Process for the manufacture of urea-formaldehyde condensation polymers containing sulpho groups

Claim 1

In a process for the manufacture of urea-formaldehyde condensation products the improvement according to which highly disperse, solid urea-formaldehyde condensation products are formed which contain sulpho groups and consist of compact, spherical, agglomerated primary particles having a diameter of less than 1 μm, the process comprising polycondensing a precondensate (P) of urea and formaldehyde said precondensate being a cocondensate in which up to one-third of the urea is replaced by the corresponding molar amount of a comonomer selected from the group consisting of phenol, resorcinol, a cresol, salicylic acid, an acid amide, biuret, a hydantoin and a mixture thereof and a condensation polymer (N) of naphthalenesulphonic acid and formaldehyde in aqueous solution at temperatures of 20° to 100° C to form a gel, the components being added in such ratio that the molar ratio of formaldehyde to urea and the comonomer in the reaction mixture at the moment of gelling is 1.25 to 2, these molar ratios taking into account both the free starting products, formaldehyde, urea and comonomer, and the monomeric starting products chemically bound in the intermediate products.