Layer structure for producing a hinge, in particular for producing multi-layered book covers
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.
1 . A hingeable layer structure comprising:
layers arranged in a sequence of a/b/d/c/d′/b′, wherein only one of layer d and layer d′ is present or both d and layer d′ are present in the layer structure, wherein
layer a is an outermost layer containing at least one thermoplastic elastomer comprising at least 50 wt % polyurethane, and layer a contacts layer b,
layers b and b′ contains at least one material selected from the group consisting of a polymer, a metal, a textile, a paper, a synthetic paper, or a combination thereof, and layer b either (i) contacts layer d if layer d is present, or (ii) contacts layer c if layer d is not present,
layer c contains at least one thermoplastic polyurethane which is formed at least in regions as a foam layer, and layer c either (i) contacts layer d′ if layer d′ is present, or (ii) contacts layer b′ if layer d′ is not present,
layer(s) d and/or d′ contain(s) at least one thermoplastic polyurethane having a hardness of ≥60 Shore A to ≤95 Shore D according to DIN ISO 7619-1, wherein layer d, if present, contacts layer c and layer d′, if present, contacts layer b′, and
layer b comprises a cutout of any desired form, wherein layer a, layer c, and layer(s) d and/or d′ extend across the cutout defining a hinge region.
2 . The layer structure of claim 1 , wherein layer d′ is present.
3 . The layer structure of claim 1 , wherein both layers d and d′ are present.
4 . The layer structure of claim 1 , layer b′ also comprising a cutout of any desired form, the cutout of layer b′ being aligned and overlapping in a thickness direction of the layer structure with the cutout of layer b.
5 . The layer structure of claim 1 , wherein the cutout in layer b has the form of a parallelogram having its major axis of running parallel to a line of symmetry of a length or a width of the layer structure.
6 . The layer structure of claim 1 , wherein the cutout in layer b comprises a dimension of ≥0.1 mm to ≤100 mm.
7 . The layer structure of claim 1 , wherein the cutout of layer of layer b is such that layer b is arranged in the form of at least two sections, with first and second sections flanking opposing lateral sides of the cutout.
8 . The layer structure of claim 4 , wherein the cutouts of layers b and b′ are such that each of layer b and layer b′ is arranged in the form of at least two sections, with first and second sections flanking opposing lateral sides of the corresponding cutout.
9 . The layer structure of claim 1 , wherein layers b and b′ each comprise the synthetic paper.
10 . The layer structure of claim 1 , wherein layer b comprises at least one dye and/or pigment.
11 . The layer structure of claim 10 , wherein layer b further comprises a print layer applied over at least a partial area.
12 . The layer structure as claimed in of claim 1 , wherein the 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.
13 . The layer structure of claim 1 , wherein layer a has a thickness in the range of ≥20 μm to ≤1000 μm.
14 . The layer structure of claim 1 , further comprising layer a′ and layer b″, wherein:
layer a′ contains at least one thermoplastic elastomer comprising at least 50 wt % polyurethane, and layer a contacts layer b′, and
layer b″ contains at least one material selected from the group consisting of a polymer, a metal, a textile, a paper, a synthetic paper, or a combination thereof, and layer b″ contacts layer a′.
15 . The layer structure of claim 1 , further including at least one component and/or at least one functional unit positioned on layer b′.
16 . The layer structure of claim 15 , wherein the at least one component and/or at least one functional unit is at least partially covered by the foam layer of layer c.
17 . The layer structure of claim 16 , wherein the at least one component and/or at least one functional unit is an electronic comprising a sensor, chip module, data storage media, battery, and/or illumination unit.
18 . A laminate comprising the layer structure of claim 1 .
19 . A multilayer book cover comprising the layer structure of claim 1 .
20 . A security or identification document comprising the multilayer book cover of claim 19 .