METHOD OF PREPARING LIGHT FILTER FOR SIGHT PROTECTION Russian patent published in 1994 - IPC

FIELD: protecting and optimizing of sight on looking videopictures. SUBSTANCE: chlorinated polyvinylchloride and industrial carbon-based dry rolled paste is dissolved in methyl methacrylate followed by introducing fat-soluble pure blue dyestuff or green anthraquinone 2 ZH, isobutyric salicylate and azodinitrile. The resulting mixture is polymerized so that monomer conversion of 3 - 4% is achieved followed by polymerization in a plane-parallel form producing a light filter ranging in thickness from 2,5 to 3,5 mm. EFFECT: higher quality of product, non-polluting process. 1 tbl