DYEING MECHANISM * FIXATION * MIGRATION * EXHAUSTION * ABSORPTION * DIFFUSION --_._-..

Transcription

1

2 DYEING MECHANISM,--.., --_._-.. * EXHAUSTION * ABSORPTION * DIFFUSION * MIGRATION * FIXATION

3 i i DYEING MECHANISM SOLUBILITY DYE^^^^^ <- AFFINITY -> DYEDISSOLVED <- -' DYEFIBER DYE IN DYEBATH <- CONVECTIVE DIFFUSION -> DYE IN BOUNDARY LAYER <- MOLECULAR DIFFUSION -> DYE ON FIBER SURFACE <- DIFFUSION IN FIBER -> DYE IN FIBER f" fl ids IF C- FIXATION/CHEMICAL REACTION -> IMMOBILIZED DYE

4 DYEING MECHANISM DYESOLID SOLUBILITY AFFINITY -> DYEDISSOLVED '- -> DYEFIBER SPECIFIC AFFINITY OF THE DYE FOR THE FIBER BY HYDROGEN BONDING, VAN DER WAALS FORCES, OR IONIC INTERACTION WHICH MAY OCCUR AT SPECIFIC 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 (IN WHICH THE FIBER MAY OR MAY NOT PARTICIPATE). BINDERS HOLD PIGMENTS IN PLACE ON THE FIBER SURFACE.

5 i DYEING MECHANISM SOLUBILITY -> DYEDISSOLVED <- DYEFIBER DYESOLID <- DYEING MECHANISM DYESTUFF/FIBER EXAMPLE SIMPLE DISTRIBUTION SPECIFIC AFFINITY ENTRAPMENT BINDING DISPERSE/SYNTHETIC ACID/WOOL ACID/NYLON BASIC/ACRYLIC DIRECT/CELLULOSIC VAT/ C ELLU LOS I C SULFUR/CELLULOSIC NAPHTHOL/CELLULOSIC - 7 FIBER REACTIVE/CELLULOSIC PIGMENT/ALL FIBERS

6 DYEING MECHANISM dyebath cellulose equilibrium = [F]bath-+ + [FlCel substantivity i i \ = p( [[kk!h)

7 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 I General % Fixation ECG17

8

9 Temperatur 'e e Split Salt Addition = I O I C - - YQ Ideal Exhaustion Rate Maximum Total Exhaustion TimelTemperature 1 L-...,... >,.>:.>,,.,.,/.A.. O/o Dye Exhaustion EX iaustion Time Minutes

10 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

11 i equilibrium 2- amqb C EL-f i bre R(eactive) system I Chromophore 1 1 OH- absorption in fibre OH- hydrolysis in bath hydrolysis in fibre fibre - dye bond 1 OH-, H', oxydants equilibrium bond hydrolysis

12 dye concentration \ dye affinity electrolyte concentration liquor ratio type of fibre z PH \ temperature

13 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.

14 ~ L.,. ::.....j.,.,..:::..,,,,, Addition of inert electrolytes such as common salt (NaCI) or Glauber s salt (Na,SO,) suppresses the electrostatic repulsion between dye and fibre.

15 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 >.<*Ld dye unfixed, hydrolysed dye X chemicals ECARE8 PHASE 2 Favou ra ble conditions: high temperature of bath low amount of unfixed, hydrolysed dye main low electrolyte concentration in the bath factors (low water hardness) high liquor ratio ineacniath high number of bath changes and of course low affinity, small dyestuff molecule with high diffusion The Cibacron Approach = high gradient main factor

16 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

17 via R1 /- via R2

18 ..... B ridg elbridge R1 R2 Headlhead Headltail RI - - R1- R2 R2 Headlbridgel tail R1 2 R3 Headlheadl tail RI R2 R3 R = reactive group

19 ~En iro.ca.r-e--6~ ~~ ~~ i,._, ~ I_...ii Released Reactive groups C u rre n t ma n u fact u re r( s), trade name(s) Uses ( p referred) MCT I MCT IC1 Ciba etc. Procion H-E Cibacron E (part of the ranges) bridge - exhaust (8OOC) vs I vs Hoechst Remazol (two dyes, mainly: Remazol Black 6) headhail - pad-batch - pad-dry-pad-steam - exhaust (4-6OOC) 198 MCT I VS Sum i tom Hoechst Sumifix Supra Remazol S (2 dyes) h eadl h ead - exhaust (6OOC) 1984 N COOH Nippon Kayaku Kayacelon React bridge - exhaust (>loo C) (1 3OoC for PES/ CO) all range names mentioned are registered trademarks of the respective producers

20 ~~ ~~ (continued) _ ~ leased Reactive groups Current man ufac tu re r( s), trade name(s) Uses ( p referred) MCT / VS / VS FT / VS arom FT / VS aliph FT I FT vs / vs Ci ba Cibacron C mainly: headlhead also: bridge (1) I headltail (I) - pad-batch - pad-dry-pad-steam - low liquor ratio exhaust (5-6OOC) - pad -direct-steam ~ 1993 vs / vs MCT I VS BASF Basilene FM (4 dyes) headlhead or bridge or headlbridgel tail pad-batch pad -d ry-pad -s tea m - exhaust (6OOC) 1994 FT/FT MCTNSNS Ci ba Cibacron LS bridge or headlbridgel tail - exhaust (7OOC) all range names mentioned are registered trademarks of the respective producers

21 i i - -_-- I VS bireactive dyes: > Efforts to fix the component endangers the (already formed) bond between the VS and the fibre. An unstable situation arises involving fixation and hydrolysis at the same time.

22 I vs S Thus any ph acceptable for fixation of the VS group is high enough to fix the group as well. The fragile VS-fibre bond is not endangered unnecessarily.

23 (v I II I 64 u) I x Z -oi= =b=l tn a- a- x " p:

24 - nvl ,Degree of Fixation.. Dye = R I H y d Fixation x Dye-OH Dye-R-OCel R1 - Dye - R2 I Hydrolysis Fixation 75c % v v CelO-Rl-Dye- R2 HO - Dye - R2 I Hydrolysis Fixation, -- HO-Dye-OH f HO-Dye-RZ: -Cel _...,... _..-.. The Cibacron Approach

25 i Cibacron C, Degree of Exhaustion and Fixation.... I 2 % dyeings on CO n.merc., Liquor rafio 6:l Yellow C-R-1 Orange C-G Red C-2G Red C-R Blue C-R Navy C-B % EcareSr

26 Yo OOC 6 8 OL 9 OS OP OI 2 OC O

27 i in a Nutshell Two (or three) reactive groups D Small and I or flexible molecules yields: for fast diffusion facilitates: High Washi ng-off 3 Resistance to Hydrolysis GI Levelling > Optimized pair of reactive groups D Highly soluble chromophores ensures homogenious dyeing and I or reactive systems properties in: ensures: Reactivity Ease of Use o Affinity Reproducibility (no dye precipitation) 2 Solubility Levelling \> Low I medium affinity chromophores Compact range ensures: ensures: QEase of Use C Fast Diffusion c Low Risk of Tailing oless Human Error ECare17r

28 cn Q) (3 z w t. n n a n t) 8 z w a m I. a Q) L I. U S Q) - > L el a W

29 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

30

31 Daphnia pulex Sodium chloride LC ppm Sodium sulfate LC mm Gambusia affinis Sodium sulfate LC 5 12 ppm Morone saxalitis (larvae) Sodium sulfate LC5 25ppm.. Morone saxalitis (a. few cm) Sodium sulfate LC 5 35 ppm I I. Salmo gairdneri Sodium sulfate LC 75ppm Lepomis macrochirus Sodium sulfate LC 87 ppm 7 LC 5 = 5% mortality in test (exposure hours) LC = Highest limit without mortality

32 .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

33 ;p,&q))t a 35 tons/ day of cotton (knit) 6 days/ week schedule 3 Yo bleached white /7% dyed I O : 1 average liquor ratio (exhaust dyeing) I8 gallons of water per pound of treated fabric reactive dyes daily effluent volume: > 1.3 million gallons 25 DDm II (>35 rmm 1.1. when eh@ a Q) if 6 g/l electrolyte is used (medium to deep shades) black/ navy is dyed)

34 yl Q) tn S a Q) 9 - Q) 9.I tn tn U )r S m 3

35 F F /- fj uorotriazine g rou pa 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 contribution to high affinity high color strength possibility to improvi fastness or shade

36 ... F C x 'i=a ;Ip' S u _._ Q, I Q, % U Q) z S E I I a, U

37 . - * L EnviroCare through * 1/11 SD, CO non-merc., actual dyeing conditions

38 gll salt Averages with a similar production volume % dye I cn J C E! m P i3 C E! m P.- w c E! (.- I c E! m n is A X w i.- e C a W i.- C E! a - i

39

40

41 m C 3.II - a t.i w

42 P i