Stabilized gamma-irradiated polypropylene and sterilizable articles thereof
US4797438A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1987 |
| Grant date | Jan 10, 1989 |
| Priority date | — |
| Expiry date | May 11, 2007 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K5/34926
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Excellent stabilization of polypropylene (PP) is obtained with a hindered amine containing a polysubstituted piperazin-2-one (PSP) moiety, for example, a C.sub.2 -C.sub.12 alkylene connecting two PSP moieties, or a polyalkylene polyamine having pendant substituted oxo-piperazinyltriazine moieties (PIP-T), that is, having pendant triazine rings substituted with PSP substituents. The stabilizers are particularly effective for PP irradiated with high energy gamma-radiation. Irradiated articles made from PP stabilized with such a hindered amine have improved strength and discoloration resistance, compared to articles made from polymer stabilized with several other hindered amines tested, particularly the 2,2,6,6-tetramethyl-4-piperidyl sebacate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.