PROCEDIMIENTO PARA LA OBTENCION DE PREPARACIONES POBRES EN SALES DE PRODUCTOS DE CONDENSACION

PROCEDIMIENTO PARA LA PRODUCCION DE PREPARADOS POBRES EN SAL DE PRODUCTOS DE CONDENSACION BASADOS EN: A) PRODUCTOS AROMATICOS SULFONADOS, B) ALDEHIDOS Y/O CETONAS Y, OPCIONALMENTE, C) UNO O VARIOS COMPUESTOS, SELECCIONADOS DEL GRUPO DE LOS PRODUCTOS AROMATICOS NO SULFONADOS, UREA Y DERIVADOS DE LA UREA, QUE SE CARACTERIZA PORQUE EL ACIDO INORGANICO QUE SE PRESENTA TRAS LA CONDENSACION ES SEPARADO TOTAL O PARCIALMENTE DEL PRODUCTO DE CONDENSACION, SI SE DIERA EL CASO, EN FORMA DE SUS SALES TRAS LA NEUTRALIZACION, HASTA QUE EL CONTENIDO DE SAL INORGANICA ES INFERIOR A UN 10 % EN PESO REFERIDO AL PESO TOTAL DEL PREPARADO. ESTE PROCEDIMIENTO DA LUGAR A UNOS PREPARADOS QUE SON ESPECIALMENTE IDONEOS COMO MATERIAS CURTIENTES, DISPERSANTES Y LICUEFACTORES. The preparation is of low salt content formulations containing condensation reaction products of (A) sulphonated aromatic compounds, (B) aldehydes and/or ketones and (C) optionally one or more compounds chosen from non-sulphonated aromatic compounds or urea (derivatives). The process comprises the separation of at least some of the inorganic acid from the condensation reaction product following condensation until the inorganic acid content is less 10 wt.%, with respect to the formulation. The acid can optionally be neutralised to form a salt before it is separated from the reaction product.Also claimed are (i) formulations (F1) containing reaction products of (A)-(C) with an average degree of condensation less than or equal to 5 and containing less than 10 wt.% inorganic salt, (ii) similar formulations (F2) containing less than 30 (20) wt.% free monomer (with respect to reaction product) and less than 10 (1) wt.% inorganic salt and (iii) formulations containing condensation react ion products prepared by passing an aqueous solution or suspension of a condensation reaction product comprising (A)-(C) through an ultrafiltration membrane having a molecular weight cut-off (MWCO) level greater than 80000 (200000-500000) Dalton.