GB595366A - Synthetic resinous materials and process of making same - Google Patents

Abstract

Thermosetting resinous products containing salt-forming sulphonate groups are formed by heating at a pH of 4-10, one or more of formaldehyde, acetaldehyde, butyraldehyde, furfuraldehyde and benzaldehyde, together with a water-soluble metal salt of sulphurous acid and a carbamide, a polyaminodiazine or a polyamino triazine or mixtures thereof, at least two amino groups of which are primary, 0.5-2.0 mols. of aldehyde being used per reactive amino group and the salt yielding 0.05-0.4 mol. of bisulphite per mol. of aldehyde. The term carbamide includes urea and its derivatives, thiourea, dicyandiamide, guanidine or mixtures thereof. Amino - azines specified are 2,6-diamino - 1,3 - diazine; 5 - methyl - 2,6 - diamino - 1,3-diazine; 4-chloro-2,6-diamino-1,3-diazine; polyamino pyrimidines; melamine; melam; ammeline; thioammeline; b - b 1 - bis - thio - ammeline diethyl ether and similar compounds as described in Specification 543,256. Sulphenous acid salts of the alkali metals are particularly useful. The aldehyde and amino compound may be reacted together first and the product reacted with the sulphite, or the aldehyde and sulphite may be reacted first and the product reacted with the amino body or all three reactants may be mixed together at the outset. The preferred temperature range is from 60 DEG C. to the boiling point of the mixture. The product may be concentrated or dried, e.g. by heating with or without vacuum, drum-drying or spray-drying. Examples describe the preparation of resins from (1) urea and formaldehyde in presence of sodium metabisulphite; (2) melamine and formaldehyde in presence of sodium sulphite; (3) urea and acetaldehyde in presence of sodium metabisulphite; (4) melamine, urea and formaldehyde in presence of sodium sulphite. All the products were water-soluble. They are suitable for making films, for treating textiles, for addition to paper pulp in the beater to make paper of high wet strength, for impregnating fibrous materials such as paper, cloth or wood. They may be used as ion exchange resins, for casting or laminating, if desired in conjunction with plasticisers, pigments, fillers, starch, cereal or wood flour. The metal attached to the sulphonate group may be replaced by another metal, e.g. a heavy metal. Thus, cloth or wood may be impregnated with a solution of a resin containing a sodium sulphonate group and then treated with a solution of a salt, e.g. copper sulphate, to exchange the sodium atoms for copper (see Group VIII). Specifications 595,367, [Group VIII], and 595,368 are referred to.