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DYEING MECHANISM
, --. . ,
--_._-_____.. _.
* EXHAUSTION
* ABSORPTION
* DIFFUSION
* MIGRATION
* FIXATION
i i
DYEING MECHANISM
AFFINITY -> DYEDISSOLVED <- -' DYEFIBER
SOLUBILITY DYE^^^^^ <-
DYE IN DYEBATH <- CONVECTIVE DIFFUSION ->
DYE I N BOUNDARY LAYER <- MOLECULAR DIFFUSION ->
DYE ON FIBER SURFACE <- DIFFUSION IN FIBER ->
I F f" fl ids
DYE I N FIBER C- FIXATION/CHEMICAL REACTION ->
IMMOBILIZED DYE
DYEING MECHANISM
A F F I N I T Y -> DYEDISSOLVED '- -> DYEFIBER
SOLUBIL ITY DYESOLID
S P E C I F I C AFFINITY OF THE DYE FOR THE F IBER BY HYDROGEN BONDING, VAN DER WAALS FORCES, OR I O N I C INTERACTION WHICH MAY OCCUR AT SPECIF IC SITES, BY ELECTRICAL EFFECTS OR THE FORMATION OF BONDS.
MECHANICAL ENTRAPMENT OF THE DYE WITHIN THE FIBER, ESPECIALLY BY ( qc Ais L A L ) RENDERING THE DYE INSOLUBLE BY CHHEMICAL
REACTION ( I N WHICH THE FIBER MAY OR MAY NOT PARTICIPATE).
BINDERS HOLD PIGMENTS I N PLACE ON THE F IBER SURFACE.
i
DYEING MECHANISM
SOLUBILITY -> DYEDISSOLVED <- DYEFIBER DYESOLID <-
DYEING MECHANISM DYESTUFF/FIBER EXAMPLE
SIMPLE D I S T R I B U T I O N DISPERSE/SYNTHETIC
S P E C I F I C A F F I N I T Y ACID/WOOL ACID/NYLON BASIC/ACRYLIC DIRECT/CELLULOSIC
ENTRAPMENT VAT/ C ELLU LOS I C SULFUR/CELLULOSIC NAPHTHOL/CELLULOSIC
- 7 F I B E R REACTIVE/CELLULOSIC
BINDING PIGMENT/ALL FIBERS
DYEING MECHANISM
0 0
dyebath cellulose
equilibrium = [F]bath -+ + [FlCel
substantivity \ = p( [[kk!h) i i
I
General Fixation Characteristics of Major Dyeclasses
Basic Dyes
Metal Complex Dyes
Azoic Dyes
Acid Dyes
Disperse Dyes
Vat Dyes
Direct Dyes
Reactive Dyes
Sulphur Dyes
0 20 40 60 80 I 0 0
General % Fixation
ECG017
Ideal Exhaustion Rate Maximum Total Exhaustion Split Salt Addition =
Temperatur 1 'e e 00 90 80 70 60 50 40 30 20 I O 0
I C - - YQ EX
0 20 40 60 80 100 120 140
iaustion
Time Minutes
- TimelTemperature L-1 ....,.......... >,.>:.>,,., .......,,/ ....A . . . O/o Dye Exhaustion
Substantial increase in cotton consumption in recent years
Concern about some technical/ environmental drawbacks of alternative dyeing methods
Strong demand for bright and deep shades
Convenient, economical dyeing methods
i
2-
equilibrium
1 OH- absorption in fibre
hydrolysis in bath hydrolysis in fibre
OH-
equilibrium
C EL-f i bre amQb R(eactive) system
I Chromophore 1
fibre - dye bond 1 OH-, H', oxydants
bond hydrolysis
dye affinity
dye concentration \
liquor ratio
type of fibre
z PH
electrolyte concentration
temperature \
I i
Cellulose in water carries a negative charge on its surface. Reactive dyes also carry a negative charge leading to a natural repulsion between dye and fibre.
. .... ..... ~ L., ::. .. .j., ., ..:::.. ,,,,,
‘4 . ..... ....
Addition of inert electrolytes such as common salt (NaCI) or Glauber’s salt (Na,SO,) suppresses the electrostatic repulsion between dye and fibre.
i
Washing-Off mechanism of Reactive Dyes ... ..
Removal of unfixed hydrolysed dye, salt, alkali, auxiliaries from fibre surface
Removal of unfixed hydrolysed dye, salt, alkali, auxiliaries from fibre inside
PHASE I Favourable conditions:
high number of bath changes high liquor ratio in each bath strong mechanical agitation of bath (high speed of bath circulation)
t,: ; '6 .-. (4 0 > . < *Ld dye 0 unfixed, hydrolysed dye X chemicals
ECARE8
PHASE 2 Favou ra ble conditions:
high temperature of bath low amount of unfixed, hydrolysed dye low electrolyte concentration in the bath factors (low water hardness) high liquor ratio ineacniath = high
gradient high number of bath changes and of course low affinity, small dyestuff molecule main with high diffusion factor
main
The Cibacron Approach
hot dyeing systems warm I cold dyeing systems
all range names mentioned are registered trademarks of the respective producers
(Procion MX)
(Levafix EA, Drimarene RIK)
(Levafix E)
(Cibacron F, Levafix EN)
(Cibacron LS)
(Cibacron C)
(Cibacron E, Procion H/HE) (Sumifix Supra, Basilen FM) .
(Drimarene X) increasing reactivity
via R1
via R2
/-
...... ..____
B ridg elbridge
Headlhead
Headltail
R1 R2
- R1- R2
R I - R2
Headlbridgel tail
R1 2 R3
R I Headlheadl tail
R2 R3
R = reactive group
i
, , ._ , ~ ~En”iro.ca.r-e--6~ _ _ . . . . . . . . . .. . . . . .. .. . . . .I_....ii___ . . . . . . . .. . . . . . . ..
Re- leased
1957
1970 -
1957
1970 -
1980
1984
Reactive groups
MCT I MCT
vs I vs
MCT I VS
COOH N
C u rre n t ma n u fact u re r( s), trade name(s)
IC1 Procion H-E Ciba Cibacron E etc.
(part of the ranges)
~~ ~~
Hoechst Remazol (two dyes, mainly: Remazol Black 6 )
Sum i tom0 Sumifix Supra Hoechst Remazol S
(2 dyes)
Nippon Kayaku Kayacelon React
“bridge”
“ headhail”
“ h eadl h ead”
“ bridge”
Uses ( p referred)
- exhaust (8OOC)
- pad-batch - pad-dry-pad-steam - exhaust (40° - 6OOC)
- exhaust (6OOC)
- exhaust (>lOO°C) (1 3OoC for PES/ CO)
all range names mentioned are registered trademarks of the respective producers
(continued)
leased
1993
1994
_ _ _ _ _ ~
Reactive groups
MCT / VS / VS FT / VS arom FT / VS aliph
FT I FT vs / vs vs / vs
MCT I VS
FT/FT MCTNSNS
Current man ufac tu re r( s), trade name(s)
Ci ba Cibacron C
BASF Basilene FM (4 dyes)
Ci ba Cibacron LS
mainly: “headlhead”
also: “bridge” (1)
‘I headltail” (I)
“headlhead” or
” bridge” or
“headlbridgel tail”
“bridge” or
“headlbridgel tail”
Uses ( p referred)
~~ _ _ _ _ _ ~ ~ _ _ _ _ _ _ ~
- pad-batch - pad-dry-pad-steam - low liquor ratio
exhaust (50° - 6 O O C ) - pad -direct-steam
- pad-batch - pad -d ry-pad -s tea m - exhaust (6OOC)
- exhaust (7OOC)
all range names mentioned are registered trademarks of the respective producers
i i
- __-_--
I VS bireactive dyes:
>
Efforts to fix the (already formed) bond between the VS and the fibre. An unstable situation arises involving fixation and hydrolysis at the same time.
component endangers the
I vs
S
Thus any pH acceptable for fixation of the VS group is high enough to fix the
The fragile VS-fibre bond is not endangered unnecessarily. group as well.
x
Z (v
I
0
I
0
0
u)
II 64
I
-o
i=
=
b=
l
tn a-
a- x"
p:
,Degree of Fixation - nvl
. . . ... __-
. .
Dye = R I
H y d x Fixation
Dye-OH Dye-R-OCel
, --
_...,. ....... _..-..
R1 - Dye - R2 I
Hydrolysis Fixation 75c---- 75%
v v CelO-Rl-Dye- R2
HO - Dye - R2
Hydrolysis I Fixation
f
HO-Dye-OH HO-Dye-RZ: -0Cel
The Cibacron Approach
i
Cibacron C, Degree of Exhaustion and Fixation
. . . . I
2 % dyeings on CO n.merc., Liquor rafio 6: l
Yellow C-R-01
Orange C-G
Red C-2G
Red C-R
Blue C-R
Navy C-B 00%
EcareSr
Yo OOC 06 08 OL 09 OS OP OI 02 OC O
i
ClBACRON@C in a Nutshell
Two (or three) reactive groups yields: for fast diffusion facilitates:
D Small and I or flexible molecules
High Fixation @ Washi ng-off 3 Resistance to Hydrolysis GI Levelling
> Optimized pair of reactive groups ensures homogenious dyeing properties in: ensures:
D Highly soluble chromophores and I or reactive systems
0 Reactivity Ease of Use o Affinity 2 Solubility 0 Levelling
0 Reproducibility (no dye precipitation)
’’\> Low I medium affinity chromophores Compact range ensures: ensures: QEase of Use
C Fast Diffusion c Low Risk of Tailing
oLess Human Error
ECare17r
(3 z
w t. n n
a n
t)
8 z 0
w 0
a
m 0
cn Q)
0
I.
a
Q)
S
Q)
>
0
L
I.
U
-
L 0
el ---
a
0
W
2
I
Washing-Off Properties of Cibacron C Dyes . ............ . _..._ __._..ll........ __ ..-----
Very Low Propo of Unfixed Dye
(in Fibre and Bath) Extraction of Unfixed
ECARE3 The Cibacron Approach
7
Daphnia pulex Sodium chloride LC 50 2373 ppm Sodium sulfate LC50 2765 m m
Gambusia affinis Sodium sulfate Morone saxalitis (larvae) Sodium sulfate
LC 50 120 ppm LC50 250ppm . .
LC 50 = 50% mortality in test (exposure 24 - 96 hours) LC 0 = Highest limit without mortality
Morone saxalitis (a few cm) Sodium sulfate LC 50 3500 ppm . I
Salmo gairdneri Sodium sulfate Lepomis macrochirus Sodium sulfate
I .
LC 0 750ppm LC 0 8700 ppm
.pj]gI&Q a &
dyeing of cotton and viscose with reactive dyes
/-- ,* q Q:/yJ$T d
dyeing of cotton with direct dyes effluents from ion-exchangers (used to soften process water) application of FWAs on cellulosic fibres cutting-agents for standardization of some dye ranges levelling agents in dyeing of PAC and wool dyeing of cotton with some vat, sulphur or naphthol dyes
0 ;p,&q))t a
35 tons/ day of cotton (knit) 6 days/ week schedule 30 Yo bleached white /70% dyed I O : 1 average liquor ratio (exhaust dyeing) I 8 gallons of water per pound of treated fabric reactive dyes daily effluent volume: > 1.3 million gallons
Q) eh@ a
2500 DDm I I if 60 g/l electrolyte is used (medium to deep shades)
(>3500 rmm 1 . 1 . when black/ navy is dyed)
3
yl 0
Q)
tn S
a 0 Q
) 9
Q
)
9
tn tn 0
U
)r S
0
- .I
m
F
/- fj uorotriazine g rou p a
d e activated medium reactivity stable fibre-dye bonds (alkali, chlorine, peroxide) bonds stable to acid, thanks to two groups
igh solubility
/
exclusive patented' bridge
gives molecule good flexibility selected for maximal sol u b i I i ty
F
contribution to high
high color strength possibility to improvi fastness or shade
affinity
Q) z
0
S 0
E
C
0
x 'i
=a
F ........._._..... .. 1.
1.1 -.
...
S
0
;Ip' u- -7
...................................................................... .......... - ...............
. . . . . . . . . . . . . . . .
- Q,
0 0 I
Q,
%
U
I
0 I
a, U
__. - * L EnviroCare 8
. .. - .
through
* 1/11 SD, CO non-merc., actual dyeing conditions
gll salt 120
100
80
60
40
20
0
Averages with a similar production volume
I
cn J C
0 m P
E!
i3
0 C
0 m P 0
E! .-
w c 0 (0
E! .- 0
II c
0 m E! n is
A X w
C 0 0
a
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e .-
W
C 0 0
a
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E! .-
% dye 6
5
4
3
2
1
- 0
i
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m
C
0
a
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3 - -
t
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w
0
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