Abstract: A U.F. foam that is diamensionally stable, but low in formaldehyde, was made by adding to a conventional solution of a urea formaldehyde resin precondensate, before foaming, up to 50% urea, relative to the solid resin substance, and one or several connecting agents from the group of sulfurous alkyl compounds, saturated monobasic carbonic acids, saturated and unsaturated dicarbonic acids, purine compounds, inorganic acids of the group of halogens and chalcogens, and their salts, phosphoric acids and their salts, alkali metal salts and alkaline earth metal salts, in such quantity and in such a way that the pH of the resulting solution remains above 7; and subsequently foaming the solution with a hardener/foaming-agent solution in the conventional manner.

Abstract: To obtain a UF foam which is low in formaldehyde, yet is dimensionally stable, up to 96% urea is dissolved in an approximately 10 to 30% aqueous extract of an alkyl, aryl or alkaryl sulphonic acid, said solution being mixed with a conventional hardener/foaming agent solution containing the sodium salt of an alkyl, aryl or alkaryl sulphonic acid in an aqueous diluent usually employed for foaming, in a ratio sulphonic acid solution to sodium sulphonate solution of 1:1 to 1:4, the pH value being adjusted to 0 up to 3 and said mixture being foamed together with a urea formaldehyde resin precondensate solution in the usual manner.

Abstract: Plastics are produced by reacting at least one compound containing sulfonic acid groups with at least one aldehyde in the presence of a hydroxy compound in an acidic concentrated aqueous solution having a water content of about 20 to 30% by weight. If a tenside is present the reactants will form a foam. The preferred sulfonic acid-containing compound is the sodium salt of diisobutylnaphthalene sulfonic acid, the preferred hydroxy compound is a phenol, vix. resorcinol, and the preferred aldehyde is formaldehyde which may be formed in situ from hexamethylenetetramine, paraformaldehyde, trioxane, or the like.