Methods and systems for optical effects in pigments, inks, and on media. One aspect of this disclosure involves a pigment particle which includes a core, having a fluorescent material and having a spherical shape, and a shell surrounding the core; the shell includes a photochromic material which has a first optical property in a first light source and a second optical property in a second light source which includes a set of wavelengths not sufficiently present in the first light source. The second optical property attenuates an emitted radiation from the fluorescent material. Other aspects are also described.

Methods and systems for optical effects in pigments, inks, and on media. One aspect of this disclosure involves a pigment particle which includes a core, having a fluorescent material and having a spherical shape, and a shell surrounding the core; the shell includes a photochromic material which has a first optical property in a first light source and a second optical property in a second light source which includes a set of wavelengths not sufficiently present in the first light source. The second optical property attenuates an emitted radiation from the fluorescent material. Other aspects are also described.

A method of detecting temperature of an electrical terminal. The method includes: applying a material patch to a surface of the electrical terminal, the material patch containing a polymer matrix with a polymeric positive temperature coefficient material which contains a mixture of electrically conductive magnetic particles, whereby the material patch does not appreciably increase the electrical resistance or thermal capacitance of the electrical terminal; and remotely sensing a change in the material patch with an electrically isolated circuit which is external to the electrical terminal to determine if the electrical terminal is operating at a safe temperature to optimize current flow across the electrical terminal.

The present invention relates to a coating of the surface of an electrical household appliance comprising a decoration (a) comprising a pigmentary compound B1VO4 having a ΔE* in the coating greater than or equal to 11 between ambient temperature and 150° C., ΔE* being defined by the formula CIE1976 in the CIELAB colour space: Formula (I): L1*, a1* and b1* characterising the values L*a*b* of said compound at ambient temperature; L2*, a2* and b2* characterising the values L*a*b* of said compound at 150° C.

The present invention relates to a coating of the surface of an electrical household appliance comprising a decoration (a) comprising a pigmentary compound B1VO4 having a ΔE* in the coating greater than or equal to 11 between ambient temperature and 150° C., ΔE* being defined by the formula CIE1976 in the CIELAB colour space: Formula (I): L1*, a1* and b1* characterising the values L*a*b* of said compound at ambient temperature; L2*, a2* and b2* characterising the values L*a*b* of said compound at 150° C.

An aspect of the disclosure relates to a thin film including an amorphous array of particles including a top surface and a bottom surface opposing each other, the thin film exhibiting thin film interference and further coherent scattering from the amorphous array of particles, wherein the thin film may include first regions and second regions, wherein the thin film interference of the second regions may be suppressed as compared to the first regions. Another aspect of the disclosure relates to a product including an indicium including a thin film in accordance with any of the previous claims, wherein the indicium may include an encoded pattern encoded by the relative position of the second regions to the first regions, wherein the encoded pattern may be visible under specular reflection of light of a pre-determined wavelength. Another aspect of the disclosure relates to a method of producing a thin film.

Provided are processes for producing fluorescent naphthalimide diesters of Formula (I), useful as fluorescent tracer dyes for fluid system leak detection, wherein each of R.sup.1 and R.sup.2 is, independently of the other, a saturated, linear hydrocarbon chain having from 2 to 10 carbon atoms; and each of Z.sup.1 and Z.sup.2 is, independently of the other, a fatty acid moiety having a saturated or unsaturated, linear or branched, hydrocarbon chain having from 8 to 24 carbon atoms, and from 0 to 4 double bonds. Also provided are compositions of the aforesaid diesters of Formula (I). ##STR00001##

The present invention relates to a fluoropolymer-based coating of the surface of a household article comprising at least two decorations (a) and (b) arranged between or in its layers, wherein: (a) is a decoration comprising at least one thermochromic pigment composition in the form of particles consisting of a (Bi1-xAx) (V1-yMy)O4 type pigment, where: —x is 0 or x is from 0.001 to 0.999; —y is equal to 0 or y is from 0.001 to 0.999; —A and M are selected from the group consisting of nitrogen, phosphorus, an alkali metal, an alkaline earth metal, a transition metal, a poor metal, a metalloid or a lanthanide; —A and M are different from each other; and (b) is a decoration comprising a temperature reference pigment composition.

The present invention relates to a fluoropolymer-based coating of the surface of a household article comprising at least two decorations (a) and (b) arranged between or in its layers, wherein: (a) is a decoration comprising at least one thermochromic pigment composition in the form of particles consisting of a (Bi1-xAx) (V1-yMy)O4 type pigment, where: —x is 0 or x is from 0.001 to 0.999; —y is equal to 0 or y is from 0.001 to 0.999; —A and M are selected from the group consisting of nitrogen, phosphorus, an alkali metal, an alkaline earth metal, a transition metal, a poor metal, a metalloid or a lanthanide; —A and M are different from each other; and (b) is a decoration comprising a temperature reference pigment composition.

There is provided rare earth metal complexes of formula (I): ##STR00001##
wherein M is a cation, RE is a rare earth metal; X is a counter anion; and R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are each independently selected from hydrogen, alkyl of 1-8 carbon atoms, aryl, halo, and alkoxy. Also provided is a composition of europium bis(2,2′-bipyridine-N,N′)-trinitrate with a diketonate dopant. The disclosure also provides processes for preparing the rare earth metal complexes. A mark comprising the rare earth metal complexes, and a method of applying the mark, are disclosed. The rare earth metal complexes may be used in printing systems, and for security applications.