GB1534752A - Highly sulphonated triphenylmethane compounds process for their preparation and their use as dyestuffs - Google Patents

Abstract

1534752 Sulphonated triphenylmethane dyestuffs HOECHST AG 6 Feb 1976 [6 Feb 1975] 04718/76 Heading C4P The invention comprises sulphonated triphenyl methane dyes of the general formula wherein R 1 <SP>I</SP>, R 1 <SP>II</SP> and R 1 <SP>III</SP>, which may be different are H, halogen, C 1 -C 4 alkyl or C 1 -C 4 alkoxy, R 5 is H or a group R 2 <SP>I</SP>, R 2 <SP>II</SP>, R 2 <SP>III</SP>, R 3 <SP>I</SP>, R 3 <SP>II</SP>, R 3 <SP>III</SP>, R 4 <SP>I</SP>, R 4 <SP>II</SP> and R 4 <SP>III</SP>, which may be different, are H, halogen C 1 -C 4 alkyl, C 1 -C 4 alkoxy, phenyl, phenoxy, phenylamino, benzyl or phenethyl, or two of these groups together with the benzene ring to which they are bound form a naphthyl or an anthroquinone radical, at least one of R 2 <SP>III</SP>-R 3 <SP>III</SP> if present being other then H, A is H, NH 4 , N(R) 4 or a metal equivalent and the R groups which may be different are alkyl which may be substituted by one or more hydroxy or alkoxy groups, or two R groups together with the N atom form a piperidine or morpholine radical and n is an integer from 3 to 6. The dyes are prepared by sulphonating the triphenylmethane base, or a salt thereof, wherein 3>n#0 or a mixture thereof with oleum (e.g. 5-40% SO 3 ) or chlorosulphonic acid at 40‹-120‹ C. The invention further comprises dyestuff concentrates comprising 5-80% by weight of one or more dyestuffs and 20-95% by weight of water; up to 30% by weight of a water miscible organic solvent may be present and the concentrates have a pH of 0À5 to 4À0. The dyestuffs are used in fountain pen or fibre or felt tip pen writing inks.