Continuous process for manufacturing microporous battery separators and battery separators made thereby
Abstract
Abstract Battery separators are formed continuously by placing an aqueous phenolaldehyde resin precursor solution onto a sloped steel or polyfluorocarbon pressure belt which moves upward to a point where it meets another superposed pressure belt of the same material, heating the solution, as it passes through the space between the synchronously moving belts, at a temperature sufficient to cause gellation without loss of water, drying the resulting water-containing sheet after it leaves the confined belt area, curing, and cutting the dry sheet to desired specifications. The resin precursor solution preferably contains resorcinol as well as a thermoplastic resin dispersion. Fillers and fibers may be incorporated.
Inventors
- 👤 Robert E Sherwood
- 👤 Erhard Decker
Bibliographic Details
Claims Analysis
Total Claims: 3References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-11-22 | 1975-05-24 | 1975-11-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-22 | 1979-05-24 | 1979-11-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-22 | 1983-05-24 | 1983-11-23 | $7700.00 | Window Closed / Lapsed |