A security system, such as a banknote, comprises: i) a substrate, ii) a first ink, which is applied on at least a part of at least one surface of the substrate, wherein the first ink includes at least one IR luminescent dye and/or at least one IR luminescent pigment, and iii) a second non-luminescent ink, which is applied on at least a part of at least one surface of the substrate onto which the first ink is/are applied, wherein the second ink includes at least one non-luminescent IR absorbing pigment and/or a least one non-luminescent IR absorbing dye, wherein the first ink and the second ink at least partially overlap on the at least one surface of the substrate, wherein the second ink is applied in the overlapping area onto the first ink, and wherein the emission spectrum of the first ink and the absorption spectrum of the second ink at least partially overlap.

Provided is an oil-based inkjet ink containing a pigment and a fatty acid ester-based solvent represented by general formula (1) shown below and having at least 18 but not more than 29 carbon atoms per molecule. In general formula (1), R.sup.1 represents an alkyl group of 5 or more carbon atoms, R.sup.2 represents an alkyl group of 6 or more carbon atoms, and at least one of R.sup.1 and R.sup.2 is a branched alkyl group of 9 or more carbon atoms having a side chain of 4 or more carbon atoms. ##STR00001##

Provided is an oil-based inkjet ink containing a pigment and a fatty acid ester-based solvent represented by general formula (1) shown below and having at least 18 but not more than 29 carbon atoms per molecule. In general formula (1), R.sup.1 represents an alkyl group of 5 or more carbon atoms, R.sup.2 represents an alkyl group of 6 or more carbon atoms, and at least one of R.sup.1 and R.sup.2 is a branched alkyl group of 9 or more carbon atoms having a side chain of 4 or more carbon atoms. ##STR00001##

A modified pigment for radiation curable gravure ink, comprising a pigment and inorganic oxide nanoparticles coated on the surface of the pigment, wherein the DBP oil absorption is 150 ml/100 g-250 ml/100 g, the particle size is 0.01 μm-1 μm, and the pH value is 4.5-10.

A modified pigment for radiation curable gravure ink, comprising a pigment and inorganic oxide nanoparticles coated on the surface of the pigment, wherein the DBP oil absorption is 150 ml/100 g-250 ml/100 g, the particle size is 0.01 μm-1 μm, and the pH value is 4.5-10.

The present invention relates to metal oxide nanoparticles, a method for their production, a coating, or printing composition, comprising the metal oxide nanoparticles and the use of the composition for coating of surface relief micro- and nanostructures (e.g. holograms), manufacturing of optical waveguides, solar panels, light outcoupling layers for display and lighting devices and anti-reflection coatings. Holograms are bright and visible from any angle, when coated, or printed with the composition, comprising the metal oxide nanoparticles.

The present invention relates to metal oxide nanoparticles, a method for their production, a coating, or printing composition, comprising the metal oxide nanoparticles and the use of the composition for coating of surface relief micro- and nanostructures (e.g. holograms), manufacturing of optical waveguides, solar panels, light outcoupling layers for display and lighting devices and anti-reflection coatings. Holograms are bright and visible from any angle, when coated, or printed with the composition, comprising the metal oxide nanoparticles.

The present invention relates to formulations of ink based on nanoparticles of silver and of metal oxides. In particular, the present invention relates to formulations of ink based on nanoparticles of silver and of metal oxides, said inks being stable, having improved conductivity and making it possible to advantageously form electrodes and/or conductive tracks that are particularly suitable for photovoltaic cells, for example on a silicon and/or glass substrate.

The present invention relates to formulations of ink based on nanoparticles of silver and of metal oxides. In particular, the present invention relates to formulations of ink based on nanoparticles of silver and of metal oxides, said inks being stable, having improved conductivity and making it possible to advantageously form electrodes and/or conductive tracks that are particularly suitable for photovoltaic cells, for example on a silicon and/or glass substrate.

In one aspect, provided is a method for producing a semiconducting single-walled carbon nanotube dispersion. This method allows semiconducting single-walled carbon nanotubes to be separated from a single-walled carbon nanotube mixture containing semiconducting single-walled carbon nanotubes and metallic single-walled carbon nanotubes in an aqueous medium, and yet requires only an easily available separation agent and a simple operation.

One aspect of the present disclosure relates to a method for producing a semiconducting single-walled carbon nanotube dispersion. The method includes (A) preparing a single-walled carbon nanotube dispersion to be separated that contains single-walled carbon nanotubes composed of semiconducting single-walled carbon nanotubes and metallic single-walled carbon nanotubes, an aqueous medium, and a nonionic polymer containing a constitutional unit A derived from a monomer represented by the following formula (1), and (B) centrifuging the single-walled carbon nanotube dispersion to be separated and then collecting a supernatant containing the semiconducting single-walled carbon nanotubes from the centrifuged single-walled carbon nanotube dispersion. A content of the constitutional unit A in all constitutional units of the polymer is 2 mol % or more. The polymer is water soluble.

CH.sub.2═CR.sup.1—COO—(EO).sub.p(PO).sub.q—R.sup.2   (1)