PROCESS FOR OPTICAL BRIGHTENING OF POLYACRYLONITRILE FIBER MATERIALS

摘要

1288545 Optical brightening FARBWERKE HOECHST AG 29 Jan 1970 [30 Jan 1969] 4340/70 Heading DIP Fibrous materials of polymers comprising at least 85% of polyacrylonitrile are optically brightened by impregnating the material with a liquor containing a brightener of general formula in which A represents a branched or unbranched C 2-4 alkylene group, R1 represents a C 1-4 alkyl group, R2 represents a C 1-4 alkyl group or the two radicals R2 together with the nitrogen atom form a saturated heterocyclic ring, X represents a colourless anion and n is 1 or 2, adjusting the liquor content of the material to 5-120% by weight referred to the material and heating, preferably with steam, for 2 seconds to 30 minutes at 100‹-150‹C. If the brightened fabric is to be printed immediately it is preferably subjected to intermediate drying at 50‹-150‹C. Thickeners, for example, starch ether, tragacanth, carob bean flour and crystal gum, are added to prevent migration of the optical brightener during drying. Enhanced brightening is achieved when a non-ionic condensation product of a fatty acid and oxyethylated ammonia and/or a quaternary condensation product of a fatty acid and a low molecular weight aliphatic polyamine is added to the brightening liquor. A second brightener of general formula in which A, R1, R2, X and n have the meanings specified above, shows a greenish-blue fluorescence and is able when applied in admixture with the compounds of formula II, to compensate the reddish tint of the latter.