TRANSLUCENT METALLISED DESIGN SURFACE

Abstract

The invention relates to a multi-layered body comprising a transparent thermoplastic layer, a diffuser layer and a metal layer which, despite a decorative, structured visible surface, can transport information from a projection unit behind it with excellent sharpness and brightness. Corresponding elements can be used, for example, in Car-to-X communication.

Claims

1. A lighting unit, comprising the following elements in this sequence a transparent thermoplastic layer (300) having a visible side and a side facing away from the visible side, wherein the transparent layer (300) has a transmittance Ty of ≥10%, determined in accordance with DIN ISO 13468-2:2006 (D65, 10°), and has a 3-dimensionally structured surface on the side facing away from the visible side, a metal layer (200) directly on the transparent layer (300) on the side facing away from the visible side, wherein the metal layer (200) has a transmittance Ty of ≥4%, determined in accordance with DIN ISO 13468-2:2006 (D65, 10°), wherein the combined transmittance Ty of the metal layer (200) with the transparent layer (300), determined in accordance with DIN ISO 13468-2:2006 (D65, 10°), is at least 3.0%, a diffuser layer (100), which is at a distance of ≤5 mm from the metal layer and has a transmittance Ty of at least >50%, determined in accordance with DIN ISO 13468-2:2006 (D65, 10°), and a half-value angle of 10°≤<x≤50°, determined in accordance with DIN 5036:1978 (based on the light intensity), a light source (600), which conveys information and is at a distance from the diffuser layer of <80 cm.

2. The lighting unit as claimed in claim 1, wherein the metal layer (200) is vapor-deposited or applied to the transparent layer (300).

3. The lighting unit as claimed in claim 1, wherein the diffuser layer (100) is arranged directly on the metal layer (200).

4. The lighting unit as claimed in claim 1, wherein the diffuser layer (100) lies against the rear side of the metal layer (200).

5. The lighting unit as claimed in claim 1, wherein the light source (600) is a projector.

6. The lighting unit as claimed in claim 1, wherein the transmittance of the diffuser layer (100) is >80%, determined in accordance with DIN ISO 13468-2:2006.

7. The lighting unit as claimed in claim 1, wherein the 3-dimensionally structured surface has structural elements having a lateral extent of at least 1 mm, wherein the surface normals of these structural elements have an angular deviation of >0.5°, based on the surface normals of the adjoining structural elements, and wherein the height of these structural elements is in the range from 0.1 to 4 mm.

8. The lighting unit as claimed in claim 7, wherein the surface of the 3-dimensionally structured surface of the transparent thermoplastic layer (300) has more than 10 mutually distinguishable faces.

9. The lighting unit as claimed in claim 1, wherein the transparent thermoplastic layer (300) is based on aromatic polycarbonate.

10. The lighting unit as claimed in claim 1, wherein the transparent thermoplastic layer (300) on the visible side of the lighting unit has a maximum roughness of <0.1 μm, determined in accordance with DIN EN ISO 1302:2002-06.

11. The lighting unit as claimed in claim 1, wherein the diffuser layer (100) is applied directly to the metal layer (200).

12. The lighting unit as claimed in claim 1, wherein the transparent thermoplastic layer (300) has a neutral-gray color.

13. A component from the automobile exterior region, comprising a lighting unit as claimed in claim 1.

14. The component as claimed in claim 14, wherein the component is selected from the group consisting of a front panel, a side panel, a rear spoiler, a tailgate, and a subregion of these elements.

15. The component as claimed in claim 13, which is designed for car-to-X communication.

Description

[0129] The invention is elucidated below on the basis of an exemplary embodiment and with reference to FIG. 1.

[0130] FIG. 1: lighting unit according to the invention

[0131] FIG. 1 shows a lighting unit according to the invention having a multilayer body and a light source (600) which communicates information. The multilayer body comprises a transparent thermoplastic layer (300) having a visible side and a rear side opposite the visible side. A scratch-resistant coating (500) is applied to the visible side of the transparent thermoplastic layer (300).

[0132] A 3-dimensional structure is located on the rear side of the transparent thermoplastic layer (300). A metal layer (200), which follows the elevations and depressions of the three-dimensional structure, is applied directly to the rear side of the transparent thermoplastic layer (300). A diffuser layer (100) is arranged at a distance from the metal layer (200) with an air space (400) in between. Behind this is situated the light source (600), a projection element.

EXAMPLES

[0133] The examples described in table 1 were produced, measured and evaluated as follows:

[0134] For the tests, injection-molded sample plates with a rear three-dimensional surface structure and dimensions of 200 mm×150 mm×3 mm were produced from polycarbonate compositions. In order to obtain different transmittances, various mixing ratios of a clear transparent polycarbonate (Makrolon® AG2677/550396) and of a dark transparently colored polycarbonate (Makrolon AG2677/18F123MA03) from Covestro Deutschland AG, were set. The proportion of the dark-colored polycarbonate was between 5% and 75% by weight. Subsequently, aluminum layers having various transmittances Ty (1-25%) were applied to the sample plates under vacuum by means of a sputtering process. The transmittances were determined beforehand on reference samples (small glass plates) in accordance with DIN ISO 13468-2:2006 (D65, 10°). This gave the appropriate duration for the sputtering process for the various transmittances. Finally, the transmittances of the injection-molded sample plates with and without metallization layer were measured in accordance with DIN ISO 13468-2:2006 (D65, 10°) and visually assessed (% values in the table). The samples without metallization serve only as a reference. A diffuser film (Makrofol® LM 309 from Covestro Deutschland AG having a thickness of 300 μm, a transmittance according to DIN ISO 13468-2:2006 (D65, 10°) of 86% and a half-value angle of 20° according to DIN 5036:1978 (based on the light intensity)) was applied directly to the rear of the metallized plates and these were illuminated from the rear side, that is to say from the side facing away from the thermoplastic transparent layer, by a projector with a luminous power of 2000 lumen. The front side of the sample plates was exposed to direct daylight. The luminous power and color brilliance of the image projected through the sample plates were then evaluated in particular. The visual evaluation was divided into good (++), adequate (+) and poor (−−). The plates rated as good and adequate correspond to the embodiment according to the invention. The information conveyed by the projector was recognizable to a good to satisfactory extent.

TABLE-US-00001 TABLE 1 Proportion of the dark- Metal layer colored polycarbonate with 25% with 15% with 4% with 1% in the overall composition not present transmittance transmittance transmittance transmittance  5% by weight 75.49 24.74 (++) 14.24 (++) 3.23 (+) n/a (−) 10% by weight 64.98 20.38 (++) 14.11 (++) 2.58 (−) 0.44 (−)  20% by weight 51.48 18.83 (++) 7.74 (+) 1.81 (−) n/a (−) 30% by weight 43.51 15.00 (++) 8.28 (+) 1.41 (−) n/a (−) 40% by weight 36.82 11.54 (++) 6.61 (+) 1.15 (−) 0.26 (−)  50% by weight 30.73 11.19 (++) 5.05 (+) 1.42 (−) n/a (−) 75% by weight 9.08 2.28 (−) 1-82 (−) 0.39 (−) 0.06 (−)