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Verfahren zur Herstellung thermotroper Giessharzsysteme und seine Verwendung

Production of thermotropic casting resin system useful as screen or shading e.g. for building or vehicle.
: Bicer, T.; Schwitalla, C.; Goedeke, H.

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DE 1998-19825984 A: 19980610
DE 1998-19825984 A: 19980610
WO 1999-EP3043 A: 19990504
DE 19825984 C1: 20000316
Patent, Elektronische Publikation
Fraunhofer IBP ()

Es wird ein Verfahren zur Herstellung thermotroper Giessharzsysteme vorgeschlagen, welche mindestens ein Matrixpolymer, das mindestens eine mit dem Matrixpolymer nicht mischbare thermotrope monomere Verbindung einschliesst, wobei das Matrixpolymer und die thermotrope monomere Verbindung so ausgewaehlt sind, dass ihre Brechungsindices im Temperaturbereich unterhalb der fuer die Strukturaenderung massgeblichen Temperatur bis zur Temperatur der Strukturaenderung der thermotropen monomeren Verbindung annaehernd gleich sind und somit das Giessharzsystem in diesem Temperaturbereich transluzent oder transparent ist. Nach dem Loesen der monomeren thermotropen Verbindung in einer photohaertende Oligomere, Reaktivverduenner sowie Photoinitiatoren enthaltenden Matrixloesung zu einem fluessigen, photohaertbaren System findet eine Photobestrahlung unter Sauerstoffabschluss zur Aushaertung statt.


WO 9964488 A UPAB: 20000502 NOVELTY - The process concerns the production of thermotropic casting resin systems containing matrix polymer(s) (I) and included thermotropic monomeric compound(s) (II) immiscible with (I), such that (I) and (II) have about the same refractive index in the temperature range below the temperature at which (II) undergoes structural change and the resin system is translucent or transparent in this temperature range. The process comprises: (i) preparing a liquid, photocurable system by dissolving (II) in a matrix solution containing a photocurable oligomer, reactive diluent and photoinitiator; and (ii) photocure in the absence of oxygen. USE - The system is used as screen or shading in the form of a 0.1-10 mm thick film on or between transparent structural parts, e.g. of glass or plastics (all claimed). Applications include coatings on building and vehicle components exposed to sunlight, which become opaque at high temperature. ADVANTAGE - A stable thermotropic system can be produced cost-effectively and in an environmentally friendly manner in any shape and size. The process avoids solvent emissions (often toxic) and hence the need for special precautions in the workplace. It eliminates long drying periods and restrictions on coating thickness. The process is very simple, uses cheap raw materials and requires little apparatus. When used for shading buildings and vehicles, the system eliminates or reduces the need for air conditioning.