GB316649A - Improvements in the qualities of porous materials by an impregnation process - Google Patents

Abstract

316,649. Johnson, J. Y., (I. G. Farbenindustrie Akt.-Ges.). May 2, 1928. Waterproofing; proofing against bacteria and fungi; proofing processes and compositions.- Porous materials such as wood, millboard, leather, bricks, concrete, and building stone, are impregnated with montan wax bleached by means of a solution of an oxidizing agent, or with esterification or saponification products of such wax, or mixtures of these. Bactericidal or fungicidal agents and other waxes, fats, oils or resins may be added. The bleached montan wax mav be obtained by oxidizing and saponifying crude or purified montan wax in the presence of a strong, preferably mineral, acid. Metallic compounds that possess bactericidal or fungicidal action such as salts of zinc, mercury, copper, &c. may be added, together with carnauba or Japan wax, linseed oil, colophony, or paraffin wax. Phenol or its homologues may also be added. Impregnation may be effected at any suitable pressure or pressures, and the wax may be melted or in solution. In one example, bleached montan wax prepared by simultaneusly saponifying and oxidicing crude or purified montan wax in the presence of a strong acic is allowed to act on dry pine timber at from 100‹ to 110‹ C. at a pressure of 50 to 80 m.m. of mercury until air no longer escapes. The vacuum is then relieved, while the temperature is maintained for about three hours. The bleached montan wax may be replaced by montan wax prepared by partially or wholly converting the free organic acids present in the bleached wax into salts or esters or by converting the carbonyl groups of the said acids or esters into other groups containing no carbonyl hydrogen atom. In a second example bricks are immersed in an esterification product of bleached montan wax and ethylene glycol at the same temperature and pressure as in the first example until all air has escaped. Air or inert gas at a pressure of 10 atmospheres is then forced into the apparatus, and the pressure maintained for 3 hours. Part of the esterification product may be replaced by paraffin wax melting at 52‹ C.