The present invention firstly relates to a security feature for a security or value document. The security feature comprises a zinc sulfide lurninophore in the form of particles. The zinc sulfide lurninophore has the general chemical formula ZnS: Cu.sub.x, M.sub.y, X.sub.z; here, M represents one or more elements from a group comprising the chemical elements Co, In and Ni; X represents one or more elements from a group comprising the halides F, Cl, Br and I; and the following applies: 0 < x < 0.002 and 0 ≤ y < 0.00015 and 0 ≤ z < 0.00050. The particles each have cubic phase portions and hexagonal phase portions. When excited by an electrical field, the zinc sulfide luminophore emits a first radiation in the range of the light spectrum between 580 nm and 780 nm. When excited by heating the luminophore to a temperature between 100° C. and 150° C., the zinc sulfide luminophore emits a second radiation in the light spectrum. Furthermore, the invention relates to a security and value document, which may for example be a bank note or a passport, an identity card, a driving license or a postage stamp. The invention also relates to a method for detecting and/or verifying the security feature according to the invention.

The present invention firstly relates to a security feature for a security or value document. The security feature comprises a zinc sulfide lurninophore in the form of particles. The zinc sulfide lurninophore has the general chemical formula ZnS: Cu.sub.x, M.sub.y, X.sub.z; here, M represents one or more elements from a group comprising the chemical elements Co, In and Ni; X represents one or more elements from a group comprising the halides F, Cl, Br and I; and the following applies: 0 < x < 0.002 and 0 ≤ y < 0.00015 and 0 ≤ z < 0.00050. The particles each have cubic phase portions and hexagonal phase portions. When excited by an electrical field, the zinc sulfide luminophore emits a first radiation in the range of the light spectrum between 580 nm and 780 nm. When excited by heating the luminophore to a temperature between 100° C. and 150° C., the zinc sulfide luminophore emits a second radiation in the light spectrum. Furthermore, the invention relates to a security and value document, which may for example be a bank note or a passport, an identity card, a driving license or a postage stamp. The invention also relates to a method for detecting and/or verifying the security feature according to the invention.

A reusable notebook is used with heat-erasable ink. The reusable notebook includes a binding configured to hold a plurality of pages, at least one cover, and at least one ready indicator. The ready indicator is configured to indicate that at least one page in the notebook has reached at least a critical temperature. The critical temperature is a predetermined minimum temperature that is sufficient to erase thermochromic ink on the page(s). The indication occurs when the ready indicator is at a temperature equal to or above a predetermined minimum temperature referred to as the ready temperature. When the ready indicator is at or above the ready temperature, the critical temperature of the at least one page is reached.

A system and associated method, the system including an item including a porous polymer layer including a polymer material capable of absorbing a liquid, the polymer material having an index of refraction that is the same or substantially the same as an index of refraction of the liquid, and a substrate layer, where the porous polymer layer is disposed on the substrate layer, and a liquid source comprising the liquid, where the porous polymer layer appears transparent in response to absorption of the liquid from the liquid source by the porous polymer layer.

The present invention relates to a security element for a security paper, a valuable article or the like having a substrate (1), the substrate being at least partially furnished with a coating (2) that is substantially tack free at room temperature, and the coating (2) including at least one radiation-crosslinkable component.

The present invention relates to a security element for a security paper, a valuable article or the like having a substrate (1), the substrate being at least partially furnished with a coating (2) that is substantially tack free at room temperature, and the coating (2) including at least one radiation-crosslinkable component.

Self-cleaning banknotes are provided using coatings, inks and additives which are photo-active and catalytic to reactions which are effective in breaking up organic contaminants or dirt to allow for the self-cleaning of banknotes by ambient light exposure as well as the cleaning of processed banknotes using equipment with more intense optical excitation, thus increasing their usable life. The invention is usable with all substrates and particularly polymeric substrates such as biaxially-oriented polypropylene (BOPP). The invention further discloses a system which allows a certain class of fitness parameters to cause these banknotes to be redirected to a cleaning module, be revaluated, and then either returned to circulation or rejected and/or destroyed. In addition, inks which are photo-catalytic can be used for extending the life of the banknotes in printed regions.

Self-cleaning banknotes are provided using coatings, inks and additives which are photo-active and catalytic to reactions which are effective in breaking up organic contaminants or dirt to allow for the self-cleaning of banknotes by ambient light exposure as well as the cleaning of processed banknotes using equipment with more intense optical excitation, thus increasing their usable life. The invention is usable with all substrates and particularly polymeric substrates such as biaxially-oriented polypropylene (BOPP). The invention further discloses a system which allows a certain class of fitness parameters to cause these banknotes to be redirected to a cleaning module, be revaluated, and then either returned to circulation or rejected and/or destroyed. In addition, inks which are photo-catalytic can be used for extending the life of the banknotes in printed regions.

A composition including a first color shifting pigment having a first color shift that extends from a starting color at normal through a plurality of colors as a viewing angle is increased to a final color, wherein the first color shift rotates counterclockwise relative to, and about, an origin of the L*a*b* color space; and a color filter that transmits a portion of the first color shift of the first color shifting pigment and absorbs a remainder of the first color shift of the first color shifting pigment; wherein the composition has a second color shift different from the first color shift; and wherein the second color shift has a first portion that rotates counterclockwise relative to the origin and a second portion that rotates clockwise relative to the origin is disclosed. A security device including the composition is included. A method of making the composition and a method of authenticating the security device are also disclosed.

Methods and apparatus for invisible luminescent protection for financial and identification documents are described herein. An example apparatus includes an illuminating source to illuminate a sample with light having a first wavelength, a photo element to detect light having a second wavelength and to capture an image of a first pattern printed on the sample, wherein the first pattern is printed on a first area of the sample with clear ink containing inorganic, ceramic particles having a mean diameter of less than one micron and having luminescent properties such that when the particles are illuminated with light having the first wavelength, they emit light having the second wavelength.