. The later embossed bow shows either one motif ("A") in front of its background (a), or the other ("B"), depending on how one views the embossed substrate. The angular distance between the lines of lines should be at least 20 °, in some applications at least 30 °, or at least 40 °, so that the motifs are clearly visible in front of their respective background (a, b). In embodiments, the angles are selected in pairs symmetrically to a reference direction. The pairs can be formed by a motif and its background, the motifs or backgrounds among each other or by one motif and the background of the other motif (and vice versa). It is also possible that a background itself represents a (larger) motif.

In the 5 is schematically an embossing roll 1 according to the invention (together with the backing roll 3 ). As can be seen, is a receptacle for the etched sheet on its peripheral surface 2 educated. In this example, the circumferential angle of the recording is about 300 °; but it can also be more, for example 320 ° to 360 °, or less, for example from 240 °. Even smaller angles are possible, especially those in which two sheets are clamped in two separate shots, so for example, 120 ° to 180 °. The receiving and holding device comprises in the example shown holding screws 7 ; However, other recording mechanisms are possible. In the 3 is instead of the cylinder angle φ of the recording its opposite angle φ '= 360 ° - φ located, as well as the roller rotation axis 4 , The axis of rotation of the counter roll 3 is with 5 indexed and expediently to the axis of rotation 4 the embossing roller parallel. The counter roll 3 is expedient with a rubber pad 6 equipped. Thus, an assembly of paper backing and aluminum foil or aluminized polyester film under pressure through the nip thus formed 8th kick, as the rubber pad 6 has a certain elastic compliance. This pressure causes the embossing of the respective reflective layer. After loosening the retaining screw 7 can the sheet 2 axially from the embossing roll 1 removed and, if desired, replaced by another sheet with a different line pattern.

The The invention thus provides an embossing plate or roller, a Manufacturing method for such and a manufacturing method ready for diffraction-effect-based images that little consuming and therefore cost-effective for short-term changing motif needs are applicable. The following Claims are intended as a non-limiting attempt of description to understand the invention in general terms.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19627638 A1 [0003]
• - DE 10146635 B4 [0004]
• GB 2306404 A [0011]
• - DE 10337452 [0011]

Claims (26)

Method for producing a stamping mold, in particular roller for diffraction effect images, comprising: - coating a sheet with a photoresist; - Exposing the photoresist coating with a line pattern corresponding to the diffraction effect; - Remove either the exposed or unexposed areas of the photoresist coating; - etching the areas of the sheet removed from the photoresist coating until to a predetermined etching depth, so that the sheet a Groove pattern receives; and optional - To bend of the sheet to a cylinder section. The method of claim 1, wherein for etching a hydrochloric acid solution of iron (III) chloride is used and the sheet is a stainless steel sheet. The method of claim 2 wherein the etch depth is through Stopping the etching process with an alkali after a predetermined etching time in response to a predetermined etching temperature is determined. Method according to one of claims 1 to 3, wherein the line pattern is like a family of lines Distance has. The method of claim 4, wherein the lines of the crowd are laterally offset zigzag lines. The method of claim 5, wherein the lateral offset is in a range of 0.2 to 1 mm. Method according to one of claims 1 to 6, wherein the individual lines of the line pattern each have a width from 0.02 to less than 0.2 mm. Method according to one of claims 1 to 7, wherein the diffraction effect is that the relative reflection angle-related Intensity of light reflected from the groove pattern a reference wavelength in a direction perpendicular to the groove pattern Reference plane at least two maxima and one lying between the maxima Minimum. The method of claim 8, wherein the groove pattern further incident light reflected such that in a first a half-space reflected light from the reference plane provides a different view than in a second, the first opposite Half-space reflected light. Diffraction pattern embossing roll comprising: - one a cylinder portion forming embossing mold with at least an etched crowd laterally gleichabständig each other offset sections of straight grooves or webs, preferably to form a zigzag pattern; and - An embossing mold recording for repeatedly detachable attachment of the stamping mold at a predetermined distance to a roller rotation axis. An embossing roll according to claim 10, wherein the Cylinder section is more than one third of a cylinder. An embossing roll according to claim 11, wherein the Cylinder section is more than two-thirds of a cylinder. An embossing roll according to claim 12, wherein the Cylinder section is more than eight-ninth of a cylinder. Method for producing diffraction effect images, full: - Embossing of the diffraction effect corresponding line pattern in a metal foil or in a metallevaporte Plastic film; and - Gluing a uncoated plastic film on the embossed side of the metal foil or metallized plastic film with an embossed line pattern filling Adhesive. The method of claim 14, wherein for embossing the embossing roll according to one of claims 10 to 13 is used. The method of claim 14 or 15, wherein the uncoated Foil of a thermoplastic, in particular of polystyrene, Polyvinylidene chloride, cellulose acetate, polyvinyl acetate or / and a Polyolefin, in particular of polypropylene or PVC, particularly preferred of flexible PVC, or / and a copolymer of these and in particular a plasticizer is formed. Method according to one of claims 14 to 16, wherein the metal is aluminum. Method according to one of claims 14 to 17, wherein the metallized plastic film comprises a polyester. Method according to one of claims 14 to 18, further comprising welding the film to a substrate the embossing. The method of claim 19, wherein the film is only partially, preferably less than half of the total area welded to the substrate. A method of producing a diffraction image, comprising Applying a paint to a substrate, solidifying the paint, and embossing the diffraction pattern in the solidified paint. The method of claim 21, wherein the paint is only partially, preferably less than half of the total area is applied to the substrate. A method according to claim 21 or 22, wherein the lacquer a UV varnish is. The method of claim 23, wherein solidifying includes exposure to UV light. Method according to one of claims 19 to 24, wherein the substrate is a paper or cardboard sheet or such is made. Diffraction effect image prepared by the method according to one of claims 14 to 25.