GB288228A - Process for the production of condensation products from phenols and aldehydes - Google Patents

Abstract

288,228. Runstharzfabrik Dr. F. Pollak Ges. April 6, 1927, [Convention date]. Phenol-aldehyde condensation products. - In the production of condensation products in the form of a pulverous precipitate from phenols and aldehydes, the condensation is carried out in the presence of dispersively acting substances, such as gum arabic, saponin, tragacanth, dextrine, gelatine, casein or other protective colloids, preferably in dilute solution. The condensation product first forms as small drops, suspended in the liquid, and assumes a pulverulent character on continued heating. This suspension may be poured into water or into solutions of salts or acids, or cooled when a pulverulent product is precipitated. Condensing agents, preferably of a basic character, may be employed, and the condensation is preferably effected in the presence of neutral salts. In a typical example, metacresol mixture and, formaldehyde (30 per cent by weight) are mixed with gumarabic dissolved in water, heated, and twice normal caustic soda solution is added. The finely divided oily condensate is boiled until it assumes a fine pulverulent form. By the addition of cold water or dilute acid, a sand-like powder is precipitated which is filtered off. Other examples are given, in one of which a precipitate insoluble in alcohol or alkalies is formed by continued boiling. Other aldehydes such as acetaldehyde, furfural, acrolein &c. may be used.