GB700810A - Improvements in or relating to nitrogen-containing thermosetting resins having aliphatic sulphate and sulphonate residues and to a process for preparing the same - Google Patents

Abstract

Nitrogen - containing thermosetting resins containing aliphatic sulphonate or sulphate groupings are prepared by condensing in water 1 mol. of an amino compound, an aldehyde, .05- .5 mol. of a water soluble salt of a compound NH2 - R - X (where R = saturated alkylene of 1 - 5 carbon atoms and X = SO3H or SO4H). Amino compounds which may be used are urea, thiourea, cyanamide, dicyandiamide, guanidine. Aldehydes mentioned are formaldehyde, its polymers, acetaldehyde, propionaldehyde, benzaldehyde and furfural. Compounds of formula NH2 - R - X mentioned are taurine (2 - amino ethane sulphonic acid); amino ethane sulphuric acid; 1 - aminopropane - 2 sulphonic acid; 1 amino butane - 2 - sulphonic acid; b - aminopropane - 2 - sulphonic acid and 1 - aminopropane - 2 - sulphuric acid. Sodium, potassium and lithium salts are referred to. Preferably methylol compounds are formed in alkaline solution, the sulphate or sulphonate is added, the solution concentrated (e.g. by flash concentration if desired at reduced pressure), acidified and heated. The solution is finally stabilized by addition of alkali. The products may be used for ion - exchange, treating textiles, or, especially, for addition to paper pulp, precipitation on the film with alum and curing in the formed paper (see Group VIII). In the examples condensation products are prepared from 1 mol. urea, 2.7 mols. of formaldehyde at a pH of 7.5 - 8.0. After some initial condensation 0.2 mols. of the sodium salt of either taurine or 2 - amino ethane sulphinic acid were added, and the mixture concentrated at reduced pressure. The solution was then acidified and heated under reflux to a viscosity of 5 poises, neutralized and cooled. The resin solution was then added to paper pulp and precipitated on the fibres with aluminium sulphate.