Multi-component stabilizer system for polyolefins pigmented with azo and disazo pigments
US5240977A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 22, 1991 |
| Grant date | Aug 31, 1993 |
| Priority date | — |
| Expiry date | Feb 22, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K5/34926
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
Excellent color stabilization as well as fiber integrity is obtained in bright sunlight at relatively high temperature, in polyolefin (PO) articles pigmented with red, yellow, and orange azo and disazo pigments, by combining the pigment with two `large molecule` primary stabilizers, the first an oxo-piperazinyl-triazine based (PIP-T) hindered amine light stabilizer (HALS), and the second, a 3,5-disubstituted-tert-butyl-4-hydroxybenzoate (3,5-DHBZ). The first contains at least two polysubstituted piperazinone rings in its molecule; the second is a hindered phenol with an ester group in the para- position. Stabilization of the PO's color is obtained for as long as the PO articles themselves are stabilized by the combination of primary stabilizers. With the combination, the pigmented articles are not only thermooxidatively and light-stabilized, but there is exceptionally low color fade. Because fibers may be extruded twice for better distribution of pigment, a small amount, no more than 0.1 phr of secondary melt-stabilizers, may be used. Blue- green- red- orange- and yellow-pigmented PO articles exhibit less than a .+-.3 change in color (color fading) due to degradation of the pigment…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.