| abstract |
1,177,429. Oxonol dyes. ILFORD Ltd. 27 Sept., 1968 [27 Sept., 1967], No. 43942/67. Heading C4P. [Also in Division G2] The invention relates to symmetrical polymethine-oxonols of formula wherein n = 1 or 2 and R 1 is a group comprising COOH and/or SO 3 H. In the examples R 1 is 4<SP>1</SP>-sulphophenyl, 2<SP>1</SP>-methyl-3<SP>1</SP>-amino-5<SP>1</SP>-sulphophenyl, 4<SP>1</SP>-amino-5<SP>1</SP>-sulphophenyl and 4<SP>1</SP>-carboxyphenyl. Reference is made to alkali metal and triethylamine salts. The dyes are prepared by usual condensation methods and are used as filler, antihalation and acutance dyes. |