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US 4,229,252 AGranted
Additives for ozone bleaching
AssigneeWeyerhaeuser Company
InventorMichael D. Meredith
Life of this patent
Estimating the term…
Abstract
In bleaching wood pulp with ozone a small amount of alcohol enhances the bleaching. The effect appears to be most pronounced with aliphatic alcohols having the hydroxyl group on an end carbon. The concentration of alcohol is in the range of 0.0000001 to 0.03 moles per liter of the liquid phase.
Claims14
The process of enhancing the bleaching efficiency of ozone, based on the degree of delignification, when bleaching cellulosic fiber with ozone comprising
- providing said fibers in a liquid phase at a consistency in the range of 0.01-4.9%, said liquid phase comprising water and a water-soluble alcohol, said alcohol being present in an amount in the range of 0.0000001 to 0.03 moles per liter of said liquid phase, and
- mixing an ozone-bearing gas with said liquid phase.
The process of bleaching cellulosic fibers with ozone comprising
- reacting said fibers and ozone in the presence of a liquid phase at a consistency in the range of 0.01-4.9%, said liquid phase comprising water and a water-soluble alcohol, said alcohol being present in an amount in the range of 0.0000001 to 0.03 moles per liter of said liquid phase.
Dependencies are inferred from the claim text.