Side chain crystalline polymer as rheology modifier for crosslinked polymer
US6492462B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2000 |
| Grant date | Dec 10, 2002 |
| Priority date | — |
| Expiry date | Dec 19, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F8/00
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
The rheological properties of a crosslinkable resin system are modified by the presence of a side chain crystalline (SCC) polymer (or a similar crystalline polymer which melts over a narrow temperature range). The polymer dissolves in the curable system at temperatures above the melting point of the crystalline polymer (Tp), but when the system is then cooled to a temperature below Tp, at least partially forms a separate phase in the curable system. Below Tp, this separate phase substantially increases the viscosity of the curable system (i.e. makes it thicker than the same system without the crystalline polymer). This is particularly valuable for sheet molding composites (SMCs) in which the increase in viscosity makes the composites less tacky, and for dry film resists (DFRs). Above Tp, the curable system containing the dissolved crystalline polymer has a viscosity which is substantially less than its viscosity below Tp.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.