Continuous method for producing a dry, solid polyacrylamide
Abstract
Abstract A process for producing polyacrylamide in a dry and solid form which includes the steps of mixing from 20 to 40% by weight of water and from 60 to 80% by weight of acrylamide to form an aqueous mixture thereof; heating said aqueous mixture to a temperature of between about 50° C and 100° C to form one phase aqueous liquid composition; depositing, on a surface, said one phase aqueous liquid composition and a catalytically effective amount of an aqueous solution of a water soluble polymerization catalyst for the acrylamide, said depositing being done in such a manner so as to form a mixture of said one phase aqueous liquid and said catalytic aqueous solution, said surface being heated to a temperature of between about 50° C and the charring point of polyacrylamide, whereby the acrylamide exothermically polymerizes to form polyacrylamide whereby all the water is evaporated and there is formed a dry, solid polyacrylamide and, after said water has evaporated, removing the polyacrylamide from said surface and, if desired, grinding the polyacrylamide to the desired particle size. It is preferred if the surface is moving at a rate of speed such that the polyacrylamide is brought to the removal point after the water is removed therefrom. In the more preferred exemplary embodiment, the moving surface is in the form of a relatively flat disc moving in a circular manner and is heated by gas burners.
Inventors
- 👤 John Hughes
Bibliographic Details
Claims Analysis
Total Claims: 6References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-27 | 1980-12-27 | 1981-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-27 | 1984-12-27 | 1985-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-27 | 1988-12-27 | 1989-06-28 | $7700.00 | Window Closed / Lapsed |