Cationic Dyes for Paper, Leather, and Other Substrates

2 Cationic Dyes for Paper, Leather, and Other Substrates 

Cationic dyes were the first synthetic organic dyes employed for dyeing leather, initially for dyeing of vegetable-tanned leather. Currently, brilliant cationic dyes are used for enhancing the brilliance of the shades obtained with 1 2 metal-complex dyes. 

Because of their coloring strength, cationic dyes are used in the office supplies industry for the manufacture of ink, typewriter ribbon, and copying paper. 

Colorless derivatives of the carbinol bases of cationic dyes have recently found application for the manufacture of carbonless copy paper and for special paper used for thermal printers. Examples of such color formers are the crystal violet derivative 31 [29], which develops a blue color, and the black-developing fluorane lactone 32 [30] and benzoxazine 33 [31], 

Cationic dyes which absorb in the near-infrared region of the spectrum are used in optical data storage disks, e.g., 34 [32]  

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