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US 4,731,161 AGranted
Semibleaching liquor for Kraft paper products
AssigneeUnion Camp Corporation
InventorF. Joseph Ehrhardt
Life of this patent
Estimating the term…
Abstract
A process of preparing a bleaching liquor with an improved stability involves mixing of magnesium ions and hydrogen peroxide prior to the addition of sodium hydroxide. The liquor may be used to bleach Kraft wood pulps, obtaining higher brightness levels.
Claims6
A method of preparing a stabilized bleaching liquor which comprises:
- providing an aqueous solution consisting essentially of 0.005 to 0.2 weight percent of a water soluble magnesium salt and 0.05 to 2 weight percent of hydrogen peroxide;
- and
- then adding to said solution 0.05 to 2.0 weight percent of an alkali metal hydroxide.
Dependencies are inferred from the claim text.