Basf Se Corporation

Basf Schweiz Ag

Nikolay A Grigorenko

Garo Khanarian

Oliver Seeger

Andreas Mühlebach

Michelle Richert

Ralf Knischka

Herve Dietsch

Andreas Gernandt

Roland Fleury

Rui Zhang

Olivier Enger

Frank Knocke

Andre Oswald

Andreas Muehlebach

Holger Leybach

The present invention relates to security elements, comprising (a) a substrate, (b) on at least part of the substrate surface a metal layer, (c) optionally on at least part of the metal layer a dielectric layer, (d) on at least part of the metal layer, or the dielectric layer, a layer obtained by overcoating the metal layer, or the dielectric layer with a composition, comprising (i) silver nanoparticles, (ii) a solvent, (iii) (surface) stabilizing agent(s) and (iv) optionally a binder, and (e) a protective layer on top of layer (d). The maximum absorption wavelength of the silver nanoparticles in layer (d) is controlled by the amount of (surface) stabilizing agent(s) and optionally binder relative to the amount of silver nanoparticles to be preferably in the range of 700 to 1600 nm.

Security element

The present invention relates to compositions, comprising silver nanoplatelets, wherein the mean diameter of the silver nanoplatelets, present in the composition, is in the range of 20 to 70 nm with standard deviation being less than 50% and the mean thickness of the silver nanoplatelets, present in the composition, is in the range of 5 to 30 nm with standard deviation being less than 50%, wherein the mean aspect ratio of the silver nanoplatelets is higher than 1.5, a process for its production, printing inks containing the compositions and their use in security products. The highest wavelength absorption maximum of the population of all silver nanoplatelets in the composition being within the range of 450 to 550 nm. A coating, comprising the composition, shows a red, or magenta color in transmission and a greenish-metallic color in reflection.

Compositions, comprising silver nanoplatelets

The present invention relates to security, or decorative elements, comprising a transparent, or translucent substrate, which may contain indicia or other visible features in or on its surface, and on at least part of the substrate surface, a first layer, comprising transition metal particles having an average diameter of from 5 nm to 500 nm and a binder, on at least part of the first layer a second layer, comprising an organic material and having a refractive index of from 1.2 to 2.3 and having a thickness of from 20 to 1000 nm, wherein the transition metal is silver, copper, gold and palladium, wherein the weight ratio of transition metal particles to binder in the first layer is in the range from 20:1 to 1:2 in case the binder is a polymeric binder, or wherein the weight ratio of transition metal particles to binder in the first layer is in the range from 5:1 to 1:15 in case the binder is an UV curable binder. The security or decorative element show a certain color in transmission and a different color in reflection and a color flop on the coating side. The color in reflection and the color flop of the security or decorative elements are controlled by adjusting the refractive index and thickness of the second layer.

The present invention relates to a process for the preparation of thin silver nano-particles containing layers, which are produced directly on a substrate as part of a coating or printing process. The layers can show different colours in transmittance and reflectance. The invention further relates to decorative and security elements. When the layers are applied over a security element, such as a hologram, the obtained products may show different colours in reflection and transmission, an extremely bright optically variable image (OVD image). Depending on the thickness of the layer a more or less intensive metallic aspect appears.

Process for the preparation of metallic nano-particle layers and their use for decorative or security elements

The invention relates to a process for producing a patterned transparent conductive film comprising areas with lower conductivity and areas with higher conductivity, comprising following steps: (a) applying an ink comprising electrically conductive nanoobjects with or without a binder on a substrate, forming a first layer, wherein the amount of conductive nanoobjects is such that the first layer has a low conductivity after drying; (b) drying of the first layer; (c) applying an ink comprising a metallo-organic complex in a predetermined pattern on the first layer; (d) decomposing of the ink applied in step (c), thereby forming a pattern having a higher conductivity on the first layer. The invention further relates to a transparent conductive film, comprising areas with lower conductivity and areas with higher conductivity, wherein the areas with higher conductivity and the areas with lower conductivity comprise nanoobjects and in the areas with higher conductivity, the nanoobjects are fused by metal generated by decomposition of a metallo-organic complex.

Process for producing a patterned transparent conductive film and a transparent conductive film

The present invention relates to complex security elements based on liquid crystal coatings which are subsequently coated with specific metallic nano-shaped metal particles, a method for their manufacture, in particular on a glass, paper or on a plastic substrate and a security product obtainable using the security element. The security element may contain additionally an embossed surface relief microstructure, especially an optically variable image (an optically variable device, OVD), such as a hologram. A further aspect of the invention is the use of such a security element for the prevention of counterfeit or reproduction of a document of value.

Security elements and method for their manufacture

The present invention relates to the use of coating compositions, comprising shaped transition metal, especially silver, particles and a binder, wherein the ratio of pigment to binder is preferably such that the resulting coating shows an angle dependent color change, for the production of security elements and holograms. When the coating compositions of the present invention are used in coating a hologram the obtained products show a an angle dependent color change (flip/flop effect), different colors in reflection and transmission, an extremely bright OVD image and extremely strong rainbow effect, high purity and contrast.

Coating compositions for security elements and holograms

The present invention relates to complex security elements based on recording materials for optical elements with refractive index modulation, in particular, holograms, which are subsequently coated with specific metallic nano-shaped metal particles, a method for their manufacture, in particular on a paper or on a plastic substrate and a security product obtainable using the security element. A further aspect of the invention is the use of such a security element for the prevention of counterfeit or reproduction of a document of value.

The present invention relates to a coating composition, comprising shaped transition metal, especially silver, particles and a binder, wherein the ratio of pigment to binder is such that the resulting coating shows an angle dependent color change. When the coating compositions of the present invention are used in coating a hologram the obtained products show a an angle dependent color change (flip/flop effect), different colors in reflection and transmission, an extremely bright OVD image and extremely strong rainbow effect, high purity and contrast.

The instant invention relates to shaped transition metal particles, in particular in the form of a dispersion in an aqueous and/or organic medium, the manufacture thereof and their use as an infrared (IR) absorbing agent, an IR curing agent for coatings, an additive in conductive formulations, an antimicrobial agent or for sensoring organic and/or inorganic compounds. Further, the invention relates to dispersions comprising said shaped particles and an aqueous and/or organic medium, such as a thermoplastic or crosslinkable polymer, as well as to antimicrobial compositions and products.

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Basel, Switzerland

Nikolay A Grigorenko