Pigment for use e.g. in holography or document authentication has a diffractive structure with a spatial periodicity of at least a multiple of the longest wavelength of UV light

A pigment with a surface region whose smallest dimension is a multiple of the longest wavelength (ca. 400 nm) of UV light has on at least one surface region a definite diffractive structure with a space periodicity of at least a multiple of the longest wavelength (ca. 400 nm) of UV light. An Independent claim is also included for the production of the pigment by (1) coating a film-like carrier having a definite diffraction structure in or on it with a sealing agent; and (2) comminuting the carrier.

Composite adhesive for optical and optoelectronic applications

A composite adhesive for optical and opto-electronic applications contains the following: (a) transparent polymers and/or polymerisable oligomers and/or monomers suitable for use as adhesive; (b) nanoscale inorganic particles; (c) if required, compounds for the surface modification of the inorganic particles; and (c) if required, a cross-linking initiator. The composite adhesive can be used for connecting individual components of optical or opto-electronic elements and for constructing such elements.

Process for producing an electrically conductive connection

Process for the preparation of encapsulated metal colloids as inorganic color pigments

Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von eingekapselten Metall-Kolloiden als anorganische Farbpigmente, gekennzeichnet durch folgende Verfahrensschritte: a) Umsetzung einer oder mehrerer glasbildender Komponenten nach dem Sol-Gel-Verfahren, um ein Sol zu erhalten; b) Dispergieren eines Metallsalzes in dem erhaltenen Sol in Gegenwart eines zusätzlichen Reduktionsmittels, um Metall-Kolloide zu bilden; c) Überführen der erhaltenen Dispersion in Xerogel-eingekapselte Metallkolloide durch Sprühtrocknen; d) Erhitzen der erhaltenen Xerogel-eingekapselten Metallkolloide, um diese zu verdichten. The present invention relates to a process for producing encapsulated metal colloids as inorganic color pigments, characterized by the following process steps: a) reaction of one or more glass-forming components by the sol-gel process in order to obtain a sol; b) dispersing a metal salt in the sol obtained in the presence of an additional reducing agent to form metal colloids; c) converting the dispersion obtained into xerogel-encapsulated metal colloids by spray drying; d) heating the xerogel-encapsulated metal colloids obtained to densify them.

Prodn. of photochromic glass for optical lens, sensor and recording medium - by hydrolysis and condensation, reacting obtd. sol with silver salt soln., condensing sol to gel, drying and comminuting to fine powder, etc.

Prodn. of photochromic glass using sol-gel method comprises: (a), in a reaction medium, subjecting soluble cpds. of elements of the base glass to hydrolysis and condensation forming a sol. of liq. consistency; (b) reacting the sol with a Ag-salt soln.; (c) condensing Ag-contg. sol to a gel; (d) drying gel and comminuting to a fine powder; (e) treating gel powder with a halide cpd.; and (f) thermally sealing the powder to a glass. The photochromic glass produced by the above method also claimed. The base glass is pref. alumino-boro silicate or boro silicate glass. The reaction medium is alcoholic or aq./alcoholic solvent. Hydrolysis and condensation are pref. carried out in the presence of an acidic or basic condensation catalyst. In step (b), the sol is pref. irradiated before and/or during condensation with energy-rich radiation. The gel powder in (e) is pref. treated with soluble Cl and/or Br. The sol or gel powder is pref. doped with at least one of Cu, Pd, Au, Pb and the lanthanides. USE/ADVANTAGE - The glass is used as an optical lens, thermo-optical sensor or optical recording medium. It can be produced at lower temps. and is discoloured at lower temps with actinic radiation

Composition with non-Newtonian behavior

Beschrieben werden eine Zusammensetzung mit nichtnewtonschem Verhalten, umfassend einen Matrixbildner und nanoskalige Feststoffteilchen, bei der die Oberflächenladung der Teilchen durch Umsetzung mit einer Säure oder Base erhöht worden ist, und ein Verfahren zur Herstellung dieser Zusammensetzungen. Das Verfahren eignet sich zur Einstellung der Rheologie von Materialien. There is described a composition with non-Newtonian behavior, comprising a matrix former and nanoscale solid particles, in which the surface charge of the particles has been increased by reaction with an acid or base, and a method for producing these compositions. The method is suitable for adjusting the rheology of materials.