Material having incorporated optical structures

Abstract

The invention relates to a material which is at least partially transparent and has structures incorporated in its inner volume following production of the material, said structures changing the volume with respect to its optical properties in relation to the non-structured volume. The material according to the invention is characterized in that the structure comprises modification bubbles which are formed in a uniform periodic arrangement in at least one plane in the volume.

Description

[0001] P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Advancement of Applied Research e. ​​V. / Device and method for the periodic volume structuring of clear liquid / ST / PM / 2024034828 / 03 December 2025

[0002] 1

[0003] Material with incorporated optical structures

[0004] The invention relates to a material that is at least partially transparent and that has structures introduced into its internal volume after material production, which modify the volume with respect to its optical properties compared to the unstructured volume. The invention also relates to a vehicle with a component, or a component for a vehicle, that incorporates such a material.

[0005] Such materials, which are structured using laser beams, for example, are fundamentally known from the prior art. A corresponding material is described in DE 10 2022 130 159 A1. Furthermore, US 2017 / 0 355 215 A1 describes a similar material whose volume is marked or modified using a laser beam.

[0006] WO 2015 / 044168 A1 describes in its introductory section the prior art of transparent materials made of glass or glass-ceramics in which microcracks are created within the material using a laser beam. These microcracks scatter the light, and with a suitable arrangement of microcracks within the material's volume, three-dimensional images can be generated. WO 2015 / 044168 A1 further develops this fundamentally known method by using a laser beam to non-destructively modify the optical properties of the material in order to reduce transmission or remission and increase absorption coefficients. This allows the material properties to be adjusted to achieve an image quality that goes beyond simply generating microcracks.P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Promotion of Applied Research e. ​​V / Device and method for periodic volume structuring of Klarlaok / ST / PM / 2024034828 / 03 December 2025.

[0007] 2

[0008] For further information on the state of the art, reference can also be made to DE 10 2008 021 658 A1. This describes volume modulation using a laser in a emitting body surrounding a light-emitting diode. This allows a type of diffuser to be created in the transparent part of the LED housing, thereby increasing the LED's luminous efficacy.

[0009] The object of the present invention is to provide an improved material according to the preamble of claim 1, which can be easily varied with respect to its optical appearance recognizable to an observer, such as color.

[0010] According to the invention, this problem is solved by a material having the features of claim 1, and in particular those of the characterizing part of claim 1. Advantageous embodiments of the material according to the invention are set forth in the dependent claims. Furthermore, a vehicle with a component or a component for a vehicle according to claim 12 solves the problem.

[0011] The material according to the invention is provided within its volume after production with structures which alter the optical properties, and in particular the transmission and / or reflection or remission, of the volume in the region of the structures, in contrast to the unstructured volume. According to the invention, the structures are designed as modification bubbles which are formed in a uniform periodic arrangement in at least one plane within the volume.

[0012] Unlike attempts to create three-dimensional images in glass or glass-ceramics, the material according to the invention implements a structure of modification bubbles, which are formed in a uniform periodic arrangement within the volume. The modification bubbles are arranged in one plane and extend into the third, perpendicular plane. P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Advancement of Applied Research e. ​​V. / Device and method for periodic volume structuring of clear liquid / ST / PM / 2024034828 / 03 December 2025

[0013] 3

[0014] The modification bubbles have a very small thickness in this third dimension. In particular, they form the structure of an optical grating, which alters the transmission and reflection behavior of light. Depending on the geometric arrangement and spacing of the modification bubbles within the structure, various optical properties can be achieved, resulting in a very high degree of flexibility in optical design. With a single layer, which can easily be incorporated even into very thin transparent materials such as paint layers, various shades of gray from white to black, with all conceivable intermediate shades, can be created.With a different arrangement of the modification bubbles, an iridescent optical effect can be achieved, either additionally or alternatively. In this effect, the structured area of ​​the volume appears in different colors, which change depending on the viewing angle. Typically, this results in a rainbow-colored image. This is possible on at least one plane within the volume, meaning that two-dimensional images such as brand logos, decorations, ornaments, or the like can be incorporated into the material via the modification bubbles.

[0015] A further highly advantageous embodiment of the material according to the invention can further provide that the structure comprises a three-dimensional point grid of modification bubbles extending from a plane. According to an advantageous further development, the point grid can lie in at least three parallel planes, each of which comprises a point matrix. The individual planes can be arranged at uniform intervals from one another or vary in their spacing. For example, it is possible to form two planes very close to each other and to position at least one further plane at a significantly greater distance from them.This allows for the implementation of various color effects in succession on different levels, resulting in a high degree of variability with regard to the white, black and P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Promotion of Applied Research e V / Device and method for periodic volume structuring of clear liquid / ST / PM / 2024034828 / 03 December 2025.

[0016] 4

[0017] This leads to a combination of gray tones on the one hand and iridescent colors on the other. In particular, these can be combined with each other in different layers within a given viewing direction. For example, a dot grid could be created in a lower layer, resulting in a light color perception, and a dot grid in an upper layer, resulting in an iridescent color perception, thus, for instance, "underlining" an iridescent logo with a light color.

[0018] According to a particularly advantageous embodiment, the modification bubbles of the respective dot matrix are formed as an arrangement of parallel or intersecting lines. A line, in the sense of the present invention, means that the spacing of the modification bubbles within the line, or in the direction of the line, is smaller than the spacing perpendicular to it. This allows a predetermined optical grating to be efficiently implemented using the line structure.

[0019] According to a highly advantageous further development, the distance between the modification bubbles in one direction within the plane can be on the order of the wavelength of visible light, i.e., approximately between 400 and 780 nm. A similar spacing of the modification bubbles within the line, if the modification bubbles are arranged in lines, then creates the iridescent color effect mentioned above, which is perceptible to the human eye in different colors depending on the viewing direction and shines in the colors of the rainbow. When the material is moved, the position of the individual colors within the structure changes relative to the eye.

[0020] The structure itself can be generated within the volume of the material in any desired manner, particularly with the aid of radiation, such as plasma or ion radiation. It is especially preferred that it be generated using a focused laser beam, for example, an ultrashort pulse laser. Preferably, the entire structure consists exclusively of P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Advancement of Applied Research e. ​​V. / Device and method for the periodic volume structuring of clear lacquer / ST / PM / 2024034828 / 03 December 2025

[0021] 5 the modification bubbles, thus omitting any other inclusions or the like.

[0022] According to a highly advantageous embodiment, the modification bubbles can have a droplet-shaped form with a diameter of 0.1 to 10 pm. Ideally, the droplet diameter is approximately 2 to 8 pm. The at least one plane in which this structure is arranged can be positioned at a predetermined angle to a visible material surface. The angle can preferably be between 0°, i.e., the plane running parallel to the visible material surface, and up to 90°. Ideal angles lie between 0° and up to 60°. This enhances the optical effect of color and, in particular, iridescent light from certain viewing directions. If the visible surface is three-dimensionally curved, the predetermined angle to a flat compensating surface can be determined by this surface.When several layers are arranged on top of each other, they can also be arranged at different predetermined angles to the visible material surface in order to create different color effects when viewing the material obliquely than when viewing the surface of the material perpendicularly.

[0023] As can already be seen from the preferred dimensions of the modification bubbles described above, the structure in the material according to the invention can be made extremely small. Several parallel planes can therefore also be integrated into an at least partially transparent surface coating. Such an at least partially transparent surface coating can be realized, in particular, on the basis of polymer materials.

[0024] According to a highly advantageous embodiment of the material according to the invention, the surface coating can be designed as a partially transparent lacquer layer, in particular as a clear lacquer layer. The material in the form of a P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Advancement of Applied Research e.V. / Device and method for the periodic volume structuring of clear lacquer / ST / PM / 2024034828 / 03 December 2025

[0025] 6. Such a clear coat layer can therefore be provided with the appropriate structures after production, preferably via a laser, in order to subsequently provide a clear coat layer with a certain color, for example, to introduce grey, white or black lettering, brand logos and / or iridescent brand logos, fonts or other optical representations into the already applied clear coat.

[0026] A preferred application here is in the field of automotive engineering. For example, a vehicle may be equipped with at least one component, or a component may be implemented as an add-on part for a vehicle, wherein the component has at least a partially transparent surface coating, which is implemented as a material according to one of the configurations described above. For example, a structure may be subsequently introduced into the paintwork of a vehicle or an add-on part for a vehicle, such as a rim or the like, in order to create, for example, iridescent brand logos in the clear coat of a rim, or the like.

[0027] Further advantageous embodiments will also become clear from the following exemplary embodiment, which is described with reference to the figures.

[0028] Accordingly, the following figures show:

[0029] Fig. 1 shows a cross-section through a substrate with a transparent lacquer layer and a structure inside the lacquer layer;

[0030] Fig. 2 is a top view of the representation according to Fig. 1;

[0031] Fig. 3 shows a cross-section through a substrate with a transparent lacquer layer and an alternative structural configuration in P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Advancement of Applied Research e. ​​V. / Device and method for periodic volume structuring of clear lacquer / ST / PM / 2024034828 / 03 December 2025

[0032] 7

[0033] interior of the paint layer; and

[0034] Fig. 4 is a photographic illustration of a material according to the invention on a section of a rim.

[0035] Figure 1 shows a material 1 that is at least partially transparent, here in the form of a transparent surface coating, in particular a clear lacquer. This clear lacquer 1 is applied to a substrate designated 2. Within the thickness of the clear lacquer 1, structures designated 3 are arranged in three planes, one behind the other, extending from a visible surface 4 of the clear lacquer 1. Each of these planes contains a dot matrix or a line matrix, the lines being designated by reference numeral 6 in accordance with the invention.

[0036] In the top view shown in Figure 2, it can be seen that the individual lines 6, each formed from a series of modification bubbles 5 (described in more detail in Figures 3 and 4), create a regular rectangular grid. This allows the optical properties, particularly the transmission and reflection within the clear coat 1, to be modified accordingly. For example, structures 3, such as an iridescent brand logo, can be subsequently introduced into an already applied clear coat layer using a laser.

[0037] The modification bubbles 5 themselves are droplet-shaped. Their diameter ranges from 0.1 to 10 pm, typically from approximately 2 to 8 m. The modification bubbles 5 alter the refractive index of the clear coat 1 used. According to current findings, this is presumably due to a reorganization / rapid solidification of the molten clear coat 1, as well as a local change in chemical composition caused by irradiation. P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Advancement of Applied Research e. ​​V. / Device and method for the periodic volume structuring of clear coat / ST / PM / 2024034828 / 03 December 2025

[0038] 8

[0039] The lines 6 are formed by a series of modification bubbles 5, which is indicated here by the dotted representation of the lines 6. To achieve an iridescent color effect, the distance between the modification bubbles 5 of each individual line 6 is on the order of 400 to 780 nm. The distance x between the individual lines 6 is, for example, more than 30 m. A group of parallel lines 6, or, as shown in Figure 2, of intersecting parallel lines 6, then forms an optical grating as structure 3. Such an optical grating, with a spacing of the modification bubbles 5 in each of the lines 6 on the order of visible light (approx. 400 to 780 nm), produces the iridescent color effect.If the spacing of the modification bubbles 5 within line 6 is increased beyond the order of magnitude of visible light (or decreased below it, although this is more difficult to implement), black, white, and shades of gray can be created. This already provides a high degree of design flexibility.

[0040] If different planes are provided with different grids, different distances can be chosen between the modification bubbles 5 in line 6, for the distance x between the lines 6, and for the distance between the planes themselves, further increasing the design possibilities. In addition, the angles of the individual planes to each other and to the visible surface 4 can now also be changed. This is not apparent in Figure 3, which is otherwise analogous to Figure 1.

[0041] Finally, Figure 4 shows a photograph of a section of a rim 7 for a vehicle not depicted in its entirety. The rim 7 is coated with a clear coat, which is at least partially transparent material 1. Structures 3 are incorporated into this clear coat in at least one plane, particularly parallel to the visible surface 4 of the clear coat 1. These structures form the "Maybach" brand logo (according to P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Advancement of Applied Research e.V. / Device and method for periodic volume structuring of clear coat / ST / PM / 2024034828 / 03 December 2025).

[0042] 9 of a protected trademark of one of the co-applicants). The entire optical effect, which makes the trademark logo visible as structure 3 within the clear coat, is based on modification bubbles 5, which are formed in a uniform periodic arrangement within the volume of the clear coat. In the implementation, the distances between the modification bubbles 5 within the line were approximately 550-620 nm and the distances x of the lines 6 were several tens of meters, so that the trademark logo is visible in iridescent colors, which can only be discerned in the grayscale representation of Figure 6 by different shades of brightness.

Claims

P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Advancement of Applied Research e. ​​V. / Device and method for the periodic volume structuring of clear liquid / ST / PM / 2024034828 / 03 December 2025 10 Patent claims 1. Material (1) which is at least partially transparent and which has structures (3) introduced into its internal volume after the material production, which modify the volume with respect to its optical properties compared to the unstructured volume, characterized in that the structure (3) comprises modification bubbles (5) which are formed in a uniform periodic arrangement in at least one plane in the volume.

2. Material (1) according to claim 1 , characterized in that the structure (3) comprises a three-dimensional point grid of modification bubbles (5) originating from a plane.

3. Material (1) according to claim 2 characterized in that the three-dimensional point grid comprises at least three point matrices lying in parallel planes.

4. Material (1) according to claim 3, characterized in that the modification bubbles (5) of the respective point matrix have an arrangement of parallel or intersecting lines.

5. Material (1) according to one of claims 1 to 4, characterized in that the distance between the modification bubbles (5) is in one direction P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Advancement of Applied Research e. ​​V. / Device and method for the periodic volume structuring of clear liquid / ST / PM / 2024034828 / 03 December 2025 1 1 within the plane lies on the order of the wavelength of visible light.

6. Material (1) according to one of claims 1 to 5, characterized in that the structure (3) is produced by means of a focused laser beam.

7. Material (1) according to one of claims 1 to 6, characterized in that the modification bubbles (5) have a droplet-shaped configuration with a They have diameters ranging from 0.1 to 10 m.

8. Material (1) according to one of claims 1 to 7, characterized in that the at least one plane is arranged at a predetermined angle to a visible material surface (4).

9. Material (1) according to claim 8, characterized in that several planes are arranged at different predetermined angles to the visible side material surface (4) is arranged.

10. Material (1) according to any one of claims 1 to 9 characterized by its design as at least partially transparent Surface coating (1).

11. Material (1) according to claim 10 characterized by its design as an at least partially transparent lacquer layer (1), P 2023-02404WO / 2023PF02404 / Mercedes-Benz Group AG, Fraunhofer Society for the Advancement of Applied Research e. ​​V. / Device and method for the periodic volume structuring of clear liquid / ST / PM / 2024034828 / 03 December 2025 12 especially as a clear coat (1).

12. Material (1) according to one of claims 1 to 11 , characterized in that the structures (3) are formed exclusively by the modification bubbles (5).

13. Vehicle comprising at least one component or component for a vehicle, wherein the component has an at least partially transparent surface coating (1) which is designed as material (1) according to any one of claims 1 to 12.

Images