LAYER STRUCTURE FOR PRODUCING A HINGE, IN PARTICULAR FOR PRODUCING MULTI-LAYERED BOOK COVERS

Abstract

The present invention relates to a layer structure, preferably a hinge, particularly preferably a book cover, very particularly preferably a book cover for identification and security documents, comprising at least one outer layer a) containing at least one thermoplastic elastomer, preferably a thermoplastic polyurethane, and at least one layer b) containing at least one material selected from the group consisting of a polymer, a metal, a textile, a paper and a synthetic paper, or a combination of at least two of these, and also relates to a laminate comprising the above layer structure and to the method for producing same. The invention further relates to the use of the layer structure and/or laminate for the production of a hinge, preferably a multilayer book cover, especially for security and identification documents.

Claims

1. A layer structure, comprising at least one outer layer a) containing at least one thermoplastic elastomer, and at least one layer b) containing at least one material comprising a polymer, a metal, a textile, a paper and a synthetic paper, or a combination of at least two of these.

2. The layer structure as claimed in claim 1, wherein the layer structure has a length x and a width y, the at least one layer b) having at least one cutout of any desired form.

3. The layer structure as claimed in claim 2, wherein the at least one cutout in the layer b) has the form of a parallelogram which runs parallel to a line of symmetry of the length x or of the width y.

4. The layer structure as claimed in claim 2, wherein the at least one cutout in the layer b) is formed over a width of ≥0.1 mm to ≤100 mm, or wherein the cutout in layer b) is arranged in the form of at least two sections on the layer a), so that between the at least two sections at least one cutout which is not covered by the layer b) is formed on the layer a).

5. The layer structure as claimed in claim 1, wherein the at least one layer b) comprises at least one dye and/or at least one pigment; the layer b) optionally additionally comprising a print layer applied over the whole area and/or over a partial area.

6. The layer structure as claimed in claim 5, comprising the print layer applied to at least one layer b) over the whole area and/or over a partial area, and wherein the print layer points in a direction of the layer a).

7. The layer structure as claimed in claim 1, wherein the layer a) has a thickness in the range from ≥20 μm to ≤1000 μm.

8. The layer structure as claimed in claim 1, further comprising at least one further layer c) containing at least one thermoplastic polyurethane, which is formed at least in regions as a foam layer, and at least one further layer b′) containing at least one material comprising a polymer, a metal, a textile, a paper, a synthetic paper, or a combination of at least two of these.

9. The layer structure as claimed in claim 8, wherein at least one component and/or at least one functional unit is positioned on the at least one further layer b′).

10. The layer structure as claimed in claim 8, wherein the at least one further layer b′) further comprises a cutout of any desired form.

11. The layer structure as claimed in claim 8, further comprising at least one further layer d) containing at least one thermoplastic polyurethane having a hardness of ≥60 Shore A according to DIN ISO 7619-1 to ≤95 Shore D according to DIN ISO 7619-1, the layers of the layer structure being arranged so as to result in a sequence a) b) d) c) b′) or a) b) c) d) b′).

12. The layer structure as claimed in claim 11, wherein further comprising at least one further layer d′) comprising at least one thermoplastic polyurethane having a hardness of ≥60 Shore A according to DIN ISO 7619-1 to ≤95 Shore D according to DIN ISO 7619-1, the layers being arranged so as to result in a sequence a) b) d) c) d′) b′) or a) b) d′) c) d) b′).

13. A laminate comprising a layer structure as claimed in claim 1.

14. A method for the production of a hinge, comprising forming a hinge comprising the layer structure as claimed in claim 1.

15. A method for producing a multilayer laminate comprising: i) providing a layer structure as claimed in claim 1; ii) laminating the layer structure from step i) at a temperature of ≥80° C. to ≤220° C. and with a pressure of ≥2 N/cm.sup.2 to ≤500 N/cm.sup.2; iii) optionally folding the layer structure; iv) optionally pressing the layer structure after step iii) along a cutout in layer b) and possibly in a further layer b′); v) optionally removing the layer structure from the press.

16. The layer structure as claimed in claim 1, wherein the at least one thermoplastic elastomer is a thermoplastic polyurethane having a hardness of ≥60 Shore A according to DIN ISO 7619-1 to ≤95 Shore D according to DIN ISO 7619-1.

17. The method as claimed in claim 15, wherein laminating is performed with an engraved lamination plate.

Description

EXAMPLES

[0131] Raw Materials and Materials of the Individual Layers

[0132] Layer a)

[0133] The external TPU layer of a passport book cover (FIG. 1, layer a) was produced using an aliphatic polycaprolactone-based TPU having a Shore A hardness of 85-90 according to ASTM D2240 or DIN ISO 7619-1. The melt extrusion process was used to produce the TPU film. The TPU granules were melted in a melting extruder and extruded through a die to give a film in a thickness of 150 μm.

[0134] Layer b) and b′)

[0135] For the layers b) and b′) a 250 μm thick synthetic paper from PPG, sold under the trade name Teslin™ was used.

[0136] Film 1: 3-Layer Film with the Layer Sequence dcd′)

[0137] A three-layer thermoplastic polyurethane film with a thickness of 600 m was produced in the blown coextrusion process. The film consisted of three layers: the two outer plies d) each made of 100 μm compact thermoplastic polyurethane and the 400 m thick middle layer c) made of foamed thermoplastic polyurethane. The thermoplastic polyurethane used was a TPU based on polytetrahydrofuran (molecular weight 2000), methylene diphenylene 4,4′-diisocyanate and butane-1,4-diol as chain extender with a Shore A hardness of 87, measured to DIN ISO 7619-1, corresponding to a Shore D hardness of 36, measured to DIN ISO 7619-1, a density of 1.12 g/cm.sup.3 measured to DIN EN ISO 1183-1A and a melt flow index (MFI) of 30 g/10 min measured at 190° C./21.6 kg (DIN ISO 1133).

[0138] For the foaming of the middle layer c), 5% by weight of Hydrocerol™ CF20 from Clariant was added to the TPU, which releases CO.sub.2 in the course of heating of the film in the extruder and hence foamed the TPU on exit from the die.

[0139] Film 2: 2-Layer Film with the Layer Sequence (g-h) as an Alternative Layer a)

[0140] Layer (g-h)

[0141] The external layer a) in the form of a layer sequence (g-h) of a passport book cover as shown in FIG. 6 was produced using a polyether block amide (PEBA) for the layer (g) together with a TPU for the layer (h). The melt coextrusion process was used to produce layer a) in the form of the two-layer film (g-h). The PEBA granules and the TPU granules were melted in separate melting extruders at 190° C. to 200° C., preferably at 200° C., and extruded through a coextrusion die to give a film in a thickness of 150 μm.

Example 1: Passport Book Cover with TPU Exterior Layer with Coloring and Lettering

[0142] Layer b) was printed in color over the whole area of one face. Printing was performed by means of toner printing on an MP C3003 model printer from the manufacturer Ricoh. In addition to the color-imparting whole-area printing, the lettering “Passport” was printed on layer b) which had already been printed in color.

[0143] The layer a) was arranged such that it was in contact with the printed side of the layer b), so that the print was visible through the transparent layer a).

[0144] A line, where the passport book cover was intended to be folded later, was marked on layer b). The material of layer b) was removed along these fold lines in a width of 6 mm. For this, layer b) was placed in a Plator press and a 6 mm wide strip of material was stamped out along the fold line by means of a steel rule die.

[0145] Layers a) and b) were stacked according to FIG. 1) and fixed in their position by means of spot welding at the four sheet corners.

[0146] The stack of layers a) and b) was laminated on a Bürkle lamination press. The lamination plate that was in contact with layer a) was a lamination plate engraved over the whole area and having a non-stick coating. The engraving corresponded to a leather grain. The corresponding plate was supplied by the company 4-Plate.

[0147] Lamination Parameters:

[0148] Preheating of the press to 150° C.

[0149] Pressing for 5 minutes with a pressure of 20 N/cm.sup.2.

[0150] Cooling under a pressure of 150 N/cm.sup.2 until a temperature of 38° C. has been reached, and opening the press.

[0151] After removal of the laminate, the side which had been in contact with the engraved plate exhibited a uniform leather grain which was also able to be perceived as leather. The adhesion of all layers was particularly good, and hence a non-destructive separation and reuse of the layers was not possible. The separation of the layers was tested by attempting to separate the individual layers from each other by hand. The layers could only be separated using appropriate tools (scissors, pliers), which resulted in damage to the layers. The color print remained undamaged after the lamination and appeared with good brilliance through the transparent exterior layer a).

[0152] A passport book cover was stamped out from the laminate in the desired size. The stamped-out book cover was then folded along the stamped-out cutout of the fold line. The folded side of the book cover was then clamped in a roll laminator in a width of 4 mm along the entire length of the book cover. The book cover was clamped for a period of 3 seconds at a roller temperature of 130° C. The book cover was then removed from the rollers. This enabled a memory effect to be achieved in ply a): If the original form of the book cover was disturbed by opening the book cover, it closed again automatically (FIG. 2).

[0153] The book cover had a flat position of less than 5 mm, thus significantly better than the minimum value specified in ISO 18745-1.

Example 2: Passport Book Cover with Coloring and Lettering and Integrated Chip Module and Antenna

[0154] Layer b) was printed in color over the whole area of one face. Printing was performed by means of toner printing on an MP C3003 model printer from the manufacturer Ricoh. In addition to the color-imparting whole-area printing, the lettering “Passport” was printed on layer b) which had already been printed in color.

[0155] The layer a) was arranged such that it was in contact with the printed side of the layer b), so that the print was visible through the transparent layer a).

[0156] An antenna made of copper wire was placed on a further (unprinted) layer b′) (see also FIG. 3). The wire had a diameter of 80 μm and was formed into the form of an antenna f) in accordance with the standard ISO 14443 for contactless data transfer. A chip module e), suitable for data storage and contactless data transfer in accordance with the standard ISO 14443, was contacted with the ends of the antenna.

[0157] A line, where the passport book cover was intended to be folded, was marked on each of layers b) and b′). The material of layer b) and b′) was removed along the fold line in a width of 6 mm. For this, layers b) and b′) were placed in a Plator press and a 6 mm wide strip of material was stamped out along the fold line by means of a steel rule die.

[0158] The layers were stacked according to FIG. 3 and fixed in their position by means of spot welding at the four sheet corners.

[0159] The stack of films according to FIG. 3 was laminated on a Bürkle lamination press. The lamination plate that was in contact with layer a) was a lamination plate engraved over the whole area and having a non-stick coating. The engraving corresponded to a leather grain. The corresponding plate was supplied by the company 4-Plate.

[0160] Lamination Parameters:

[0161] Preheating of the press to 150° C.

[0162] Pressing for 5 minutes with a pressure of 20 N/cm.sup.2.

[0163] Cooling under a pressure of 150 N/cm.sup.2 until a temperature of 38° C. has been reached, and opening the press.

[0164] After removal of the laminate, the side which had been in contact with the engraved plate exhibited a uniform leather grain which was also able to be perceived as leather. The adhesion of all layers was particularly good, and hence a non-destructive separation and reuse of the layers was not possible. The separation of the layers was tested as described in example 1. The color print remained undamaged after the lamination and appeared with good brilliance through the transparent exterior layer a). The passport book cover further had a consistently homogeneous thickness distribution. Unevennesses due to the antenna that had been incorporated by lamination and the chip module were taken up and compensated by the ply dcd′), as shown schematically in FIG. 4.

[0165] The laminates were stamped in the size of a passport book cover. The stamped-out book cover was then folded along the stamped-out cutout of the fold line. The folded side of the book cover was then clamped in a roll laminator in a width of 4 mm along the entire length of the book cover. The book cover was clamped for a period of 3 seconds at a roller temperature of 130° C. The book cover was then removed from the rollers. This enabled a memory effect to be achieved in ply a) and dcd′): If the original form of the book cover was disturbed by opening, it closed again automatically (FIG. 5).

[0166] The book cover had a flat position of less than 5 mm, thus significantly better than the minimum value specified in ISO 18745-1.

Example 3: Passport Book Cover with PEBA and TPU Exterior Layer with Coloring and Lettering

[0167] Layer b) was printed in color over the whole area of one face. Printing was performed by means of toner printing on an MP C3003 model printer from the manufacturer Ricoh. In addition to the color-imparting whole-area printing, the lettering “Passport” was printed on layer b) which had already been printed in color.

[0168] Layer a), in the form of a layer sequence g-h) (consisting of a film g) and a film h), as described for film 2: 2-layer film with the layer sequence (g-h)), was arranged such that it was in contact with the printed side of the layer b), so that the print was visible through the transparent layer g-h).

[0169] A line, where the passport book cover was folded later, was marked on layer b). The material of layer b) was removed along these fold lines in an area with a width of 6 mm. For this, layer b) was placed in a Plator press and a 6 mm wide strip of material was stamped out along the fold line by means of a steel rule die.

[0170] Layers g-h) and b) were stacked according to FIG. 6) and fixed in their position by means of spot welding at the four sheet corners.

[0171] The stack of layers g-h) and b) was laminated on a Bürkle lamination press. The lamination plate that was in contact with layer g-h) was a lamination plate engraved over the whole area and having a non-stick coating. The engraving corresponded to a leather grain. The corresponding plate was supplied by the company 4-Plate.

[0172] Lamination Parameters:

[0173] Preheating of the press to 150° C.

[0174] Pressing for 5 minutes with a pressure of 20 N/cm.sup.2.

[0175] Cooling under a pressure of 150 N/cm.sup.2 until a temperature of 38° C. has been reached, and then opening the press.

[0176] After removal of the laminate, the side which had been in contact with the engraved plate exhibited a uniform leather grain which was also able to be perceived as leather. The color print remained undamaged after the lamination and appeared with good brilliance through the transparent exterior layer g-h). The adhesion of all layers was particularly good, and hence a non-destructive separation and reuse of the layers was not possible. The separation of the layers was tested by attempting to separate the individual layers from each other by hand. The layers could only be separated using appropriate tools (scissors, pliers), which resulted in damage to the layers.

[0177] A passport book cover was stamped out from the laminate in the desired size. The stamped-out book cover was then folded along the stamped-out cutout in the fold line. The folded side of the book cover was then clamped in a roll laminator in a width of 4 mm along the entire length of the book cover. The book cover was clamped for a period of 3 seconds at a roller temperature of 130° C. The book cover was then removed from the rollers. This enabled a memory effect to be achieved in ply g-h): If the original form of the book cover was altered or disturbed by opening the book cover, it closed again automatically. A slightly opened book cover is shown in FIG. 7 with the layers g-h) and d), as described above.

[0178] The book cover had a flat position of less than 5 mm, thus significantly better than the minimum value of <10 mm specified in ISO 18745-1, measurement being effected in accordance with method 9.6 of the standard.

Example 4: Passport Book Cover Made of PEBA and TPU with Coloring and Lettering and Integrated Chip Module and Antenna

[0179] In this example 4, a passport book cover having a structure as shown in FIG. 3 was manufactured, where, instead of the layer a), a layer g-h) consisting of the films g) and h) as described above was brought into contact with the layer b), the film h) pointing in the direction of the layer b).

[0180] For this, layer b) was printed in color over the whole area of one face. Printing was performed by means of toner printing on an MP C3003 model printer from the manufacturer Ricoh. In addition to the color-imparting whole-area printing, the lettering “Passport” was printed on layer b) which had already been printed in color.

[0181] The layer g-h) was arranged such that it was in contact with the printed side of the layer b), so that the print was visible through the transparent layer g-h).

[0182] An antenna made of copper wire was placed on a further (unprinted) layer b′) (see also FIG. 3, with layer a) having been replaced by layer g-h)). The wire had a diameter of 80 μm and was formed into the form of an antenna f) in accordance with the standard ISO 14443 for contactless data transfer. A chip module e), suitable for data storage and contactless data transfer in accordance with the standard ISO 14443, was contacted with the ends of the antenna.

[0183] A line, where the passport book cover was intended to be folded, was marked on each of layers b) and b′). The material of layer b) and b′) was removed along the fold line in a width of 6 mm. For this, layers b) and b′) were placed in a Plator press and a 6 mm wide strip of material was stamped out along the fold line by means of a steel rule die.

[0184] The layers were stacked according to FIG. 3 (with layer a) having been replaced by layer g-h)) and fixed in their position by means of spot welding at the four sheet corners.

[0185] The film stack according to FIG. 3 (with layer a) having been replaced by layer g-h)) was laminated on a Bürkle lamination press. The lamination plate that was in contact with layer g-h) was a lamination plate engraved over the whole area and having a non-stick coating. The engraving corresponded to a leather grain. The corresponding plate was supplied by the company 4-Plate.

[0186] Lamination Parameters:

[0187] Preheating of the press to 150° C.

[0188] Pressing for 5 minutes with a pressure of 20 N/cm.sup.2.

[0189] Cooling under a pressure of 150 N/cm.sup.2 until a temperature of 38° C. has been reached, and opening the press.

[0190] After removal of the laminate, the side which had been in contact with the engraved plate exhibited a uniform leather grain which was also able to be perceived as leather. The adhesion of all layers was particularly good, and hence a non-destructive separation and reuse of the layers was not possible. The separation of the layers was tested as described in example 1. The color print remained undamaged after the lamination and appeared with good brilliance through the transparent exterior layer g-h). The passport book cover further had a consistently homogeneous thickness distribution. Unevenness due to the antenna that had been incorporated by lamination and the chip module are taken up and compensated by the ply dcd′), as shown schematically in FIG. 4.

[0191] The laminates were stamped in the size of a passport book cover. The stamped-out book cover was then folded along the stamped-out cutout of the fold line. The folded side of the book cover was then clamped in a roll laminator in a width of 4 mm along the entire length of the book cover. The book cover was clamped for a period of 3 seconds at a roller temperature of 130° C. The book cover was then removed from the rollers. This enabled a memory effect to be achieved in ply g-h) and dcd′): If the original form of the book cover was altered by opening, it closed again automatically.

[0192] The book cover had a flat position of less than 5 mm, thus significantly better than the minimum value specified in ISO 18745-1.

[0193] Reference numerals of FIGS. 1 to 7: [0194] a) 150 μm TPU layer a) [0195] b) 250 μm thick synthetic paper (Teslin™ from PPG) printed over the whole area of one face. [0196] b′) 250 μm thick synthetic paper (Teslin™ from PPG), unprinted [0197] dcd′) film 1 as TPU three-layer film with the layer sequence dcd′), the layer c) taking the form of a foam layer. [0198] e) chip module [0199] f) antenna [0200] g) PEBA film [0201] h) TPU film [0202] V) compressed foam

[0203] FIG. 1 shows the layer sequence of example 1 before lamination.

[0204] FIG. 2 shows the folded laminate from example 1.

[0205] FIG. 3 shows the layer sequence of example 2 before lamination.

[0206] FIG. 4 shows the layer sequence of example 2 after lamination.

[0207] FIG. 5 shows the folded laminate from example 2.

[0208] FIG. 6 shows the layer sequence of example 3 before lamination.

[0209] FIG. 7 shows the folded laminate from example 3.