The invention generally relates to a security sheet or document having one or more enhanced watermarks. In one exemplary embodiment, the inventive security sheet or document is a single-ply paper that is made up of a paper layer including one or more watermarks, and a micro-optic security device (e.g., a patch or thread) that at least partially covers an upper or face portion of the watermark(s). The overlying patch or thread increases the durability of the watermark(s), thereby allowing for the watermark(s) as well as reduced fiber density areas therein to be made larger, and further allowing for the reduced fiber density areas to be made thinner. In a preferred embodiment, the micro-optic security device projects one or more synthetic images that coordinate or link in with the watermark design(s). In a more preferred embodiment, the micro-optic security device offers a machine detectable/readable feature in the form of enhanced IR-brightness, especially when measured in transmission. As will be readily appreciated, the inventive security sheet or document offers greatly improved counterfeit-resistance.

Security threads or stripes include a substrate and i) a first optically variable layer imparting a first different color impression at different viewing angles, ii) a second optically variable layer imparting a second different color impression at different viewing angles, iii) a first color constant layer having a color matching the color impression of the first or second optically variable layer at a first viewing angle, iv) a second color constant layer having a color matching the color impression of the first or second optically variable layer at a second viewing angle, and v) one or more material-free regions, wherein the first optically variable layer, the second optically variable layer, the first color constant layer, the second color constant layer and the one or more material-free regions are jointly visible from one side of the security thread or stripe.

Security threads or stripes include a substrate and i) a first optically variable layer imparting a first different color impression at different viewing angles, ii) a second optically variable layer imparting a second different color impression at different viewing angles, iii) a first color constant layer having a color matching the color impression of the first or second optically variable layer at a first viewing angle, iv) a second color constant layer having a color matching the color impression of the first or second optically variable layer at a second viewing angle, and v) one or more material-free regions, wherein the first optically variable layer, the second optically variable layer, the first color constant layer, the second color constant layer and the one or more material-free regions are jointly visible from one side of the security thread or stripe.

The invention relates to a filter element for fluid filtration, in particular for hydraulic fluid, consisting of element components, such as a preferably pleated and multi-layer filter material (10) that extends between two end caps (26) and at least partially comprises a fluid-permeable supporting tube (14) forming a hollow cylinder, characterized in that at least one element component of the filter element is provided at least partially with at least one luminescent material or another marker in such a manner that said material or marker is excited to a characteristic, detectable wave emission when exposed to a certain exciter wave or wave spectrum.

The invention relates to a filter element for fluid filtration, in particular for hydraulic fluid, consisting of element components, such as a preferably pleated and multi-layer filter material (10) that extends between two end caps (26) and at least partially comprises a fluid-permeable supporting tube (14) forming a hollow cylinder, characterized in that at least one element component of the filter element is provided at least partially with at least one luminescent material or another marker in such a manner that said material or marker is excited to a characteristic, detectable wave emission when exposed to a certain exciter wave or wave spectrum.

The present invention relates to a zinc sulphide phosphor and to a process for producing same. The invention further relates to a security document or document of value, to a security feature and to a method for detecting same. The phosphor according to the invention can act as electroluminescent phosphor and thus be excited by an electrical field, and this can result in emission of electroluminescent light in the blue and/or green color region of the visible spectrum. The phosphor can moreover be excited by UV radiation in the wavelength range than 345 nm to 370 nm, and can thus emit photoluminescent light in the blue color region of the visible spectrum. The phosphor can moreover be excited by UV radiation in the wavelength range from 310 nm in 335 nm, and can thus emit photoluminescent light in the green color region of the visible spectrum.

The present invention relates to a zinc sulphide phosphor and to a process for producing same. The invention further relates to a security document or document of value, to a security feature and to a method for detecting same. The phosphor according to the invention can act as electroluminescent phosphor and thus be excited by an electrical field, and this can result in emission of electroluminescent light in the blue and/or green color region of the visible spectrum. The phosphor can moreover be excited by UV radiation in the wavelength range than 345 nm to 370 nm, and can thus emit photoluminescent light in the blue color region of the visible spectrum. The phosphor can moreover be excited by UV radiation in the wavelength range from 310 nm in 335 nm, and can thus emit photoluminescent light in the green color region of the visible spectrum.

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.

The invention generally relates to a security sheet or document having one or more enhanced watermarks. In one exemplary embodiment, the inventive security sheet or document is a single-ply paper that is made up of a paper layer including one or more watermarks, and a micro-optic security device (e.g., a patch or thread) that at least partially covers an upper or face portion of the watermark(s). The overlying patch or thread increases the durability of the watermark(s), thereby allowing for the watermark(s) as well as reduced fiber density areas therein to be made larger, and further allowing for the reduced fiber density areas to be made thinner. In a preferred embodiment, the micro-optic security device projects one or more synthetic images that coordinate or link in with the watermark design(s). In a more preferred embodiment, the micro-optic security device offers a machine detectable/readable feature in the form of enhanced IR-brightness, especially when measured in transmission. As will be readily appreciated, the inventive security sheet or document offers greatly improved counterfeit-resistance.