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US 4,851,168 AGranted
Novel polyvinyl alcohol compositions and products prepared therefrom
AssigneeDow Corning Corporation
InventorsDaniel Graiver, Robert E. Kalinowski, Gary A. Dahlbeck
Life of this patent
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Abstract
Solutions of polyvinyl alcohol in non-aqueous mixtures of dimethyl sulfoxide and up to about 30 weight percent, based on said mixture, of an alcohol containing from 1 to about 4 carbon atoms can be converted to hydrogels, fibers and other useful products.
Claims3
In a method for preparing polyvinyl alcohol fibers comprising the following series of steps:
- (1) preparing a solution containing from 2 to 30 weight percent of polyvinyl alcohol exhibiting a molecular weight of at least 66,000 in a solvent mixture comprised at least in part of an organic liquid,
- (2) extruding the resultant solution into a bath maintained at a temperature no higher than -20 degrees C. to coagulate said polyvinyl alcohol in the form of a fiber,
- (3) drying said fiber and
- (4) drawing said fiber in a heated gaseous or liquid medium,
- the improvement comprising preparing said solution in a nonaqueous solvent mixture consisting essentially of dimethyl sulfoxide and from 10 to 30 percent, based on the weight of said mixture, of a monohydric alcohol containing from 1 to 4 carbon atoms, extruding said fiber into a bath consisting essentially of a monohydric alcohol containing from 1 to 4 carbon atoms, and drawing said fiber using a draw ratio greater than about 20 .
2 more elements
Dependencies are inferred from the claim text.