Layer structure with modified structure, and production thereof
The invention relates to a layer structure containing: (A) a first transparent radiation-engravable layer (A) with a first surface a 1 ) and a second surface a 2 ) which runs substantially parallel to the surface a 1 ), said first layer (A) having a colorful or black part-engraving, said engraving being generated by means of nonionizing electromagnetic radiation (E), on the first surface a 1 ) which forms a first outer surface of the layer structure; (B) optionally an additional transparent radiation-engravable layer (B) with a first surface b 1 ) facing towards the first layer (A) and another surface b 2 ) facing away from the first layer (A) and running substantially parallel to the surface b 1 ); and (C) optionally at least one additional transparent plastic layer (C), wherein the additional layer (C) is selectively provided in one of a group of options consisting of: on the face of the first surface a 1 ) of the layer (A), on the face of the additional surface b 2 ) of the additional layer (B), between the two layers (A) and (B), or, in the event of additional layers (C), a combination of at least two of said options, and an image of the colorful or black part-engraving is located on the surface of the layer structure in the form of a nontransparent structural modification forming an additional outer surface of the layer structure and lying opposite the first surface a 1 ). The invention likewise relates to the production of the layer structure as well as to a security document containing the layer structure according to the invention.
1. A layer construction comprising:
(A) a first transparent radiation-engravable layer (A) having a first surface a 1 ), and a second surface a 2 ) that runs parallel to the first surface a 1 ), wherein the first layer (A) on its first surface a 1 ) which forms a first outer face of the layer construction has a colored or black engraving over a part of the area that has been produced by means of nonionizing electromagnetic radiation (E);
(B) a further transparent radiation-engravable layer (B) having a first surface b 1 ) facing in a direction of the first layer (A) and a further surface b 2 ) facing in a direction away from the first layer (A) and parallel to the first surface b 1 );
(C) at least one additional transparent polymer layer (C), wherein arrangement of an additional layer (C) is selected from the group consisting of: on a side of a further surface b 2 ) of the first layer (B), between the two layers (A) and (B), or a combination of at least two of these in the case of multiple further layers (C),
wherein an image of the colored or black engraving over part of the area is present in the form of a nontransparent structural alteration at the surface of the layer construction forming a further outer face of the layer construction and is opposite the first surface a 1 ), and
wherein the nontransparent structural alteration at the surface of the layer construction has a cloudy or milky appearance with a haze of ≥80%.
2. The layer construction as claimed in claim 1 , wherein layer (B) at sites with the altered structure has a layer thickness at least 0.001 mm thicker than at the sites without altered structure.
3. The layer construction as claimed in claim 1 , wherein at least one of layers (A), (B) and (C) has one of the following properties:
I. a layer thickness within a range from 10 μm to 10 000 μm;
II. a radiation transmittance of ≥2% to ≤99.95%, for the chosen radiation, determined by the UV-VIS-NIR-MIR method to DIN EN ISO/IEC 17025.
4. The layer construction as claimed in claim 1 , wherein at least layer (A), includes a thermoplastic selected from the group consisting of polymers of ethylenically unsaturated monomers, polycondensates of bifunctional reactive compounds, and polyaddition products of bifunctional reactive compounds, and combinations of at least two of these.
5. The layer construction as claimed in claim 1 , wherein layer (A), comprises at least one additive having an absorption maximum in the wavelength range of focused nonionizing electromagnetic radiation, or wherein layer (A), is coated with at least one additive in a coating composition having an absorption maximum in the wavelength range of the focused nonionizing electromagnetic radiation.