| 摘要 |
434,984. Preserving wood &c. LINDBLAD, A. R., 17, Vastra Trõdgardsgatan, Stockholm. June 12, 1934, No. 17370. [Class 140] Wood or other vegetable matter is preserved by impregnation with a solution containing an alkaline earth compound, e.g. a calcium, barium, strontium or magnesium compound, arsenic acid or a salt thereof, and an organic acid e.g. acetic or formic acid, so that on evaporation of the solvent a difficultly soluble alkaline earth metal arsenate is left in the wood. In modifications the arsenic acid or organic acid constituents may be chemically combined with the alkaline earth metal constituent. Examples describe aqueous solutions of (1) lime, arsenic acid and acetic acid, (2) calcium arsenate and acetic or formic acid, (3) calcium acetate and arsenic acid kept acid with a small quantity of acetic or formic acid. The impure calcium acetate obtained in charring wood known as grey lime or grey chalk may be used. Staining or colouring agents may be added to the impregnating solution. Specification 293,908, [Class 140], is referred to. |
