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US 5,246,739 AGranted
Method for the treatment of wood with metal-lignin salts
AssigneeLignoTech USA, Inc.
InventorStephen Y. Lin
Life of this patent
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Abstract
A method for treatment of wood, whereby the wood is impregnated with a wood preservative composition consisting essentially of an aqueous solution of ammonium salt of lignin and ammonia complexes of certain metal cations such as Cu(NH.sub.3).sub.4.sup.++, Zn(NH.sub.3).sub.4.sup.++, and Hg(NH.sub.3).sub.2.sup.++. the lignin is selected from the group consisting of alkali lignin, organosolv lignin, partially desulfonated sulfite lignin, and modified alkali or organosolv lignin.
Claims12
A method for treatment of wood, comprising the steps of:
- a. forming an aqueous solution consisting of essentially ammonium salt of lignin and a metal ion ammonia complex, said metal ion selected from the group consisting of copper, zinc and mercury, and the composition of said solution having a weight ratio between the metal ions and lignin of from 1:0.01 to 1:1.2;
- b. impregnating wood with said aqueous solution until an effective quantity of metal salts of lignin is absorbed therein for the purpose of preventing the decay of said wood;
- and
- c. Drying the impregnated wood for a sufficient length of time to substantially remove ammonia gas from the wood.
1 more element
Dependencies are inferred from the claim text.