Polypropylene/polystyrene polymer blend, improved fibers produced from the blend and method of manufacturing
US6248835A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 5, 1998 |
| Grant date | Jun 19, 2001 |
| Priority date | — |
| Expiry date | Nov 5, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2967
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A polymer blend, fibers manufactured from the blend and method of producing the fibers is disclosed. The polymer blend includes from 92 wt % to 98.5 wt % of a base polypropylene having a melt flow rate of less than 20 g/10 min, and a maximum draw ratio D, a Crimp Stability of CS, when drawn into filaments at 1000 m/sec, and from 8 wt % to 1.5 wt % of an amorphous polystyrene having a melt flow rate of less than 15 g/10 min. The polymer blend is drawable at greater than 800 m/sec to produce filaments having a maximum draw ratio of D.sub.2, the ratio of D.sub.2 : D.sub.1, being greater than 1.15:1 and a Crimp Stability of CS.sub.2, the ratio of CS.sub.2 : CS.sub.1 being greater than 1.45. Preferably, the base polypropylene has a melt flow rate of between 8 and 15 g/10 min. In one embodiment, the amorphous polystyrene is characterized by a melt flow between 2 and 15 g/10 min., a tensile strength of between 6000 and 9000 psi, a modulus of between 250,000 and 500,000 psi, a flexural strength of between 8000 and 16,000 psi, a flexural modulus of between 300,000 and 500,000 psi, a Vicat softening point of between 180.degree. F. and 240.degree. F., and an annealed heat distortion of betwee…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.