METHOD FOR PRODUCING EFFECT PIGMENTS

Abstract

A method for manufacturing platelet-shaped effect pigments includes the steps of a) providing a carrier substrate; b) applying aqueous washing ink droplets to the carrier substrate in first regions forming a first motif; c) applying a reflective coating to the carrier substrate such that a reflective coating is deposited on the carrier substrate in the form of a regular contiguous grid in second regions forming a second motif outside the first regions forming the first motif, wherein the first regions form the first motif and have the washing ink droplets form regular islands within the regular contiguous grid, and a reflective coating is deposited above the washing ink droplets in the first regions forming the first motif; and d) removing the washing ink droplets in the first regions together with the reflective coating present thereon and isolating the removed reflective coating in the form of platelet-shaped effect pigments.

Claims

1-10. (canceled)

11. A method for manufacturing platelet-shaped effect pigments, comprising the following steps of: a) providing a carrier substrate; b) applying by printing technology in a controlled manner aqueous washing ink droplets to the carrier substrate in first regions forming a first motif; c) applying a reflective coating to the carrier substrate, so that in second regions forming a second motif outside the first regions forming a first motif, reflective coating is deposited on the carrier substrate in the form of a regular, contiguous grid, wherein the first regions forming a first motif and having the washing ink droplets form regular islands within the regular, contiguous grid; in the first regions forming a first motif, reflective coating is deposited above the washing ink droplets; d) removing the washing ink droplets in the first regions together with the reflective coating present thereon and isolating the removed reflective coating in the form of platelet-shaped effect pigments, wherein the remaining carrier substrate is constituted such that it has a reflective coating in the form of a regular, contiguous grid only in the second regions forming a second motif.

12. The method according to claim 11, wherein step b), namely applying by printing technology in a controlled manner aqueous washing ink droplets to the carrier substrate in first regions forming a first motif, takes place by means of a printing cylinder having a cell grid or a printing plate having a cell grid, wherein the geometry of the platelet-shaped effect pigments produced in the method is determined by a suitable choice of the parameters of cell arrangement, areal cell geometry, cell depth and web width.

13. The method according to claim 12, wherein the printing cylinder or the printing plate has a plurality of different cell grid regions, wherein the cell grid regions differ from one another in at least one of the parameters of cell arrangement, areal cell geometry, cell depth and web width, so that the platelet-shaped effect pigments produced in the method have a plurality of platelet-shaped effect pigments with different geometries corresponding to the plurality of different cell grid regions.

14. The method according to claim 11, wherein the aqueous washing ink droplets in step b) are based on an aqueous washing ink having a binding agent, wherein the binding agent preferably is a polymer and the polymer is particularly preferably chosen from the group composed of hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, polyvinyl alcohol, in particular with a low molecular weight and with a medium degree of hydrolysis, polyvinyl pyrrolidone, polyethylene glycol and casein.

15. The method according to claim 11, wherein between the steps b) and c) a drying of the aqueous washing ink droplets applied to the carrier substrate is carried out.

16. The method according to claim 11, wherein in step a) a foil is provided as the carrier substrate.

17. The method according to claim 11, wherein the reflective coating applied in step c), and thus each of the platelet-shaped effect pigments isolated in step d), is a metallization, preferably a metallization chosen from the group composed of aluminum, stainless steel, nichrome, gold, silver, platinum and copper.

18. The method according to claim 11, wherein the reflective coating applied in step c), and thus each of the platelet-shaped effect pigments isolated in step d), has a multilayer arrangement, preferably a multilayer arrangement with the layer sequence: semi-transparent absorber layer/dielectric spacer layer/reflective layer; or semitransparent absorber layer/dielectric spacer layer/reflective layer/dielectric spacer layer/semitransparent absorber layer.

19. The method according to claim 18, wherein the reflective coating applied in step c), and thus each of the platelet-shaped effect pigments isolated in step d), has a multilayer arrangement with the layer sequence semitransparent absorber layer/dielectric spacer layer/reflective layer, namely a Cr/SiO.sub.2/Al multilayer arrangement.

20. The method according to claim 18, wherein the reflective coating applied in step c), and thus each of the platelet-shaped effect pigments isolated in step d), has a multilayer arrangement with the layer sequence semitransparent absorber layer/dielectric spacer layer/reflective layer/dielectric spacer layer/semitransparent absorber layer, namely a Cr/SiO.sub.2/Al/SiO.sub.2/Cr multilayer arrangement or an Al/SiO.sub.2/Al/SiO.sub.2/Al multilayer arrangement, wherein in the case of the Al/SiO.sub.2/Al/SiO.sub.2/Al multilayer arrangement, the central Al layer has a greater layer thickness than each of the two terminal Al layers.

Description

[0036] Further embodiment examples as well as advantages of the invention will be explained hereinafter with reference to the figures, in whose representation a rendition that is true to scale and to proportion has been dispensed with in order to increase the clearness.

[0037] There are shown:

[0038] FIGS. 1-4 a manufacture of platelet-shaped effect pigments according to the invention;

[0039] FIG. 5 a grid of reflective coating remaining after a first manufacture according to the invention, magnified 25 times;

[0040] FIG. 6 the grid of reflective coating remaining after a first manufacture according to the invention, magnified 100 times;

[0041] FIG. 7 a grid of reflective coating remaining after a second manufacture according to the invention, magnified 25 times; and

[0042] FIG. 8 the grid of reflective coating remaining after the second manufacture according to the invention, magnified 100 times.

[0043] FIGS. 1 to 4 each illustrate, in cross-sectional views, the manufacture according to the invention of platelet-shaped effect pigments 5 in accordance with an exemplary embodiment.

[0044] According to FIG. 1, a carrier substrate 1 is provided, in the example a polyethylene terephthalate (PET) foil.

[0045] According to FIG. 2, the controlled application by printing technology of aqueous washing ink droplets 2 takes place on the carrier substrate 1 in first regions 3 forming a first motif In second regions 4 forming a second motif, no washing ink droplets 2 are applied.

[0046] According to FIG. 3, the application of a reflective coating (5, 6), e.g. a metallization or an interference layer structure, to the carrier substrate 1 takes place, so that in second regions 4 forming a second motif outside the first regions 3 forming a first motif, a reflective coating 6 is deposited on the carrier substrate 1 in the form of a regular, contiguous grid, wherein the regions 3 forming a first motif and having the washing ink droplets 2 form regular islands within the regular, contiguous grid. In the first regions 3 forming a first motif, reflective coating 5 is deposited above the washing ink droplets 2.

[0047] Subsequently, the removal of the washing ink droplets 2 takes place in the first regions 3 together with the reflective coating 5 present thereon by washing out with a suitable washing solution (see product “B” in FIG. 4). The platelet-shaped effect pigments 5 are subsequently isolated.

[0048] What remains is the product “A” shown in FIG. 4, namely the carrier substrate 1, which has a reflective coating 6 in the form of a regular, contiguous grid only in the second regions 4 forming a second motif

[0049] FIG. 5 shows the image of a remaining grid “A” of reflective coating 6, magnified 25 times. The manufacture took place employing a gravure printing plate having cells. The washing ink used for the application by printing technology of aqueous washing ink droplets was based on the binding agent polyvinyl pyrrolidone. After the vapor deposition of a metallization, in the example an Al layer, the step of washing out with an aqueous washing solution took place. A transparent, conductive metallization in the form of a regular, contiguous grid remained on the carrier substrate, in the example a polyethylene terephthalate (PET) foil. In FIG. 5 the targeted guiding of the metal lines can be recognized, which reflect the webs of the gravure printing plate employed in the manufacture, and the regular islands, which reflect the platelet-shaped effect pigments produced (see reference number 5 in FIG. 4).

[0050] FIG. 6 shows the image of the remaining grid “A” of reflective coating 6 enlarged 100 times in plan view.

[0051] FIG. 7 shows a grid “A” of reflective coating 6 that remains after a second manufacture according to the invention, magnified 25 times. Platelet-shaped effect pigments (see reference number 5 in FIG. 4) were obtained substantially according to the same production method as above with reference to FIGS. 5 and 6, wherein this time a different gravure printing plate having a larger web width was used for the application by printing technology of aqueous washing ink droplets 2. In FIG. 7 the targeted guiding of the metal lines can be recognized, which reflect the webs of the gravure printing plate employed in the manufacture, and the regular islands, which reflect the platelet-shaped effect pigments produced (see reference number 5 in FIG. 4).

[0052] FIG. 8 shows the image of the grid “A” of reflective coating 6 that remains after the second manufacture according to the invention, magnified 100 times in plan view.