POLYMERIC COMPOSITION AND OLIGOMERIC 4-CHLORO-9-ARYLOXY- 3,5,8,10-TETRAOXA-4,9,-DIPHOSPIRO-[5,5] UNDECANES AS SYNERGISTS FOR PHENOL POLYMER STABILIZERS Russian patent published in 1997 - IPC

FIELD: chemistry of polymers, more particularly stabilized polymeric compositions. SUBSTANCE: composition comprises (%): 98.50-99.8 polypropylene or propylene-ethylene block copolymer: 0.07-0.50 phenol antioxidant of spatially hindered bis-, tris- or tetrakisphenol and 0.07- 1.00 secondary antioxidant. The composition further comprises 0.05- 0.20% calcium stearate per 99.50-99.81% polymer. The secondary antioxidant which is synergist for phenol stabilizers, the composition comprises oligomeric slightly hydrolizable 4-chloro-9-aryloxy 3,5,8,1- tetraoxa 4,9-diphosphospiro (5,5) undecane in which aryl is tratramethyl bisphenol of general formula: wherein x is single bond or C(CH₃)₂, and n is 1-5. EFFECT: improved properties. 4 cl, 1 tbl