GB649642A - Improvements in processes for imparting flame-resistance to fibrous materials or mildew-resistance to fibrous materials - Google Patents

Abstract

Cellulosic fibrous materials are proofed against fire and mildew by chemically combining the material with an amount of, from 1 to 5 per cent of phosphorus or sulphur and from 0.25 to 6 per cent of nitrogen, the amounts being based by weight on the washed and dried material, the combination being effected by impregnating the material with an aqueous solution of a mixture of, or the reaction product of (1) one or more water-soluble acids of phosphorus or sulphur or salts thereof whose basic part is volatile in the process, and (2) one or more basic nitrogen-containing organic compounds which have an atomic ratio of carbon to nitrogen of not more than 2 : 1; drying the material, heating the dried material to a temperature between 250 DEG to 400 DEG F. for 30 seconds to 2 hours, and washing and drying the heated material, the pH of the heated material prior to washing being between 3 and 6. Specified acids are pyrophosphoric, orthophosphoric, orthophosphorous, pyrophosphorous, sulphuric acid, sulphamic, phosphamic, diamidophosphoric, dinitride hexaphosphoric acid and fluorophosphoric acid. Specified salts of acids are ammonium-, dimethylamine-, isopropylamine-, guanidine-, guanyl urea-, urea-phosphate, guanylurea sulphate, and carbo hydrazidine pyrophosphate. Specified nitrogen-containing organic compounds are urea, biuret, cyanacetamide, semicarbazide, dicyandiamide, acetamide, formamide, melamine, phenol-guanidine, methyl urea, guanidine, carbohydrazidine, dihydroxyguanidine, guanylurea, oxalamidine, biguanidine, guanidine carbonate, amino-guanidine acetate, guanylurea formate, biguanidine borate. Specified cellulosic fibrous materials are cotton, viscose rayon, e.g. knitted fabrics, duck, paper and wood. Other ingredients may be included in the aqueous solution, e.g. aldehydes to avoid swelling of the fibres, the specified aldehydes being formaldehyde, acetaldehyde, acrolein, and aldol; buffers such as ammonium-, sodium-, potassium-hydroxide, diethylenetriamine or triethanolamine; nitric acid, glyoxal or chloral hydrate may also be incorporated in the solution. The fibrous materials may be after-treated or pre-treated, e.g. bleached, mercerized, parchmentized, dyed, printed, sized. Specification 648,883 is referred to.