GB1006510A - Treatment of wood - Google Patents

Abstract

The discoloration of Rhodesian Teakwood by sunlight or UV light is reduced by treating the wood successively with an aqueous alkaline solution at its boiling point, with an aqueous acid solution at room temperature, and with an impregnant solution of a UV absorber or a light stable dye at a temperature of 50-78 DEG C. Each treatment step may be carried out with the use of vacuum and/or pressure. The wood may have previously been degassed. The wood may be washed after the alkaline treatment and also after the acid treatment. The alkali may be an alkali metal, calcium, or barium hydroxide or ammonia, the concentration 0.5-10%, and the time of treatment 10-30 min. The alkaline solution may contain a surface active agent. The acid may be hydrochloric or acetic acid, the concentration 0.2 or 2 N, and the time of treatment 10-15 min. A 10% solution of impregnant in methanol or ethanol may be employed for 10-15 min. The impregnant solution may contain an anti-oxidant. The impregnant may be 2-hydroxy-4-methoxybenzophenone, phenylsalicylate, 2(2-hydroxy-51-methylphenyl)benzotriazole (Tinuvin P), or Sudan Orange G. The anti-oxidant may be 2, 2-methylene-bis(4-methyl-tert-butylphenol) or 2, 6-di-tert-butyl-p-cresol.