Metal-complex Dyes
Metal-complex dyes that are otherwise known as
pre-metallized dyes shows great affinity towards protein fibers.
Generally it has been seen that metal complex dyes are Chromium or
Cobalt complexes. Among the popular metal-complex dyes, a variety known
as 1:2 metal-complex dyes finds application for dyeing polyamide fibers.
For dyeing wool, metal complex dyes are the most favoured. The following
table shows a comparison between 1:1 metal-complex and 1:2 metal
complex dye.
Metal-complex dyes generally cannot be said as
belonging to a particular application dye class. In fact, Metal-complex
dyes belong to numerous application classes of dyes. For example, they
are found among direct, acid, and reactive dyes. When applied in the
dyeing processes, metal-complex dyes are used in pH conditions that is
regulated by user class and the type of fiber type (wool, polyamide,
etc). The pH levels for wool typically ranges from:
Chemically speaking, Metal copmplex Dyes can be
broadly classified into two classes. 1:1 metal-complexes, where, one dye
molecule gets co-ordinated with a single metal atom. In 1:2 metal
complexes, one metal atom is co-ordinated with double dye molecules. The
dye molecules are typically a monoazo structure which can contain
additional groups like hydroxyl, carboxyl or amino groups. They can form
strong co-ordination complexes with transition metal ions, like Nickel,
Chromium, Cobalt and Copper. One point to note here is that
phthalocyanine dyes are not classified as metal-complex dyes. Typical molecular structures of 1.1 metal-complex dyes Typical molecular structures of 1.2 metal-complex dyes
Metal Complex Dyes is using for a variety of
applications like wood stains, leather finishing, stationery printing
inks, inks, coloring for metals, plastic etc. |