POLARIZING OPTICAL ELEMENTS AND METHOD FOR PREPARING POLYURETHANE-CONTAINING FILMS

摘要

Described is a method of preparing a cured, non-elastomeric polyurethane-containing filmincluding: a) providing as a first component comprising a polyurethane material having isocyanate functional groups; b) providing as a second component a material having active hydrogen-containing functional groups that are reactive with isocyanate; c) combining the first and second components to form a reaction mixture; d) casting the reaction mixture onto a support substrate in a substantially uniform thickness to form a film thereon; e) heating the film on the support substrate to a temperature and for a time sufficient to yield a cured film; and f) removing the cured film from the support substrate to yield a non-elastomeric polyurethane-containing free film. The free film is non-birefringent. Optical elements and articles prepared from the films are also provided.