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.

The present invention relates to the technical field of varnishes for protecting security documents, such as banknotes, against premature detrimental influence of soil and/or moisture upon use and time. In particular, the present invention provides a hybrid UV-LED radiation curable protective varnish comprising: a) from about 60 wt-% to about 85 wt-% of either a cycloaliphatic epoxide, or a mixture of a cycloaliphatic epoxide and one or more cationically curable monomers other than the cycloaliphatic epoxide; b) from about 3 wt-% to about 15 wt-% of one or more radically curable monomers and/or oligomers; c) from about 1 wt-% to about 6 wt-% of a diaryl iodonium salt; d) from about 0.5 wt-% to about 3 wt-% of a free radical photoinitiator selected from the group consisting of alpha-hydroxyketones, alpha-alkoxyketones, benzyl diketals, benzoin ethers, phosphine oxides, phenylglyoxylates, and mixtures thereof; e) from about 0.01 wt-% to about 5 wt-% of a non-ionic surfactant; and f) a photosensitizer of general formula (I)

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wherein the weight percents are based on the total weight of the hybrid UV-LED radiation curable protective varnish.

An upconverting pigment dispersion includes an upconverting pigment, such as a -NaYF.sub.4 crystal doped with at least one of Erbium, Ytterbium or Thulium. The upconverting pigment dispersion is aqueous and, thus, includes water. A dispersant is added to increase the stability of the upconverting pigment of the dispersion.

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.

A security product is disclosed herein comprising a pouch containing a composition, the composition including a mixture of a liquid, a polymer, a light-emitting material and a plurality of marker materials. The pouch may form part of a blocking device blocking an access passage that gives access to a restricted area, such as a manhole, and the composition may be transferred onto an object or individual coming into contact with the composition if an attempt is made to break through the pouch.

A laser-assisted method embeds luminescent taggant particles in the surface of a substrate to provide a covert method of evaluating the authenticity of articles so treated.

A method of applying a pattern formed of two different materials to a pattern support layer includes: providing a die form having a surface with recesses defining the pattern; applying a first curable material to a surface first region, received in some of the first region recesses and partially filling a first region recess set; applying a second curable material to some of the surface first region, the second curable material at least partially fills the first set of the first region recesses; contacting a pattern support layer with the die form surface to cover the recesses containing both the first and second curable materials; separating the pattern support layer from the die form surface, the first and second curable materials in the covered recesses removed therefrom and retained on the pattern support layer; and curing the first and second curable materials during and/or after the second and third steps.

The present invention relates to a method for coating and identifying workpieces which preferably consist at least to some extent of wood, wood materials or the like. For this purpose, a curable liquid is used, preferably comprising ink, which, when cured, contains readable information or can receive said readable information.

Described is a marking for a substrate. The marking comprises at least one luminescent substance (a) and at least one chiral liquid crystal polymer (CLCP) material (b) having a reflection wavelength range that overlaps at least a part of the luminescence wavelength range of (a), provided that at least a part of (b) is not located underneath (a).

The present application relates to an adaptive filter using resource sharing and a method of operating the adaptive filter. The filter comprises at least one computational block, a monitoring block and an offset calculation block. The computational block is configured for adjusting a filter coefficient, c.sub.i(n), in an iterative procedure according to an adaptive convergence algorithm. The monitoring block is configured for monitoring the development of the determined filter coefficient, c.sub.i(n), during the performing of the iterative procedure. The offset calculation block is configured for determining an offset, Off.sub.i, based on a monitored change of the filter coefficient, c.sub.i(n), each first time period, T.sub.1, and for outputting the determined offset, Off.sub.i, to the computational block if the determined filter coefficient, c.sub.i(n), has not reached the steady state. The computational block is configured to accept the determined offset, Off.sub.i, and to inject the determined offset, Off.sub.i, into the iterative procedure.