Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1998-03-11
2000-04-25
Reddick, Judy M.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
159 471, 523343, C08F 800
Patent
active
060545305
ABSTRACT:
An improved process for the continuous production of poly(vinyl alcohol) which involves purifying poly(vinyl acetate) paste exiting from a polymerization reactor and dissolving the substantially pure poly(vinyl acetate) in a hydrolytic alcohol-containing solvent for subsequent saponification to produce poly(vinyl alcohol). Poly(vinyl acetate) paste, containing poly(vinyl acetate), vinyl acetate, and solvent, is heated to a temperature above the glass transition temperature but below a temperature which will degrade the poly(vinyl acetate) and is fed into a flashing area of an extruding devolatilization device. Vinyl acetate and solvent are flashed through vent ports in the flashing area of the devolatilization device and can then be recycled to a polymerization reactor, if desired. A substantially pure poly(vinyl acetate) melt, exiting the flashing area, is conveyed to a mixing area of the devolatilization device where it is mixed with a hydrolytic alcohol-containing solvent to form a solution for subsequent processing in a saponification unit.
REFERENCES:
patent: 4198265 (1980-04-01), Johnson
patent: 4493807 (1985-01-01), Vyvial et al.
patent: 5028648 (1991-07-01), Famili et al.
patent: 5051222 (1991-09-01), Marten et al.
patent: 5084134 (1992-01-01), Mattiussi et al.
patent: 5635568 (1997-06-01), Plochocka et al.
Devolatilization of Polymers, edited by J. A. Biesenberger (Hanser, 1983), pp. 65-85.
"Devolatilization," by J. A. Biesenberger, in Encyclopedia of Polymer Science and Engineering, 2d ed., vol. 4, pp. 745-751 (Wiley-Interface, 1985).
Polymer Handbook, 3.sup.rd ed., edited by J. Brandrup and E. H. Innergut. Wiley, 1989, p. V/71
Carvill Brian Thomas
Frey Beth Ann
Nangeroni James Francis
Webb Stephen Charles
Air Products and Chemicals Inc.
Bongiorno Mary E.
Reddick Judy M.
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