Polyamides for extrusion applications
US4128599A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1976 |
| Grant date | Dec 5, 1978 |
| Priority date | — |
| Expiry date | Dec 22, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L77/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
There is disclosed a process for preparing polycarbodiimide modified tractable polyamides having unique rheological properties which include increased melt strength and relative viscosity. These polycarbodiimide modified tractable polyamides are prepared by reacting the carboxyl end groups and to a lesser degree the amine end groups of tractable polyamides such as nylon 6,6, which are in a molten state with the polycarbodiimide groups of at least one polycarbodiimide such as poly(4,4'-diphenyl-methane carbodiimide) which both (a) is derived from at least one aromatic diisocyanate which is either unsubstituted or contains up to one methyl substituent on each aromatic ring, and (b) contains at least three carbodiimide units per polycarbodiimide molecule. The resulting polycarbodiimide modified tractable polyamide has improved melt strength and relative viscosity and a decreased number of carboxylic acid and amine end groups. These improved melt strength polyamides also have improved die swell and shear sensitivity characteristics and are generally useful in extrusion applications such as blow molding.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.