MOKUZAIGANSHINHOHO

摘要

A method for the impregnation of wood to prevent attack by harmful agents such as decay fungi or mould fungi and bacteria by the application of an aqueous solution of an alkali lignin modified into a water-soluble form. Impregnation takes place in two stages, these being an initial stage in which the aqueous solution containing the lignin still in its water-soluble form and with a pH not exceeding 10 is applied to the timber, and a second stage in which the lignin is fixed as a water-insoluble form by the application to the timber of a weakly acidic aqueous solution containing metal ions by the addition of metal salt.