An article for laser marking can comprising: a thermoplastic composition comprising a thermoplastic polymer, an active component comprising at least one of a polymeric unit and an additive, wherein the thermoplastic polymer has a visible transmission of greater than or equal to 80% according to ASTM D1003-00, Procedure A, using D65 illumination, 10 degrees observer, and thickness of 1 mm; and a mark produced by chemical rearrangement of the active component generated by a laser of a first wavelength; wherein the mark exhibits at least one of: (i) a change in optical properties in the region 400 nm to 700 nm when exposed to light having a wavelength less than or equal to 500 nm; and (ii) a change in optical properties in the region of 400 nm to 700 nm when exposed to light having a wavelength greater than or equal to the first wavelength.

An article for laser marking can comprising: a thermoplastic composition comprising a thermoplastic polymer, an active component comprising at least one of a polymeric unit and an additive, wherein the thermoplastic polymer has a visible transmission of greater than or equal to 80% according to ASTM D1003-00, Procedure A, using D65 illumination, 10 degrees observer, and thickness of 1 mm; and a mark produced by chemical rearrangement of the active component generated by a laser of a first wavelength; wherein the mark exhibits at least one of: (i) a change in optical properties in the region 400 nm to 700 nm when exposed to light having a wavelength less than or equal to 500 nm; and (ii) a change in optical properties in the region of 400 nm to 700 nm when exposed to light having a wavelength greater than or equal to the first wavelength.

A micro-optic device, including: a substrate; a plurality of image elements in an image plane; and a plurality of focusing elements, each focusing element focusing light to a focal point on the image plane and magnifying any portion of an image element falling within the focal point to thereby produce an image pixel projected to a user at one or more viewing angles, the focal point having an extent smaller than the image element, wherein each image element includes an image sub-element having a different discernible level of brightness to elsewhere in the image element, the brightness of each projected image pixel being dependent on the proportion of the focal point filled with the image sub-element, and wherein each image sub-element has one or more attributes in the image plane, such that, from a given viewing angle, the brightness of each projected image pixel is dependent on each attribute of each image sub-element.

A diffractive security device is disclosed, including first and second diffractive structures defined in a carrier layer. The first diffractive structure is a diffractive zone plate structure of a continuously curved surface configured such that when the device is illuminated by on-axis light, a first diffraction pattern generated by the first diffractive structure can be viewed from at least a first side of the device at substantially all viewing angles, the first diffraction pattern exhibiting a reference point or reference line relative to which other features of the first diffraction pattern appear to move when the viewing angle is changed. The second diffractive structure is an off-axis diffractive structure configured such that when the device is illuminated by on-axis light a second diffraction pattern generated by the second diffractive structure can be viewed from at least the first side of the device at at least some off-axis viewing angles.

A diffractive security device is disclosed, including first and second diffractive structures defined in a carrier layer. The first diffractive structure is a diffractive zone plate structure of a continuously curved surface configured such that when the device is illuminated by on-axis light, a first diffraction pattern generated by the first diffractive structure can be viewed from at least a first side of the device at substantially all viewing angles, the first diffraction pattern exhibiting a reference point or reference line relative to which other features of the first diffraction pattern appear to move when the viewing angle is changed. The second diffractive structure is an off-axis diffractive structure configured such that when the device is illuminated by on-axis light a second diffraction pattern generated by the second diffractive structure can be viewed from at least the first side of the device at at least some off-axis viewing angles.

The present invention relates to a security element (16) for security papers, value documents and the like, having a microoptical moir-type magnification arrangement for depicting a moir image (84) having one or more moir image elements (86), having a motif image that includes a periodic or at least locally periodic arrangement of a plurality of lattice cells (24) having micromotif image portions (28, 28, 28), for the moir-magnified viewing of the motif image, a focusing element grid (22) that is arranged spaced apart from the motif image and that includes a periodic or at least locally periodic arrangement of a plurality of lattice cells having one microfocusing element (22) each,
wherein, taken together, the micromotif image portions (28, 28, 28) of multiple spaced-apart lattice cells (24) of the motif image each form one micromotif element (50) that corresponds to one of the moir image elements (86) of the magnified moir image (84) and whose dimension is larger than one lattice cell (24) of the motif image.

The present invention relates to a security element (16) for security papers, value documents and the like, having a microoptical moir-type magnification arrangement for depicting a moir image (84) having one or more moir image elements (86), having a motif image that includes a periodic or at least locally periodic arrangement of a plurality of lattice cells (24) having micromotif image portions (28, 28, 28), for the moir-magnified viewing of the motif image, a focusing element grid (22) that is arranged spaced apart from the motif image and that includes a periodic or at least locally periodic arrangement of a plurality of lattice cells having one microfocusing element (22) each,
wherein, taken together, the micromotif image portions (28, 28, 28) of multiple spaced-apart lattice cells (24) of the motif image each form one micromotif element (50) that corresponds to one of the moir image elements (86) of the magnified moir image (84) and whose dimension is larger than one lattice cell (24) of the motif image.

Disclosed herein is a method for forming a surface relief microstructure, including the steps of A) applying a curable composition to at least a portion of the frontside of the paper substrate, B) contacting at least a portion of the curable composition with surface relief microstructure, C) curing the composition by using at least one UV lamp which is arranged on the backside of the paper substrate, and D) depositing a metallic layer, and optionally a layer of a transparent high refractive index material, on at least a portion of the cured composition, wherein the UV lamp has an emission peak in a UV-A range of 320 nm to 400 nm and additionally in a near VIS range of 400 nm to 450 nm, the curable composition comprises a photoinitiator which absorbs in the UV-A range and also in the near VIS range.

Disclosed herein is a method for forming a surface relief microstructure, including the steps of A) applying a curable composition to at least a portion of the frontside of the paper substrate, B) contacting at least a portion of the curable composition with surface relief microstructure, C) curing the composition by using at least one UV lamp which is arranged on the backside of the paper substrate, and D) depositing a metallic layer, and optionally a layer of a transparent high refractive index material, on at least a portion of the cured composition, wherein the UV lamp has an emission peak in a UV-A range of 320 nm to 400 nm and additionally in a near VIS range of 400 nm to 450 nm, the curable composition comprises a photoinitiator which absorbs in the UV-A range and also in the near VIS range.

The present invention relates to a method for creating a hidden pattern on a substrate, wherein a liquid treatment composition comprising at least one acid is deposited by inkjet printing onto a substrate, which comprises at least one external surface comprising a salifiable alkaline or alkaline earth compound.