Aq. flameproofing compsn. for cellulose prods. - esp. paper, contg. aluminium sulphate, dicyandiamide and opt. formaldehyde

摘要

An aq. compsn. for flame-proofing cellulosic materials by impregnation contains Al2(SO4)3 and dicyandiamide, and opt. a small amt. of HCHO. Impregnation is of paper. The paper may be for decorative or packing purposes. Cardboard and wood pulp can also be treated. Cellulose fibres and prods. such as paper are not damaged by the compsn. The rate of impregnation is higher than with NH4 salts. Cheap, easily available Al2(SO4)3 can be used, since the hydrolytic effect on cellulose is suppressed by the presence of dicyandiamide. The compsn. esp. contains 90-60 wt.% of Al2(SO4).18H2O and 10-40 (15-25)% of dicyandiamide. The mixt. is used as a 25-20% aq. soln.; this is stable at room temp. If HCHO is added, the molar ratio of HCHO:dicyandiamide is 0.1-0.9:1 (0.25-0.5:1); addn. of HCHO makes it possible to prepare a stable 40% aq. soln.