Piezochromes Material, piezochromer Verbundwerkstoff und piezochromer Sensor

(A1) Die vorliegende Erfindung betrifft ein piezochromes Material, das im Wesentlichen aus einer Matrix aus einem Polymer oder Copolymer besteht, worin ein Fluessigkristall sowie eine chiral optisch aktive Substanz verteilt vorliegen. Ebenso betrifft die vorliegende Erfindung einen piezochromen Verbundwerkstoff, bei dem eine Schicht des zuvor genannten piezochromen Materials zwischen zwei Polymerfolien eingebettet ist. Das piezochrome Material bzw. der Verbundwerkstoff finden vor allem im Sensorikbereich Anwendung.

DE 102009035363 A1 UPAB: 20110307 NOVELTY - Piezochromic material comprises a matrix made from at least one polymer and/or copolymer, at least one liquid crystal and at least one chiral, optically active substance that is distributed in the matrix. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a piezochromic composite comprising a layer of the piezochromic material, where a polymer film is applied on at least one side, preferably both sides, of the layer of the piezochromic material, and the polymer film is made from polyolefin, polyester, polyvinyl chloride and/or polyamide; (2) preparing the piezochromic material, comprising mixing a mixture of the liquid crystal, the chiral, optically active substance with monofunctional (meth)acrylate monomer and/or multifunctional (meth)acrylate crosslinker, and at least one initiator and polymerizing by exposing to temperature, light and chemical initiation; and (3) preparing the piezochromic composite, comprising the mixing step as above per se, applying the obtained mixture (in layer form) on a polymer film, preferably between two polymer films and polymerizing as above per se. USE - The piezochromic material and/or piezochromic composite are/is useful: in a piezochromic sensor; and as a security feature in bank notes, as pressure sensor in medical technology, or as a part in optical, electrical, optoelectrical piezochrome and/or chromogenic module (all claimed). ADVANTAGE - The piezochromic material is present in the form of elastic and highly ordered system. The piezochromic material, at low pressure effects of below 50 bar, provides a clear visual signal to the human eye, which is mechanically deformed. The piezochromic composite is well reproducible and can be easily prepared.