GB960329A - Process for treatment of cellulosic fabric with formaldehyde - Google Patents

Abstract

Cellulosic fabrics are rendered crease resistant and dimensionally stable by wetting them with an aqueous medium, treating them with a dehydrating solution containing formaldehyde to partially react the cellulose with the formaldehyde and then treating them with a latent catalyst for the cellulose-formaldehyde reaction which becomes effective upon heating. The fabric may be wetted with a dilute aqueous solution of a strong acid or salt of a weak base with a strong acid, e.g. phospheric, hydrochloric, hydrobromic, sulphuric, trichloroacetic, formic or toluene sulphonic acid or ammonium chloride or sulphate, or water alone, adjusted to a water content of 10-100% by weight, treated with a dehydrating solution which may be an anhydrous solution of glacial acetic acid containing traces of acetic anhydride or an aqueous solution containing 40-70% by weight of calcium chloride hexahydrate and which may contain 3-20% by weight of formaldehyde, washed with cold water, dried at a temperature below 150 DEG C. treated with 0.5-6% by weight of latent catalyst, e.g. magnesium chloride, zinc nitrate, aniline hydrochloride, ethylamine hydrochloride or ethylene diamine dihydrochloride, dried at a temperature below 150 DEG C., cured at a temperature of at least 150 DEG C., washed and "Sanforized" (Registered Trade Mark). Alternatively the fabric may be wetted with an aqueous solution containing an anionic, cationic or narionic wetting agent, numerous examples of which are given, and then treated with the dehydrating solution containing formaldehyde and an acid. The fabric may be pretreated with a starch or curable crease-proofing resin, e.g. a urea-aldehyde, amino-triazine-aldehyde, tetrahydro-5-hydro-2(IH)-pyrimidone-formaldehyde, cyclic ethylene urea-formaldehyde, urea formaldehyde, triazone-formaldehyde or epoxy resin. The solution of the latent catalyst may contain hard builders, softeners, waterproofing agents, oil repellents fungicides or fireproofing agents. The fabric may be washed with hot soapy water after treatment with the latent catalyst and prior to drying. Permanent creases or pleats may be formed in apparel by fashioning the fabric after treatment with the latent catalyst and drying into apparel and creasing or pleating with a hot iron. The fabric may be embossed after treatment with the latent catalyst prior to drying and curing. Fabrics comprising cotton, linen, hemp, jute, ramie, sisal viscose or cuprammonium rayon, cellulose acetate cellulose acetate-propionate, cellulose acetate butyate, or ethyl cellulose fibres alone, or in admixture with nylon, polyacrylonitrile or polyester fibres, may be treated.