Cellulosic materials capable of absorbing water of aqueous solutions, and their production
AssigneeCentre Technique De L'industrie Des Papiers, Cartons Et Celluloses
InventorsSolange Sangenis, Gilbert Guiroy, Jean Quere
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Abstract
Cellulosic materials having a high capacity for absorption of water or aqus solutions, a large volume:weight ratio and a high resilience are produced by an acid-catalyzed cross-linking reaction in a reaction medium of low water content from a cellulosic or lignocellulosic material in the form of individual, substantially dehydrated, non-swollen and inter-fibre-bonds free fibres.
Claims27
In a method of treating cellulosic materials by cross-linking said materials with a cross-linking agent in the presence of an acid catalyst, the improvement that comprises putting the cellulosic material to be treated with the cross-linking agent and acid catalyst into the form of dry, substantially dehydrated, non-swollen individualized fibers devoid of inter-fiber bonds, the inter-fiber bonds, if present initially, being broken, and contacting said material in said form, with a medium containing said cross-linking agent and said acid catalyst, the water content of said medium being sufficiently reduced to avoid swelling of the fibers during cross-linking thereof.
A method of treating a cellulosic material which comprises subjecting said material being in the form of a wet mass of individualized cellulosic fibers substantially free of inter-fiber bonds to at least one solvent-exchange treatment with a water-miscible solvent capable of extracting water from the fibers without swelling thereof until the fibers are sufficiently dehydrated to substantially exclude the formation of inter-fiber bonds upon subsequent drying, removing the solvent to obtain fibers devoid of interfiber bonds and in a substantially individualized, debydrated and non-swollen state, contacting said fibers in such state with a liquid medium containing such cross-linking agent and said acid catalyst and having a water content sufficiently reduced to avoid swelling of said fibers during the subsequent cross-linking reaction of said cellulosic material in contact with said medium.
Dependencies are inferred from the claim text.