Optische Diffusoren, erhalten durch Schmelzmischung von unverträglichem Material

摘要

A process for producing a light diffusing sheet material comprises: (a) selecting a first optically clear material and a second optically clear material, which have different indices, are immiscible in one another, and have a viscosity ratio between 0.05 and 10 measured at the processing temperature; (b) dispersing the first optically clear material in the second optically clear material by mechanical mixing, e.g. by melt mixing or compounding and (c) forming a film from the mixture. The film is caused or allowed to harden to fonn the sheet material. The invention further relates to sheet diffusers made by the process. In preferred embodiments, the material is oriented, e.g. by stretching after extrusion but before it has hardened, or by the extrusion process itself, so as to possess asymmetric diffusing properties.