This invention relates to a process for preparing multi-color dispersions and the multi-color dispersions made thereof.

An electrophoretic medium comprises a fluid, a first, light scattering particle (typically white) and second, third and fourth particles having three subtractive primary colors (typically magenta, cyan and yellow); at least two of these colored particles being non-light scattering. The first and second particles bear polymer coatings such that the electric field required to separate an aggregate formed by the third and the fourth particles is greater than that required to separate an aggregate formed from any other two types of particles. Methods for driving the medium to produce white, black, magenta, cyan, yellow, red, green and blue colors are also described.

The present invention relates to a compound having a novel structure, a photopolymer composition including the compound as a dye, a hologram recording medium produced from the photopolymer composition, an optical element including the hologram recording medium, and a holographic recording method using the hologram recording medium.

The invention provides pigment particles and an organic modification layer formed on a surface of the pigment particles; the organic modification layer is a surfactant layer or a polymer material layer formed on the surface of the pigment particles; an organic matter content W.sub.surf of the specific surface area of the pigment particles is in a range of 0.1-2% g/m.sup.2. The pigment particles provided by the invention have good stability, and the electrophoretic display prepared by using the pigment particles of the invention has good optical performance.

A method for determining hydration of a polymer includes mixing a water-soluble, powdered dye with a powdered polymer and introducing the mixed water-soluble, powdered dye and powdered polymer into a water-based fluid. Full hydration of the powdered polymer is determined when the mixed water-soluble, powdered dye, powdered polymer and water-based fluid comprises substantially no internal optical contrast.

This document relates to materials, such as microcapsules, and methods for detecting and/or quantifying analytes in a sample such as a biological sample. Microcapsules can comprise a hydrogel shell and an aqueous core comprising one or more analyte capture beads. The aqueous core can further comprise one or more analyte detection beads.

Provided are an irreversibly discoloring pigment for preventing overheating, a thermochromic molded article including the same, and a method of preparing the same, and more particularly, a discoloring pigment which becomes discolored when overheated, and then maintains the discoloration even after being cooled to room temperature, a thermochromic molded article including the discoloring pigment, and methods of preparing the discoloring pigment and the thermochromic molded article.

A process for the production of a particle composition containing, at least one resin and at least one pigment is described, said process comprising the following steps: *extrusion of a mixture containing said at least one resin and said at least one pigment without induced heating; *subsequent extrusion, with induced heating, of the mixture obtained from the preceding extrusion; *granulation of the mixture thus obtained. With the abovementioned process it is possible to obtain a composition having granules with an average diameter less than 2 microns and a greater homogeneity than the known processes.

An electrophoretic medium comprises a fluid, a first, light scattering particle (typically white) and second, third and fourth particles having three subtractive primary colors (typically magenta, cyan and yellow); at least two of these colored particles being non-light scattering. The first and second particles bear polymer coatings such that the electric field required to separate an aggregate formed by the third and the fourth particles is greater than that required to separate an aggregate formed from any other two types of particles. Methods for driving the medium to produce white, black, magenta, cyan, yellow, red, green and blue colors are also described.

An article that includes a fluorescent composition having at least one of a fluorescent sensor compound and organic reporter molecules encapsulated in a microsphere structure. When encapsulated, the fluorescent sensor compound and the organic reporter molecules are distributed in a liquid organic matrix. When non-encapsulated, the remaining one of the fluorescent sensor compound and the organic reporter molecules reside in the matrix. In response to a force applied to the composition sufficient to break at least a portion of the microsphere structure, the fluorescent sensor compound and the organic reporter molecules are transformed into a non-reversible fluorescent state exhibiting a quantum yield greater than 0.2. The fluorescent state is objectively visually verifiable without physically contacting the composition.