FIELD: cellulose derivative materials. SUBSTANCE: cellulose triacetate film-forming composition contains 8-10% cellulose triacetate with acetyl number 61.7%; 0.025-0.50% organosilicon block copolymer including product of heterofunctional condensation of (i) phenolphthalein and terephthalic acid chloride-based oligomeric acrylate with (ii) α,ω-bis-diethylamino- oligodimethylsiloxane, wherein ratio of arylate to siloxane units in blocks is 20: 35 and which shows characteristic viscosity 0.044 cu.m/kg in tetrachloroethane at 20 C; and organic solvent to 100%. Films manufactured from these compositions are characterized by elevated light resistance, number of macromolecule ruptures after UV irradiation being several times decreased. EFFECT: improved consumer's and working characteristics of films. 1 tbl, 12 ex
