de - Beste verfügbare Techniken (BVT) - Umweltbundesamt

Chapter 1
1.3.6 Optical brighteners
[2, Onken, 1996, 6, Ullmann, 2001]
Optical brighteners or, more accurately, fluorescent whitening agents, are colourless to weakly
coloured organic compounds that, in solution or applied to a substrate, absorb ultraviolet light
(e.g. from daylight at c. 300 – 430 nm) and re-emit most of the absorbed energy as blue
fluorescent light between c. 400 and 500 nm. In daylight, optical brighteners can thus
compensate for the aesthetically undesirable yellowish cast found in white industrial substrates,
such as textiles, papers, or plastics. Figure 1.15 gives some examples.
R
R
N
N
N
N
NH CH CH
R SO 3H
N
R R
R
(a) (b)
SO 3H
14 Dezember 2005 OFC_BREF
R
NH
O O
(a) Diphenyl pryrazolines (b) Coumarins (c) Stilbenes
Figure 1.15: Examples of some optical brighteners
(c)
R
R
N
N
R
R
N
R