BASIC DYE

Basic or cationic dyes are colored cationic  salts  of  amine   derivatives. Basic dye  cations will  migrate toward negative charges  inside   the

fiber. The  dyes  may  be  applied to cellulosic,    protein,   nylon,  acrylic, and

specially  modified  synthetic  fibers. Although the dyes  generally  are  of

striking  brilliance  and  intensity,  the colorfastness    of  the  dyes  on cellulosic,   protein, and  nylon   fibers  is  generally poor. Colorfastness can  be

improved through   mordanting with tannins or  other  complexing  agents. Since

the  insoluble parent  amine is  regenerated  from basic dyes  at  basic  pH,  the

basic  dyes  are applied   from  mildly  acid   or neutral   solutions. The  dyes  are

also  important in "one-shot  dyeing" of paper products.