COMPOSITION FOR STABILIZING POLYOLEFINS, AND STABILIZED POLYMERIC COMPOSITION BASED ON POLYOLEFINS Russian patent published in 1996 - IPC

FIELD: manufacture of organic polymers. SUBSTANCE: the object of the present invention is to improve effectiveness of service of stabilizers under UV radiation conditions as well as to improve coloring characteristics of polyolefins which incorporate a stabilizing system, while maintaining the melt flow index and the thermal stability index at the uptimum level for prolonged period of time. The given problem is solved by a polyofin stabilization composition comprising (a) phenol selected from pentaerythritol tetra [3-(3,5-di-tert-butyl- hydroxyphenyl)propionate] and n-octadecyl ester of β- 3,5-di tert-butyl-4-hydroxyphenyl propionic acid; (b) tris (2,4-di-tert-butylphenyl; (c) distearylthiodipropionate at (b+c):a weight ratio from 50: 50 to 80:20 and b:c weight ratio from 99:1 to 90:10, as well as by stabilized polymeric composition based on polyolefins (either high-density polyethylene or low- density linear polyethylene or polypropylene) and 0.01- 5.0 wt % of said stabilizing composition. EFFECT: improved properties of the composition. 4 cl, 2 cl