GB658994A - Improvements in or relating to controlling the shrinkage of textile materials consisting wholly or partly of wool - Google Patents

Abstract

Textile material consisting wholly or partly of wool is impregnated with a urea-aldehyde condensation product or a condensation product of an aldehyde with an aliphatic or heterocyclic amino compound or an alkylated derivative of such condensation products or a mixture thereof, and a small amount of free formaldehyde, and the condensation product is cured on the material, preferably by the application of heat. The treated material has improved resistance to shrinking. The impregnation may be carried out by immersion in or spraying with a bath (preferably aqueous) containing the condensation product and formaldehyde, or the condensation product may be applied in an anhydrous or substantially anhydrous bath wherein diluents such as ethyl, propyl and butyl alcohols may be used. An acid catalyst such as zinc chloride, oxalic acid, diammonium hydrogen phosphate, acetic acid or ethyl ammonium phosphate is preferably added to the bath. From 4 to 16 per cent of solid condensation product, 2 to 6 per cent of free formaldehyde and from 1 to 3 per cent based on the condensation product of an acid catalyst such as diammonium hydrogen phosphate are the preferred amounts in the bath. Paraformaldehyde or other formaldehyde-yielding materials may be used in place of formaldehyde. The bath temperature may be from 40 DEG to 100 DEG F. The process is applicable to unwoven wool, yarns, flannels, felts, fabrics, shirtings, knit goods and blankets made of wool or wool in combination with rayon, cotton, silk, casein and zein. In an example, samples of an all-wool shirting fabric are treated in baths containing (a) 22 per cent monomethylol urea and 3 per cent diammonium hydrogen phosphate (based on the weight of condensation product); (b) 15 per cent free formaldehyde and 3 per cent diammonium hydrogen phosphate (based on the weight of formaldehyde); and (c) 16 per cent monomethylol urea, 6 per cent free formaldehyde and 3 per cent diammonium hydrogen phosphate (based on the weight of condensation product). After curing at 290 DEG F., and subjecting to three standard washings, the third sample was found to possess the least shrinkage.