Method for producing light guide bodies and use thereof in lighting unit

摘要

The present invention relates to a method for producing light guide bodies and to their use in lighting units, for example for liquid crystal displays or for monitors.;In particular, the present invention relates to a method for producing light guide bodies which have a thickness of at most 1 mm and contain at least 80 wt % of polymethyl methacrylate and no light-scattering constituents.

主权项

1. A method for producing a methacrylate-based light guide body having a thickness of between 100 μm and 1 mm, the method comprising extruding a methacrylate-based material in an apparatus followed by smoothing, to produce a methacrylate-based light guide body,
wherein the apparatus comprises
an extruder,an optional melt pump,an optional melt filter,an optional static mixing element,a flat film nozzle,a smoothing mechanism comprising smoothing rolls,and optionally a winder; the flat film nozzle comprises a nozzle lip comprising control elements for adjusting the nozzle lip width, said control elements having a mutual separation of from 11 to 15 mm, such that a nozzle body has an external geometry which is adapted to the shape of the smoothing rolls; a distance from a melt exit edge to a smoothing gap is 80 mm or less; and at least 95 wt % of the methacrylate-based light guide body consists of PMMA, and it does not contain any impact modifiers.