GB269973A - Improvements in and relating to the manufacture of resin-like bodies - Google Patents

Abstract

269,973. Griffiths Bros. & Co., London, Ltd., and Britton, R. P. L. Jan. 27, 1926. Polymerization or condensation products of aromatic alcohols; condensation products of formaldehyde and aromatic hydrocarbons.-Resinous bodies soluble in organic solvents are obtained by treating monohydric aromatic side-chain alcohols with condensing agents. The condensing agents, such as sulphuric or phosphoric acid or phosphorus pentoxide, may be used singly or in combination, and are preferably taken in such amount that at least one-fifth of a molecule is present for each molecule of alcohol. The initial stages of the reaction are generally carried out at a temperature not higher than 180‹ C., but the temperature may be raised later to about 180‹ C. to regenerate the condensing agent. The reaction may be carried out under pressure. The alcohol may be produced in situ by reaction between an aromatic hydrocarbon and formaldehyde, or a substance giving rise thereto. In this modification only phosphoric acid or phosphorus pentoxide is used as condensing agent, and the preferred reaction mixture comprises one molecule of condensing agent and five molecules each of hydrocarbon aud formaldehyde; the reaction mixture is preferably maintained in an emulsified condition by agitation. The alcohol or the hydrocarbon giving rise thereto may contain substituents other than hydroxy groups, such as halogen, in the nucleus. The reaction may be carried out in presence or absence of a solvent, such as an excess of hydrocarbon, and the alcohol or its generators may be added in stages to the condensing agent, the latter being regenerated as required between the additions. The products may be purified by dissolving them in an organic solvent and centrifuging the solution, with or without the addition of a little alkali, and if the solvent is volatile in steam the solution may be steam-distilled. Alternatively, the reaction mass may be treated with water and the resin separated and treated with steam, or the resin may be dissolved in a fused hydrocarbon, such as naphthalene, with or without addition of water, and the solution, after evaporation of the acid layer treated to recover the resin. Alternatively, the reaction mass may be treated with steam at super-atmospheric pressure and the resinous layer separated. In any event, the resin may be further purified by treatment with alkali particularly by fusion with lime. Examples describe the condensation of benzyl alcohol with the use of sulphuric acid as condensing agent, the condensation of cinnamic alcohol with the use in turn of phosphoric acid and sulphuric acid as condensing agents, and the condensation of naphthalene and paraformaldehyde with the use as condensing agent of dehydrated phosphoric acid. The products may be dissolved in organic solvents and used as varnishes or paint excipients. Specification 16245/07, [Class 2, Acids and salts, Organic &c.], is referred to.