Electret materials and the method for preparing the electret materials
US5057710A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1990 |
| Grant date | Oct 15, 1991 |
| Priority date | — |
| Expiry date | Jan 11, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S55/39
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
This invention relates to an electret material having thermal stability and capable having high trapped charge quantity and stably existing for a long period of time and a process for preparing the electret material. The electret material is characterized in that it comprises 100 parts by weight of polypropylene, 0.01 to 2 parts by weight of a least one stabilizer selected from among hindered amine, nitrogen-containing hindered phenol, and metal-containing hindered phenol stabilizer and that at least part of the propylene has such a molecular weight distribution that the M(w)/M(n) ratio wherein M(w) is a weight-average molecular weight is 5.5 or less. The electret material can be widely used for various applications and, e.g., is best suited for use in, e.g., various filter materials, wiper materials, absorption materials, masking materials, and dust-proof materials.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.