| 摘要 |
Stabilizing mixtures for plastic materials containing polypropylene comprise (a) a tocopherol or other 6-chromanol compound and (b) a phosphorus-containing secondary antioxidant of formula (I) and typified by 2,2'-ethylidene-bis(4,6-di-tert.butylphenyl) fluorophosphite and 2,2'-methylene-bis(4,6-di-tert.butylphenyl) octylphosphite in a weight ratio (a):(b) of from about 1:0.5 to about 1:20. Closely related stabilizing formulations for plastic materials comprise (a) alpha -tocopherol and (b) one or more polyhydroxy compounds in a weight ratio (a):(b) of from about 1:0.5 to about 1:4, and three-component mixtures for plastic materials containing polypropylene comprise (a) about 4-50 % by weight of alpha -tocopherol, (b) about 4-70 % by weight of a phosphorus-containing secondary antioxidant of the aforementioned formula (I) and (c) about 4-70 % by weight of a polyhydroxy compound, whereby the total percent by weight of the three components (a), (b) and (c) amounts to 100. Such stabilizing mixtures or formulations can be produced by mixing the appropriate components in the appropriate weight ratios. The invention also concerns plastic materials or articles made therefrom having incorporated therein the stabilizing mixture or formulation, and the use of said stabilizing mixtures or formulations for stabilizing plastic materials. A further aspect of the invention is represented by the so stabilized plastic materials containing polypropylene and articles made therefrom whenever these have been subjected to gamma -irradiation at a dose of from 0.5 to 5.0 Mrad. |
