Лако-красочные материалы — производство

These two dyes were recently added to the sample card of the acid — and milling fast Polar dyes of the J. R. Geigy A. G. firm. Since methods for preparing milling-fast azo dyes have not been patented by this firm for several years, it is assumed that the two Polar brilliant red dyes either come under an old disclosure or are not patentable at all.