Reactive Dye
History
Two chemists of ICI company (UK) named
Stephen and Rattee
invented a Reactive Dyes in
1956
- Chlorotriazines
•The first three reactive
They were awarded gold medal of dyes were -
the society of dyers and ✔ PROCION YELLOW
colorists(SDC) for the year 1960 ✔ PROCION BRILLIANT RED 2B
✔ PROCION BLUE 3G
Reactive Dye
• A dye, which is capable of reacting
chemically with a substrate to form a
covalent dye substrate linkage, is known as
reactive dye.
• Here the dye contains a reactive group and
this reactive group makes covalent bond
with the fiber polymer and act as an
integral part of fiber.
Reactive Dye - Reasons for so named
• Reactive dyes form covalent bond with
the fiber and becomes a part of the
fiber. This type of dyes have some
reactive group which can react with
–OH group of cellulose and –NH2 group
of protein fibers. Due to this fact these
dyes are known as Reactive dye.
General Features of a Reactive Dye Molecule
W = water solubilising group
D = chromophore
B = bridging group
RG = reactive group
X = leaving group
Reaction
D-SO2-CH2-CH2-O SO3Na + HO- cell →
D-SO2-CH2-CH2-O-cell + NaHSO3
D-SO2-CH2-CH2-O SO3Na + NH2- wool →
D-SO2-CH2-CH2-NH-Wool + NaHSO3
Here, D = dye part.
Wool = wool polymer.
Cell = cellulosic polymer.
Properties of reactive dye
• Soluble in water.
• During dyeing the reactive group of this dye
forms covalent bond with fiber polymer
and becomes an integral parts of the fiber.
• These dyes are normally used for dyeing
cellulose and protein fibers (Wool, Silk &
Polyamide).
Properties of reactive dye
• Reactive dyes are found in powder, liquid
and print paste form.
• All types of shades are available from these
dyes.
• The dyeing is done in alkaline medium (pH
= 10.5-11.5).
• Colorfastness is well (Wash & Perspiration).
Properties of reactive dye
• The brightness and rubbing fastness are
comparatively well.
• Relatively Cheaper.
• The dyeing process is very easy.
• Certain amount of dyes are hydrolyzed
during dyeing (10-40%).
• Very popular and widely used in WPI in
Bangladesh.
Reasons of being Popular
• Ability to produce bright
shades of wide range.
• High leveling quality.
• Good washing fastness.
• Good light fastness.
• Simple dyeing method
therefore one stage dyeing.
• Low temperature dyeing
(below 1000C)
• Lower cost, i.e. cheaper.
Classification
• On the basis of reactive group:
1. Halogen containing
– Chlorotriazines (Cibacron, Procion, Basilen)
– Pyrimidine [Drimerene(X1=X2=Cl), Reacton,
Levafix(X1=CH3,X2=SOCH2)]
– Quioxaline (Levafix E)
– Pyridazone (Primazin)
2. Activated Vinyl Compound
– Vinylsulphone (Remazol)
– Vinyl Acrylamide (Primazin)
Classification
• On the basis of temperature:
1. Hot Brand(80 degree)
2. Cold Brand(40 degree)
3. Medium Brand(60 degree)
• On the basis of reactivity:
1. Highly reactive
2. Moderate reactive
3. Lower reactive
Trade Name
Trade name Manufacturer Country
Procion I.C.I U.K
Cibacron Ciba Switzerland
Remazol Hoechst Germany
Levafix Bayer Germany
Reactone Geigy Switzerland
Primazin BASF Germany
Drimarine Sandoz Switzerland
Chemistry
&
Mechanism
Principles of Dyeing
• Migration of dye molecule from liquor to
fiber surface. This process is assisted by
increasing temperatures and using
auxiliaries – substances that help the dyeing
process.
• Diffusion of dye from the fiber surface into
the core of fiber. This process is assisted by
agitation of the fiber, dyebath or both
together with heat.
Principles of Dyeing
• Fixation ensures the dye molecule is
attached to the fiber either by physical
forces or chemical bonding. These forces
may be weak or strong.
• Most dyeing process need heat to provide
the energy for the dyeing to take place.
This is commonly supplied by direct or
indirect steam.
Characteristics of reactive group of reactive dye
• Reactive groups do not contribute to
the color of dye. Chromogen group
imparts it.
• The reactivity of vinyl sulphone group
is less than that of halogen group.
• If no. of reactive group increases,
binding also increases.
• Reactive dye absorb up to 90%.
Characteristics of reactive group of reactive dye
• Molecular weight of reactive group 69-211
g/ mole.
• If the molecular weight of reactive group
increases, reactivity increases.
• Chlorine imparts medium reactivity, but it
is cheap.
• Reactivity of fluorine is the least and its
hydrolysis rate is also less.
Characteristics of reactive group of reactive dye
• Reactivity of vinyl Sulphone group increases
with increasing temperature and pH.
• Sulphone group has more solubility but it is
not stable.
• Generally low molecular weight dyes are of
hot brand.
• Less affinity dyes are used for pad method.
