HYDRATES OF THE DISODIUM OR DIPOTASSIUM SALT OF 4,4'-BIS(2-SULPHOSTYRYL)BIPHENYL AND THEIR USE IN AQUEOUS FLUORESCENT WHITENING FORMULATIONS FOR PAPER OR TEXTILES

摘要

The invention relates to novel hydrates of the disodium or dipotassium salt of 4,4'-bis(2-sulphostyryl)biphenyl which are characterised by their water of hydration content, to associated crystal forms characterised by their X-ray diffraction diagram, to processes for preparing same, and to the use thereof for preparing concentrated formulations of optical brighteners.