A color laser markable article includes at least a first and a second laser markable layer including, respectively, a first infrared dye IR-1 having an absorption maximum in the infrared region .sub.max(IR-1) and a second infrared dye IR-2 having an absorption maximum in the infrared region .sub.max(IR-2), characterized in that the color laser markable layers further include a Diffusion Hindered Molecular Assembly (DHMA) which contains a leuco dye.

A laser markable composition includes (a) an aqueous medium; (b) a leuco dye; (c) an optothermal converting agent; and (d) a color developing agent, characterized in that the color developing agent is a polymer particle capable of forming an acid upon exposure to heat.

As a thermosensitive recording medium utilizes a coloring reaction between a colorless or pale colored electron donating leuco dye and an electron accepting color developing agent, a thermosensitive recording medium using an environment-friendly color developing agent is provided.

Provided is a thermosensitive recording medium having a thermosensitive recording layer comprising a colorless or pale colored electron donating leuco dye and an electron accepting color developing agent on a substrate, wherein the thermosensitive recording layer comprises a gluconolactone as the electron accepting color developing agent.

Encrypted markers that are not readily detectable can be revealed by treatment with a specific reagent used as a developer to reveal a readily detectable physical property of the marker, such as a characteristic fluorescence emission after excitation with a particular excitation wavelength, or to reveal a visible color. The encrypted marker can be developed in situ, or a sample can be removed by brushing, scraping, swabbing or scratching the marked object or item and developing the encrypted marker or a sample thereof with the appropriate developer to reveal an overt marker or optical signal. The encrypted marker may include a DNA taggant.

A security article includes a laser markable layer and a transparent outer layer or sheet having lenticular lenses on its outer surface, both provided, in this order, on an opaque core support, characterized in that the laser markable layer has a dry layer thickness of less than 50 m. An improved contrast is obtained between interlaced images exposed into the security article of the invention.

Encrypted markers that are not readily detectable can be revealed by treatment with a specific reagent used as a developer to reveal a readily detectable physical property of the marker, such as a characteristic fluorescence emission after excitation with a particular excitation wavelength, or to reveal a visible color. The encrypted marker can be developed in situ, or a sample can be removed by brushing, scraping, swabbing or scratching the marked object or item and developing the encrypted marker or a sample thereof with the appropriate developer to reveal an overt marker or optical signal. The marker can be revealed by exposure of the encrypted marker or a sample thereof to the developer in any suitable form, such as a solution, a slurry, a swab, a solid (such as in granular form), or a gas or a vapor that includes a developer.

An aqueous inkjet ink for forming a colour upon heat treatment includes a) an immobilized leuco dye; b) a colour developing agent or colour developing agent precursor; and c) optionally an opthothermal converting agent; wherein the leuco dye is immobilized by being covalently bonded to polymeric particles or by being included in the core of capsules composed of a polymeric shell surrounding a core.

This application relates to a time-temperature indicator based on increased thermal reactivity of a diacetylene upon melt recrystallization and a method of making it. A diacetylene is crystallized into a low thermal reactivity phase from a solvent system and converted into a higher thermal reactivity phase and low sensitivity to UV light by melt re-crystallization.

Non-fungible anti-counterfeit photo-chromic nano-micro three-dimensional tags/labels are designed in such a manner that duplication and counterfeiting of the labels are prevented. The label comprises of a frame quick response (QR) code part (103), which surrounds a three-dimensional sticker part, which consists of a foundation paper (113) made of cellulose, a non-fungible three-dimensional (3D) structure and a fade-resistant transparent plastic sheet (201). The structure consists of multi-colored micro particles (107), silica-infused 3D macro particles (109) and the photo-chromic nano particles (111). The sheet is laminated on the paper after application of dense coating of particles. The code part contains all information about the sticker part and is scannable by a specific application module, which allows to scan the code part to recognize the data in the code part, to direct the data to a customer's database server, which instantly maps the code data with the scanned image that is stored in its database to verify label authenticity. If the data matches with each other, the backend server sends a message to the application module that the product is genuine. In case of any variation between the scanned and stored data, the system sends a counterfeit alert to the application user, instantly requests to take the GPS coordinates of the location and sends report to manufacturer's designated contact.

A laser markable composition includes (a) an aqueous medium; (b) capsules composed of a polymeric shell surrounding a core; (c) a colour developing agent or colour developing agent precursor; and (d) an optothermal converting agent; characterized in that the core of the capsule contains a leuco dye.