POLYURETHANE SHEET FOR LIGHT GUIDE PANEL MATERIAL, PROCESS FOR PRODUCING SAME, AND USE OF SAME

摘要

Disclosed are: a polyurethane sheet for a light guide panel, which can keep translucency, has excellent dimensional stability at higher temperatures, and also has excellent flexibility; a process for producing the polyurethane sheet; and use of the polyurethane sheet. The polyurethane sheet is characterized by being produced by mixing a prepolymer comprising a polypropylene glycol ether (MW (average molecular weight): 500 to 1500) and an alicyclic diisocyanate with a polycaprolactone triol (MW:350 to 800) as a crosslinking agent and shaping the resulting mixture into a sheet-like form, and is also characterized by being used preferably as a numeric keypad back light. The process for producing the polyurethane sheet is characterized by adding an alicyclic diisocyanate to a polypropylene glycol ether (MW: 500 to 1500) to prepare a urethane prepolymer, adding a polycaprolactone triol (MW: 350 to 800) as a crosslinking agent to the urethane prepolymer, and shaping the resulting mixture into a sheet-like form.