Abstract: The invention relates to a layer structure comprising a substrate layer and a layer, which comprises a plurality of silicon oxide particles, wherein said silicon oxide particles have a positively charged surface (a PCS layer), which PCS layer is at least partially superimposed to the substrate layer and wherein the refractive index of the PCS layer is less than 1.2, a process for preparing the layer structure having a substrate and a PCS layer, a layer structure obtainable by the process, an optical device comprising the layer structure and the use of a PCS layer.

Abstract: The present invention relates to a process for the direct preparation of pyrrolo[3,4-c]pyrroles (DPPs) of the formula pigment compositions containing them and their use for coloring high molecular weight organic materials, such as plastics and paints. The obtained DPPs of the formula I possess a higher color strength, a higher chroma, a purer shade and a higher opacity versus corresponding commercially available DPPs.

Abstract: A method for the preparation of silicium dioxide dispersions is provided, wherein the surface of the silicium dioxide is modified by a treatment with the reaction products, formed in a separate reaction step, of at least one compound of trivalent aluminum or of tetravalent zirconium or a mixture thereof with at least one aminoorganosilane; and the invention also relates to recording sheets for ink jet printing having such a dispersion incorporated in an ink-receiving layer.

Abstract: A method for the preparation of silicium dioxide dispersions is provided, wherein the surface of the silicium dioxide is modified by a treatment with the reaction products, formed in a separate reaction step, of at least one compound of trivalent aluminum or of tetravalent zirconium or a mixture thereof with at least one aminoorganosilane; and the invention also relates to recording sheets for ink jet printing having such a dispersion incorporated in an ink-receiving layer.

Abstract: A method for the preparation of silicon dioxide dispersions is described, wherein the surface of the silicon dioxide is modified by a treatment with the reaction products of a compound of trivalent aluminum with least one aminoorganosilane. These reaction products are formed in a separate reaction step. The present invention also relates to recording sheets for ink jet printing having such a dispersion incorporated in an ink-receiving layer.

Abstract: A method for the preparation of silicon dioxide dispersions is described, wherein the surface of the silicon dioxide is modified by a treatment with the reaction products of a compound of trivalent aluminum with least one aminoorganosilane. These reaction products are formed in a separate reaction step. The present invention also relates to recording sheets for ink jet printing having such a dispersion incorporated in an ink-receiving layer.

Abstract: A recording sheet for ink jet printing is described, which consists of a support having coated onto said support at least two ink-receiving layers, wherein the ink-receiving layer situated next to the support contains nanoporous silicon dioxide with a positively charged surface and at least one binder and the ink-receiving layer situated further away from the support contains nanocrystalline, nanoporous aluminium oxide or aluminium oxide/hydroxide and at least one binder and, optionally, nanoporous silicon dioxide with a positively charged surface.

Abstract: A recording sheet for ink jet printing is provided, which consists of a support having coated thereon at least one ink-receiving layer consisting of binders and at least one nanoporous inorganic compound, wherein the recording sheet contains a polynuclear aluminum hydroxo complex with 30 aluminum atoms. In a preferred embodiment, the surface of the nanoporous inorganic compound is modified by a treatment with the aluminum hydroxo complex with 30 aluminum atoms.

Abstract: A method for the preparation of silicium dioxide dispersions is provided, wherein the surface of the silicium dioxide is modified by a treatment with the reaction products, formed in a separate reaction step, of at least one compound of trivalent aluminum or of tetravalent zirconium or a mixture thereof with at least one aminoorganosilane; and the invention also relates to recording sheets for ink jet printing having such a dispersion incorporated in an ink-receiving layer.

Abstract: A recording sheet for ink jet printing is provided, which consists of a support having coated thereon at least one ink-receiving layer consisting of binders and at least one nanoporous inorganic compound, wherein the recording sheet contains a polynuclear aluminum hydroxo complex with 30 aluminum atoms. In a preferred embodiment, the surface of the nanoporous inorganic compound is modified by a treatment with the aluminum hydroxo complex with 30 aluminum atoms.

Abstract: The present invention relates to a process for the preparation of diketopyrrolopyrroles of the formula (I), wherein A1, A2, A3 and A4 are as defined in the description of the present invention, to new diketopyrrolopyrroles of the general formula I obtainable by the process, and the use of the new diketopyrrolopyrroles of the general formula I for the preparation of inks, colorants, pigmented plastics for coatings, non-impact-printing material, color filters, cosmetics, polymeric ink particles, toners, dye lasers and electroluminescent devices, or as fluorescent markers for immunoassays and fluorescent tracers for leak detection of fluids.

Abstract: A recording sheet for ink jet printing is described, which consists of a support having coated onto said support at least two ink-receiving layers, wherein the ink-receiving layer situated next to the support contains nanoporous silicon dioxide with a positively charged surface and at least one binder and the ink-receiving layer situated further away from the support contains nanocrystalline, nanoporous aluminium oxide or aluminium oxide/hydroxide and at least one binder and, optionally, nanoporous silicon dioxide with a positively charged surface.

Abstract: The present invention relates to a process for the direct preparation of pyrrolo[3,4-c]pyrroles (DPPs) of the formula pigment compositions containing them and their use for coloring high molecular weight organic materials, such as plastics and paints. The obtained DPPs of the formula I possess a higher colour strength, a higher chroma, a purer shade and a higher opacity versus corresponding commercially available DPPs.

Abstract: The present invention relates to a process for the direct preparation of pyrrolo[3,4-c]pyrroles (DPPs) of the formula (1), pigment compositions containing them and their use for coloring high molecluar weight organic materials, such as plastics and paints. The obtained DPPs of the formula I posses a higher color strength, a higher chroma, a purer shade and a higher opacity versus corresponding commerically available DPPs.

Abstract: The present invention comprises a process for preparation of a stir-in pigment composition comprising a treatment of the pigment surface with at least one polymer and/or copolymer using water/solvent emulsion or pure organic solvent, miscible or non-miscible with the polymer or copolymer, or a mixture of these solvents or only water, in the presence of a surfactant, and optionally in the presence of a polar pigment derivative and/or a fluidiser and/or other components, said stir-in pigment composition as such as well as the use of this pigment composition for coloring high molecularweight organic materials.

Abstract: A method for the preparation of silicon dioxide dispersions is described, wherein the surface of the silicon dioxide is modified by a treatment with the reaction products of a compound of trivalent aluminum with least one aminoorganosilane. These reaction products are formed in a separate reaction step. The present invention also relates to recording sheets for ink jet printing having such a dispersion incorporated in an ink-receiving layer.

Abstract: The present invention relates to a process for the direct preparation of pyrrolo[3,4-c]pyrroles (DPPs) of the formula (I), pigment compositions containing them and their use for coloring high molecular weight organic materials, such as plastics and paints. The obtained DPPs of the formula I possess a higher colour strength, a higher chroma, a purer shade and a higher opacity versus corresponding commercially available DPPs.

Abstract: The present invention relates to a process for the preparation of diketopyrrolopyrroles of the formula (I), wherein A1, A2, A3 and A4 are as defined in the description of the present invention, to new diketopyrrolopyrroles of the general formula I obtainable by the process, and the use of the new diketopyrrolopyrroles of the general formula I for the preparation of inks, colorants, pigmented plastics for coatings, non-impact-printing material, color filters, cosmetics, polymeric ink particles, toners, dye lasers and electroluminescent devices, or as fluorescent markers for immunoassays and fluorescent tracers for leak detection of fluids. Furthermore the present invention relates to diketopyrrolopyrrole analogues of the general formula (II), wherein A1, A2 and A3 are defined in the description of the present invention, which are intermediates in the process for the preparation of diketopyrrolopyrroles of the formula I and can be used as crystal growth regulators.