The present invention relates to the field of devices and processes for producing optical effect layers (OEL) comprising magnetically bi-axially oriented platelet-shaped magnetic or magnetizable pigment particles, in particular for producing said OELs as anti-counterfeit means on security documents or security articles or for decorative purposes. The process described herein comprises the step of a) applying on a substrate surface a radiation curable coating composition comprising platelet-shaped magnetic or magnetizable pigment particles, b) exposing the radiation curable coating composition to a dynamic magnetic field of a magnetic assembly comprising a Halbach cylinder assembly, and c) at least partially curing the radiation curable coating composition of step b) so as to fix the platelet-shaped magnetic or magnetizable pigment particles in their adopted positions and orientations, said step c) being carried out partially simultaneously or simultaneously with step b).

An approach to printing a nickel precursor ink on a wide range of substrates for electronics and magnetic applications is disclosed. The nickel ink reduces to elemental nickel following heating. The ink was printed using an ultrasonic aerosol printing technique. By sintering the nickel precursor ink in the presence of a homogeneous magnetic field, the reduced nickel complex formed continuously aligned nickel nanofibers axially aligned with the direction of the magnetic field. The fabrication of aligned interlayered nanofiber films provides opportunities to produce structures with enhanced isotropic electrical and magnetic properties. The resistivity of the film was found to be as low as 0.56 mΩ.Math.cm, and the saturation magnetization was measured to be 30 emu/g, which is comparable to bulk Ni. Magnetic anisotropy was induced with an easy axis along the direction of the applied magnetic field with soft magnetic properties.

An apparatus and methods to make a product using supersonic cold-spray deposition of brittle functional materials in fine and micro features down to 10 μm in minimum dimension. The process may use semiconductors such as bismuth and antimony telluride formulations, and hard magnetic materials such as neodymium iron boride and strontium ferrite, and soft magnetic materials such as manganese zinc ferrite, and manganese ferrite materials. In addition, the methods and processes have been demonstrated for materials as soft as graphite and as hard as boron carbide. Micro components have been deposited in square, tapered and elongated shaped features with feature sizes as small as 10 μm in minimum dimensions and applied to flat and highly complex shaped surfaces. This process when combined with other cold spray manufacturing processes allows the total additive manufacturing of complete electronic, magnetic and other complex devices including multiple type of brittle functional materials.

An apparatus and methods to make a product using supersonic cold-spray deposition of brittle functional materials in fine and micro features down to 10 μm in minimum dimension. The process may use semiconductors such as bismuth and antimony telluride formulations, and hard magnetic materials such as neodymium iron boride and strontium ferrite, and soft magnetic materials such as manganese zinc ferrite, and manganese ferrite materials. In addition, the methods and processes have been demonstrated for materials as soft as graphite and as hard as boron carbide. Micro components have been deposited in square, tapered and elongated shaped features with feature sizes as small as 10 μm in minimum dimensions and applied to flat and highly complex shaped surfaces. This process when combined with other cold spray manufacturing processes allows the total additive manufacturing of complete electronic, magnetic and other complex devices including multiple type of brittle functional materials.

A method for manufacturing a device having a three-dimensional magnetic structure includes applying or introducing magnetic particles onto or into a carrier element. A plurality of at least partly interconnected cavities are formed between the magnetic particles, which contact one another at points of contact, by coating the arrangement of magnetic particles and the carrier. The cavities are penetrated at least partly by the layer generated when coating, resulting in the three-dimensional magnetic structure. A conductor loop arrangement is provided on the carrier or a further carrier. When a current flows through the conductor loop, an inductance of the conductor loop is changed by the three-dimensional magnetic structure, or a force acts on the three-dimensional magnetic structure or the conductor loop by a magnetic field caused by the current flow, or when the position of the three-dimensional magnetic structure is changed, a current flow is induced through the conductor loop.

A method for manufacturing a device having a three-dimensional magnetic structure includes applying or introducing magnetic particles onto or into a carrier element. A plurality of at least partly interconnected cavities are formed between the magnetic particles, which contact one another at points of contact, by coating the arrangement of magnetic particles and the carrier. The cavities are penetrated at least partly by the layer generated when coating, resulting in the three-dimensional magnetic structure. A conductor loop arrangement is provided on the carrier or a further carrier. When a current flows through the conductor loop, an inductance of the conductor loop is changed by the three-dimensional magnetic structure, or a force acts on the three-dimensional magnetic structure or the conductor loop by a magnetic field caused by the current flow, or when the position of the three-dimensional magnetic structure is changed, a current flow is induced through the conductor loop.

The present invention relates to the field of the protection of security documents, especially banknotes, against illegal actions such as robbery or theft. In particular, the present invention relates to the field of ink compositions for producing irreversibly magnetically induced images or patterns, said inks comprising multichromal microspheres, preferably bichromal microspheres (1) that are orientable upon application of a magnetic field and that comprise at least a first portion (2) comprising one or more dyes and/or pigments and at least a second portion (3) comprising one or more magnetic or magnetizable materials, wherein said microspheres (1) comprise as the first portion a core (2) having a surface and comprising the one or more dyes and/or pigments and as the second portion a partial coating (3) covering at least a portion of the surface of said core (2) and comprising the one or more magnetic or magnetizable materials.

The present invention relates to the field of the protection of security documents, especially banknotes, against illegal actions such as robbery or theft. In particular, the present invention relates to the field of ink compositions for producing irreversibly magnetically induced images or patterns, said inks comprising multichromal microspheres, preferably bichromal microspheres (1) that are orientable upon application of a magnetic field and that comprise at least a first portion (2) comprising one or more dyes and/or pigments and at least a second portion (3) comprising one or more magnetic or magnetizable materials, wherein said microspheres (1) comprise as the first portion a core (2) having a surface and comprising the one or more dyes and/or pigments and as the second portion a partial coating (3) covering at least a portion of the surface of said core (2) and comprising the one or more magnetic or magnetizable materials.

The invention relates to the field of the protection of security documents such as for example banknotes and identity documents against counterfeit and illegal reproduction. In particular, the invention relates to optical effect layers (OEL) showing a viewing-angle dependent optical effect, devices and processes for producing said OEL and items carrying said OEL, as well as uses of said optical effect layers as an anti-counterfeit means on documents. The OEL comprises a plurality of non-spherical magnetic or magnetizable particles, which are dispersed in a coating composition comprising a binder material, wherein in at least a loop-shaped area of the OEL at least a part of the plurality of non-spherical magnetic or magnetizable particles are oriented such that their longest axis is substantially parallel to the plane of the OEL, and wherein, in a cross-section perpendicular to the OEL and extending from the center of the central area, the longest axis of the oriented particles present in the loop-shaped area forming the impression of the loop-shaped body follow a tangent of either a negatively curved or a positively curved part of a hypothetical ellipse or circle.

The invention relates to the field of the protection of security documents such as for example banknotes and identity documents against counterfeit and illegal reproduction. In particular, the invention relates to optical effect layers (OEL) showing a viewing-angle dependent optical effect, devices and processes for producing said OEL and items carrying said OEL, as well as uses of said optical effect layers as an anti-counterfeit means on documents. The OEL comprises a plurality of non-spherical magnetic or magnetizable particles, which are dispersed in a coating composition comprising a binder material, wherein in at least a loop-shaped area of the OEL at least a part of the plurality of non-spherical magnetic or magnetizable particles are oriented such that their longest axis is substantially parallel to the plane of the OEL, and wherein, in a cross-section perpendicular to the OEL and extending from the center of the central area, the longest axis of the oriented particles present in the loop-shaped area forming the impression of the loop-shaped body follow a tangent of either a negatively curved or a positively curved part of a hypothetical ellipse or circle.