Formation of melt-spun acrylic fibers which are well suited for thermal conversion to high strength carbon fibers
US4933128A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 1989 |
| Grant date | Jun 12, 1990 |
| Priority date | — |
| Expiry date | Jul 6, 2009 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01F9/22
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
An acrylic multifilamentary material possessing an internal structure which is well suited for thermal conversion to high strength carbon fibers is formed via a specifically defined combination of processing conditions. The acrylic polymer while in substantially homogeneous admixture with appropriate concentrations (as defined) of C.sub.1 to C.sub.2 nitroalkane and water is melt extruded and is drawn at a relatively low draw ratio which is substantially less than the maximum draw ratio achievable. During the melt extrusion a C.sub.1 to C.sub.4 monohydroxy alkanol preferably also is present in the substantially homogenous admixture. The fibrous material which is capable of readily undergoing drawing next is passed through a heat treatment zone wherein the evolution of residual nitroalkane, monohydroxy alkanol and water takes place. The resulting fibrous material following such heat treatment is subjected to additional drawing to accomplish further orientation and internal structure modification and to produce a fibrous material of the appropriate denier for carbon fiber production. One accordingly is provided a reliable route to form a fibrous acrylic precursor for carbon fiber prod…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.